研究者詳細 - 迫田　達也

Evaluation of Degradation Degree on Silicone Rubber by Using Surface Discharge 査読あり

Khaing M.T., Hirose N., Miyake T., Sakoda T., Goto S., Anjiki T., Chiba T.

IEEJ Transactions on Electrical and Electronic Engineering 1 - 8 2025年1月

担当区分：責任著者掲載種別：研究論文（学術雑誌）出版者・発行元：IEEJ Transactions on Electrical and Electronic Engineering

Silicone rubber (SiR) insulators in outdoor may be degraded owing to multiple environmental stresses such as ultraviolet (UV) rays, high temperature and pollution adhesion. Evaluation of the degradation degree of SiR can contribute to the long-term maintenance of SiR insulators. We proposed a novel technique to grasp the degradation degree of SiR. The surface discharge (SD) on the SiR surface temporarily decreased the surface hydrophobicity, and then the hydrophobicity recovery time was evaluated. The SD treatments were performed on SiR specimens cut out from unused, 10 and 20-year-aged SiR insulators, and the treatment time was from 5 to 25 s. After each SD treatment, the contact angle was evaluated at intervals of 10 min. As a result, it was found that the contact angle recovery time increases with the increase of SD treatment time. Also, the contact angle recovery times on 10 and 20-year-aged SiR specimens were longer than that on an unused SiR specimen, i.e. the contact angle recovery time after the SD treatment is useful for investigating the degradation degree. © 2025 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC.

DOI： 10.1002/tee.24256

Section Locating of Water-tree Degraded Cable by Measuring Residual Charges Induced by Induced Voltage Pulses 査読あり

Watanabe K., Sakoda T., Takahashi A., Negishi N., Miyazaki K.

IEEJ Transactions on Fundamentals and Materials 145 ( 1 ) 23 - 29 2025年1月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEJ Transactions on Fundamentals and Materials

To establish a novel section locating technique for a water-tree degraded 22 kV cross-linked polyethylene (XLPE) cable that is included in another undegraded cables, we measured a reflected injection pulse at the impedance mismatch which is dependent on water trees. The injection pulse was propagated into cables to be measured, and the measured arrival times of reflected pulses containing residual charges due to water trees were varied depending on the locations of water-tree degraded cables. The section locating was achieved by using arrival time of the reflected pulse.

DOI： 10.1541/ieejfms.145.23

Partial Discharge and Electrical Treeing Phenomena Within Two Spherical Voids in Epoxy Resin 査読あり

Htet S.Z.L., Kondo T., Khaing M.T., Sakoda T., Harada Y., Takei K., Ikeda M., Miyazaki K.

2024 10th International Conference on Condition Monitoring and Diagnosis, CMD 2024 358 - 361 2024年10月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：2024 10th International Conference on Condition Monitoring and Diagnosis, CMD 2024

Partial discharge (PD) and electrical treeing phenomena in an epoxy resin electrode which had two spherical voids and the insulation paper were investigated. The alignment of the two voids was vertical against the applied electric field direction, and experiments with not only two voids of the same size (diameter of 1 mm) but also two voids of different size (diameters of 1 mm and 1.5 mm) were carried out. AC high voltage was applied until the breakdown occurred in the epoxy resin electrode. PD and electrical treeing phenomena were detected by using a high frequency current transformer (HF-CT) sensor, a transient earth voltage (TEV) sensor and an ultra-high frequency (UHF) sensor. We here focused on variations of the number of PDs per unit time and frequency components of detected signals with the elapsed time from the voltage application. As a result, we investigated a unique electrical tree development characteristic which differed in the size of two voids. Although the electrical tree development was temporarily decelerated by the insulation paper, the breakdown suddenly occurred from a point of high electric field in the insulation paper. Additionally, we investigated the temporal variations of the number of PDs which differed in the combination of the void size.

DOI： 10.23919/CMD62064.2024.10766291

Diagnosis of Degradation Degree on SiR Surface Used for Insulator by Surface Discharge 査読あり

Khaing M.T., Miyake T., Sakoda T., Goto S., Anjiki T., Chiba T., Kasuga Y.

2024 10th International Conference on Condition Monitoring and Diagnosis, CMD 2024 386 - 389 2024年10月

担当区分：責任著者掲載種別：研究論文（学術雑誌）出版者・発行元：2024 10th International Conference on Condition Monitoring and Diagnosis, CMD 2024

Silicone rubber (SiR) insulators have been mostly preferred for high-voltage transmission and distribution lines because of their superior hydrophobicity characteristic. Hydrophobicity of SiR insulators may be, however, degraded by multiple stresses and may eventually lead to dry band arcing. Hence, a diagnostic technique of degradation degree on SiR surface will be useful for the long-term maintenance of SiR insulators. In this study, the artificially degraded layers were first made on two SiR surfaces by red clay adhesion, UV irradiation and surface heating. To diagnose the degradation degree on the SiR surface, an unused SiR surface, two artificially degraded SiR surfaces (Sample A (UV, Heating) and Sample B (Heating, UV)) and two aged SiR surfaces (10-year-aged and 20-year-aged) were exposed to a surface discharge (SD) source. The applied voltage and treatment time of SD against the experimental SiR surfaces were 8 kVp-p and 10 s, respectively. After the SD treatment, the hydrophobicity recovery time of each experimental SiR surface was evaluated with the contact angle of a water droplet on the SiR surface. Then, monitoring of water-repellent maintenance (i.e., the contact angle of water droplets on the SiR surface remaining in stable condition) on each experimental SiR surface was also conducted. It was found that the hydrophobicity recovery times and water-repellent change times (duration of contact angle of water droplets on the SiR surface in stable condition) of Sample A (UV, Heating) and Sample B (Heating, UV) were similar to those of 10-year-aged and 20-year-aged SiR surfaces, respectively. Additionally, water-repellent change times of Sample B (Heating, UV) and 20-year-aged SiR surfaces were shorter compared with those of Sample A (UV, Heating) and 10-year-aged SiR surfaces.

DOI： 10.23919/CMD62064.2024.10766183

Characterization of Surface Discharge Used for Measuring Degradation Degree of Polymer Insulator 査読あり

Khaing M.T., Miyake T., Sakoda T.

Proceedings of the IEEE International Conference on Properties and Applications of Dielectric Materials 254 - 257 2024年8月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Proceedings of the IEEE International Conference on Properties and Applications of Dielectric Materials

Polymer insulators with silicone rubber (SiR) insulation have unique properties and are installed all over the world. However, due to pollution deposits on the surface, the characteristics of polymer insulators become degraded. We have already investigated that the degradation degree of the polymer insulator can be evaluated by a 20-cycle salt-fog aging test or a surface discharge (SD) treatment. However, the decrease mechanism of the contact angle by such discharge treatment wasn't interpreted in detail. In this study, to characterize SD generated on the surfaces of SiR, we first measured the SD current. The observed maximum SD current did not significantly differ from that obtained during the 20-cycle-salt-fog aging test. In addition, the SD consisted of filamentary discharges. In measurements of optical emissions, emissions with wavelengths of less than 291 nm which can cut C-H bond of SiR weren't observed. Therefore, it is thought that the direct energy transfer from energetic particles with higher energy than the binding energy of C-H changes chemical characteristics and decreases the contact angle on the SiR surface.

DOI： 10.1109/ICPADM61663.2024.10750781

Partial Discharge Behavior Prior to Breakdown in Epoxy Resin 査読あり

Htet S.Z.L., Kondo T., Miyake T., Sakoda T., Nishimura T.

IEEJ Transactions on Electrical and Electronic Engineering 19 ( 12 ) 1927 - 1935 2024年7月

担当区分：責任著者掲載種別：研究論文（学術雑誌）出版者・発行元：IEEJ Transactions on Electrical and Electronic Engineering

To evaluate the deterioration degree of insulation material by monitoring partial discharges (PDs), it is necessary to fully understand the PD behavior prior to breakdown. We performed measurements of temporal variations in the number and magnitude of PDs in a void of epoxy resin. It was found that the number of PDs with larger magnitude is less before breakdown and that there is a decreased tendency of the number and magnitude of PDs with the elapsed time. The tendency is remarkable as the applied electric field is small. Additionally, the time to breakdown becomes short when the scattering of the number of PDs per unit time decreases. © 2024 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC.

DOI： 10.1002/tee.24160

Voltage and Current Characteristics of Schottky Barrier Diodes and Rectifier Diodes Exposed to Standard Lightning Impulse Voltage 査読あり

Ko T.Z.W., Torihara R., Sakoda T., Hayashi N.

IEEJ Transactions on Electrical and Electronic Engineering 19 ( 6 ) 1105 - 1112 2024年6月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEJ Transactions on Electrical and Electronic Engineering

Lightning surges are one of the major reasons of bypass diode (BPD) failure in photovoltaic modules. In this study, standard lightning impulse voltages (SLIVs) were directly applied to Schottky barrier diodes (SKB diodes) and rectifier diodes (PNJ diodes) with different electrical specifications. The critical voltages Vc of SLIV at which the diodes were damaged and the temporal variations of diode current (iD) and voltage (vD) were measured. It was found the iD-vD characteristics can be categorized into a total of eight patterns: four patterns for the forward SLIV application and the four for the reverse SLIV application, regardless of diode types. The measured results imply that the irreversible voltage dip that occurs before the termination of the reverse breakdown contributes significantly to diode damage in the both forward and reverse SLIV applications. SKB diodes exposed to the reverse SLIV are easily damaged at the lowest magnitude of SLIV among all combinations of diode types and SLIV directions. Once a diode has been damaged due to the first SLIV application, the second application of SLIV to the same diode causes remarkable change in the iD-vD characteristic even if the magnitude of the second SLIV is smaller than Vc. © 2024 Institute of Electrical Engineer of Japan and Wiley Periodicals LLC.

DOI： 10.1002/tee.24064

Short-time Fabrication of Degraded Surface on Silicone Rubber Used for Insulators 査読あり

Khaing M.T., Yoshimura K., Miyake T., Sakoda T., Goto S., Anjiki T., Chiba T., Kasuga Y.

IEEE Transactions on Dielectrics and Electrical Insulation 31 ( 2 ) 1054 - 1061 2024年4月

掲載種別：研究論文（学術雑誌）出版者・発行元：IEEE Transactions on Dielectrics and Electrical Insulation

Silicone rubber (SiR) insulators are degraded due to multiple stresses. To develop a degradation diagnostic technique, a lot of aged insulators are required. However, collecting a lot of several decades of used SiR insulators is difficult. Therefore, it is desired to fabricate the degraded SiR surface whose characteristics are similar to those of degraded SiR insulators in outdoor. To grasp characteristics of the degraded SiR surface, we first investigated characteristics of aged SiR insulators. Foreign matters on aged SiR specimens made the contact angle larger, and Si-O, Si-CH<sub>3</sub>, C-H, and O-H bonds decreased. Next, to fabricate the artificially degraded SiR surface, we proposed a 24 h – fabrication - cycle which consists of a red clay adhesion process, a UV irradiation process, a surface heating process, a heat radiation process, and a surface cleaning process. We evaluated effects of the UV irradiation and the surface heating, and then it was found that a combination of UV irradiation for breaking molecular structure and surface heating for promoting LMW dispersion played an important role in adhering red clay to SiR. The contact angle and the chemical structure on the artificially degraded SiR surface, which was fabricated by UV irradiation for 6 h and surface heating at 20°C or 40°C, were similar to those of a SiR specimen aged 10 years with the hydrophobicity of HC 2.

DOI： 10.1109/TDEI.2023.3329789

Evaluation of degradation degree of artificially degraded silicone rubber surface by using surface discharge 査読あり

Khaing M.T., Miyake T., Sakoda T., Kanenari U., Nishihiro Y.

Journal of Electrostatics 128 2024年3月

掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Electrostatics

To establish an evaluation technique of the degradation degree of silicone rubber (SiR) surfaces, we first fabricated artificially degraded SiR surfaces. The fabrication process consisted of 5 steps and a 1-cycle test required 24 h. We fabricated the degraded SiR surfaces by a 1-cycle or a 2-cycle test. Next, the artificially degraded SiR surface was exposed to surface discharge (SD). The hydrophobicity recovery time on artificially degraded SiR surface increased with the increase in SD treatment time. It was found that the degradation degree of the SiR surface can be evaluated by hydrophobicity recovery time after SD treatment.

DOI： 10.1016/j.elstat.2024.103898

Characteristics of Aged Silicone Rubber Insulators Used in Outdoor for 20 Years 査読あり

May Thin Khaing, Kosei Yoshimura, Takuma Miyake, Tatsuya Sakoda, Uki Kanenari, Yusuke Nishihiro

IEEJ Transactions on Electrical and Electronic Engineering 19 ( 4 ) 454 - 460 2024年1月

担当区分：最終著者記述言語：英語掲載種別：研究論文（学術雑誌）

Degradation Monitoring of Silicone Rubber Used for Insulators 査読あり

May Thin Khaing, Kosei Yoshimura, Takuma Miyake, Tatsuya Sakoda, Shigehiko Goto, Tomikazu Anjiki, Tomoki Chiba, and Yasunori Kasuga

23rd Int. Symposium on High Voltage Engineering (ISH) 866 - 870 2023年8月

担当区分：最終著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Formation of Degradation Layer on Silicone Rubber Used for Insulators 査読あり

Khaing M.T., Yoshimura K., Sakoda T., Goto S., Anjiki T., Chiba T., Kasuga Y.

2023 IEEE Electrical Insulation Conference, EIC 2023 2023年6月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：2023 IEEE Electrical Insulation Conference, EIC 2023

Silicone rubber (SiR) insulators have been increasingly used for transmission and distribution systems. However, it is concerned that performance and property of SiR insulator in operation are degraded due to multiple stresses. We now aim to develop a diagnosis technique of degradation degree of SiR insulator exposed to the multiple stresses. In order to investigate the degradation characteristics and establish the diagnosis technique, aged specimens are required. However, it is difficult to collect a lot of aged SiR insulators used for more than several decades. Therefore, we tried to fabricate the artificial degradation surface, which is similar to ones obtained from actual fields. To analyze the surface degradation of actually aged SiR insulators, hydrophobicity class (HC) of 22kV-SiR insulators arranged for 10 and 20 years in coastal areas was first evaluated. Next, considering the multiple stresses, the degradation surface was fabricated by red clay, UV ray irradiation and surface heating. Aged SiR specimens and artificially degraded SiR spmecimens were characterized by using a contact angle meter, a scanning electron microscopy (SEM), and an attenuated total reflectance-Fourier transform infrared spectrometer (ATR-FTIR). The hydrophobicity of artificially degraded SiR specimen can be decreased due to red clay adhesion/ surface pollution on its surface as the similar condition as actually aged SiR specimen. It was also found that Si-O bond, Si-CH3 bond and C-H bond can be controlled by UV irradiation and the heating temperature.

DOI： 10.1109/EIC55835.2023.10177357

Influence of Electric Field and Fillers on Electrical Tree Development in Epoxy Resin 査読あり

Kawaguchi T., Sakoda T., Nishimura T.

IEEJ Transactions on Fundamentals and Materials 143 ( 2 ) 46 - 53 2023年2月

担当区分：責任著者記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEJ Transactions on Fundamentals and Materials

We investigate the influence of electric field in a void of epoxy resin with fillers on development of electrical trees. Not only observations of pits and electrical trees but also measurements of temporal variations of the number of partial discharges (PDs) and the PD magnitude were carried out. It was found that PDs with several hundred pC can be measurement by a CT sensor until the obvious formation of an electric tree is achieved in the case of epoxy resin without fillers. Additionally, when electric field of the tip of a pit is the almost same as the withstand electric field of the epoxy resin, electrical tree and breakdown occur in a very short time. The development of electrical tree is disturbed by fillers in epoxy resin, and the required time for breakdown is much longer than that of epoxy resin without fillers.

DOI： 10.1541/ieejfms.143.46

Influence of impulse corona discharge on discharge time lag of a surge arrester with a spark gap 査読あり

Sakoda T., Kubo K., Mizutani M., Chiba T., Kasuga Y., Fukano T.

Journal of Electrostatics 121 2023年1月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Electrostatics

ZnO surge arrester with a spark gap is used for reducing electrical failures in power distribution systems of Japan. The high responsiveness, the low residual voltage, and the stable operating voltage are required for the arresters. However, the discharge time lag generally occurs in a spark gap. In this study, measurements of V-t characteristics and observations of optical emissions from impulse corona discharges generated at a newly designed small step edge on an inclined plane of each electrode were carried out. The small step edge made the discharge time lag and the standard deviation small. Based on the results, we indicated that the impulse corona discharge improves the discharge time lag of the sparkover.

DOI： 10.1016/j.elstat.2022.103783

Short-time Evaluation Technique of Degradation Degree by Surface Discharge 査読あり

Khaing M.T., Yoshimura K., Sakoda T., Goto S., Anjiki T., Chiba T., Kasuga Y.

IET Conference Proceedings 2023 ( 46 ) 992 - 996 2023年

掲載種別：研究論文（学術雑誌）出版者・発行元：IET Conference Proceedings

Silicone rubber (SiR) is being adopted as the housing material for insulators. However, the hydrophobic property and the recovery characteristic might be degraded under multiple stress. As one of the degradation diagnosis techniques for the long-term reliability evaluation of SiR, we have proposed a continuous salt fog test in which 20 - times salt fog aging tests by applying ac voltage for 3 h were repeatedly carried out. However, it takes a much longer time. In this study, we examined a novel technique by using surface discharges (SDs) instead of the previous technique. The SDs were generated on the aged SiR surface for 10 s, and then the hydrophobicity recovery time obtained by measuring the contact angle of a water droplet on the SiR was evaluated. The results indicate a possibility that the hydrophobicity recovery time after the SD treatment can refer to the degradation degree of SiR without causing physical and chemical damage.

DOI： 10.1049/icp.2024.0737

Effect of Supercapacitor on Transient Response of Thermoelectric Generation Systems 査読あり

鳥原亮, 迫田達也, 林則行

宮崎大学工学部紀要 51 69 - 77 2022年11月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：宮崎大学工学部

Thermoelectric generators (TEGs) are being used for the harvesting of wasted thermal energy because the TEG converts the temperature difference into the electrical energy. The purpose of this research is to investigate the transient response of electrical properties for TEG systems when the electric load is connected to them. In this study, two kinds of TEG systems were employed; one installed with only a single thermoelectric module (TEM), and another installed with four TEMs and two DC/DC converters (one converter is to track the MPP of the TEMs, and another converter is to regulate the output voltage). An electric double layer capacitor (EDLC) also called a supercapacitor unit was used to improve the transient performance of the two kinds of TEG systems. A filament electric lamp with a non-linear nature of its resistance was employed to investigate the transient responses of the two TEG systems.
Based on the experimental results, the electrical characteristics (voltage, current and power) are studied, and the transient responses of voltage and current as a function of time are analyzed, and the effect of installing the EDLC to the TEG systems are discussed. It is found that the TEG with only a single TEM has high transient responses of voltage and current, large TEG voltage drop during the transient period. Installation of EDLC to the TEG systems can reduce the transient responses of voltage and current and can also reduce TEG voltage drop during the transient period. It is also found that EDLC increases the maximum power at proper load.

油入変圧器診断用TEVセンサの最適配置の検討査読あり

森航, 迫田達也

宮崎大学工学部紀要 51 79 - 81 2022年11月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：宮崎大学工学部

One of insulation deterioration diagnostic techniques of oil-filled transformers is to detect partial discharge (PD) which is a precursory phenomenon of dielectric breakdown.We now focus on a transient earth voltage (TEV) sonsor for measuing the PDs in oil-filled transformers. The radiating electromagnetic waves from a PD source induces the surface current and forms a pulse-like voltage variation on the tank surface of an oil-filled transformer. The TEV sensor mounted on the tank measures the voltage variation. The tank functions as a receiver of electromagnetic waves, and therefore the relative positional relationships between a PD source and a TEV sensor may strongly influence on the measurement accuracy.
We carryied out numerical analyses of the current density, induced by electromagnetic wave on the tank surface of oil-filled transormer, by using he general-purpose physics simulation software COMSOL ultiphysics. Based on the results, we evaluated the optimal arrangement of TEV sensors.

Effect of Supercapacitor on Transient Response of Thermoelectric Generation Systems

Tin Tin Cho, Ryo Torihara, Tatsuya Sakoda, Noriyuki Hayashi

宮崎大学工学部紀要 ( 51 ) 69 - 77 2022年11月

記述言語：英語掲載種別：研究論文（大学，研究機関等紀要）

Degradation Monitoring of Silicone Rubber Used for Insulators 査読あり

May Thin Khaing, Kosei Yoshimura, Tatsuya Sakoda, Junki Oasa, Shoichi Higashiyama, and Yuko Inaoka

9th International Conference on Condition Monitoring and Diagnosis 2022 382 - 386 2022年11月

担当区分：責任著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Development of Detection Technique of Residual-charges by Inductive Current Pulse 査読あり

Nakaguchi R., Sakoda T., Kataoka T., Okamoto D., Tsuiki U., Futagawa K., Satoh H.

IEEJ Transactions on Fundamentals and Materials 142 ( 7 ) 345 - 346 2022年7月

担当区分：責任著者記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEJ Transactions on Fundamentals and Materials

To establish a novel section locating technique of water-tree degraded 22 kV cross - linked polyethylene (XLPE) cable, we measured the injected current pulse with residual - charges due to water trees in a XLPE cable which was used for 27 years and removed after performing residual charge measurement. It was found that the current/voltage pulse injected at a prescribed value of AC voltage may carry residual charges reflecting water tree length.

DOI： 10.1541/ieejfms.142.345

Voltage and Current Characteristics of Schottky Barrier Diodes when Application of Standard Lightning Impulse Voltage Causes Breakdown of Them 査読あり

Tinzar Win ko, May Oo Khin, Ryo Torihara, Tatsuya Sakoda, Noriyuki Hayashi

The International Council on Electrical Engineering Conference 2022 642 - 649 2022年6月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Change in V-I Characteristics of Schottky Barrier Diodes when Application of Standard Lightning Impulse Voltage Causes Breakdown of Them 査読あり

Swezin Linnhtet, May Oo Khin, Ryo Torihara, Tatsuya Sakoda, Noriyuki Hayashi

The International Council on Electrical Engineering Conference 2022 635 - 641 2022年6月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

油入変圧器内の部分放電による弾性波の効果的な測定方法の提案査読あり

森航, 迫田達也, 佐藤正春, 武井勝俊

電気学会論文誌．　Ａ 142 ( 3 ) 124 - 125 2022年3月

担当区分：責任著者記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：一般社団法人電気学会

Based on numerical and experimental analyses of sound pressure distributions owing to partial discharges in oil-immersed transformer, we propose an effective arrangement of acoustic emission sensors. The sensor arrangement at the surface edge of the transformer housing allows us to minimize the required time for diagnosing.

DOI： 10.1541/ieejfms.142.124

On-line PD Monitoring System (PDLOOK) for XLPE Cables 査読あり

Akaiwa S., Miyagawa K., Nakashima T., Sakoda T., Miyake T., Takayama A.

2022 9th International Conference on Condition Monitoring and Diagnosis, CMD 2022 703 - 706 2022年

掲載種別：研究論文（学術雑誌）出版者・発行元：2022 9th International Conference on Condition Monitoring and Diagnosis, CMD 2022

We have developed a continuous remote monitoring system that can monitor partial discharge (PD) trends for a long period of time, which greatly saves the labor in operating. An Edge terminal uploads a signal obtained from the high frequency CT attached to the power cable to a cloud system. In this process, a PD-like signal is effectively discriminated from a large amount of acquired data by using a noise filtering function. The signal data uploaded on the cloud system is PD-judged by AI, and a learning cycle function improves the AI judgment accuracy.

DOI： 10.23919/CMD54214.2022.9991514

Degradation Monitoring of Silicone Rubber Used for Insulators 査読あり

Khaing M.T., Yoshimura K., Sakoda T., Oasa J., Higashiyama S., Inaoka Y.

2022 9th International Conference on Condition Monitoring and Diagnosis, CMD 2022 382 - 386 2022年

掲載種別：研究論文（学術雑誌）出版者・発行元：2022 9th International Conference on Condition Monitoring and Diagnosis, CMD 2022

Electrical insulation equipment such as insulators contributes to reduction of electrical fault owing to overvoltage. Polymeric material such as silicone rubber (SiR) is gradually replacing porcelain. However, in Japan the application of polymeric material is limited because there are concerns about the hydrophobicity degradation and the decrease of insulation performance. Therefore, it is important to investigate not only pollution effect on the insulation performance but also the long-term reliability of polymeric material. Additionally, it is desired to establish an easy diagnostic technique which can grasp the degree of degradation of polymeric material. To evaluate the degradation degree of SiR of insulators arranged for a long period of time in the coastal area, we first characterized the surface of aged SiR specimen cut out from a line post insulator arrange for 20 years in the coastal area by using the attenuated total internal reflection Fourier transform infrared spectroscopy (ATR-FTIR). Next, we repeatedly performed a salt fog aging test against SiR specimens. Then, the surface hydrophobicity and the leakage current were evaluated. From the ATR-FTIR analysis, it was found that the reflectance peaks due to Si-CH3 symmetric bending of aged specimen decreases in comparison with those of unused specimen. The continuous salt fog aging test investigated that a required time for recovering hydrophobicity is a good index for degradation diagnosis because the required times for recovering hydrophobicity of SiR used for 20 years are much longer than that of unused SiR.

DOI： 10.23919/CMD54214.2022.9991539

Sterilization of stem-end rot of mango using dielectric barrier discharge and investigation of sterilization factors 査読あり

Nakakoga Y., Tada Y., Sakoda T., Tazawa K., Ichikawa H.

Electronics and Communications in Japan 104 ( 4 ) 2021年12月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Electronics and Communications in Japan

To develop a sterilization method for controlling post-harvest stem-end rot of mango, we examined to sterilize fungi on peduncle by using the dielectric barrier discharge (DBD). Additionally, to investigate the sterilization factors, we performed sterilization against stem-end rot on agar medium by using the DBD generated in air, argon gas, or oxygen gas. It was found that the DBD can sterilize fungi with high probability. Ultra-violet ray and O3 do not contribute to the sterilization. High energy electrons, and radicals such as O and OH play an essential role for the sterilization.

DOI： 10.1002/ecj.12325

Evaluation of surface degradation of silicone rubber by continuous salt-fog aging test 査読あり

Adachi K., Miyake T., Sakoda T.

IEEJ Transactions on Fundamentals and Materials 141 ( 10 ) 590 - 596 2021年10月

担当区分：責任著者記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEJ Transactions on Fundamentals and Materials

To evaluate the long-term reliability of polymeric material used for housing material of electric power apparatus, we continuously performed a salt-fog aging test against silicone rubber (SiR) specimens cut out from line post insulators arranged for 10 and 20 years in the coastal area. Then, the surface hydrophobicity and the leakage current were evaluated. The results showed that a required time for recovering hydrophobicity and a discharge ignition time until the leakage current is detectable are good indexes for degradation diagnosis. Especially, the required time for recovering hydrophobicity is useful. The required times for recovering hydrophobicity of SiR used for 10 and 20 years were much longer than that of unused SiR.

DOI： 10.1541/ieejfms.141.590

Dynamic I-V Characteristics of Schottky Diodes and PN Junction Diodes When Lightning Impulse Voltage Is Applied on Them 査読あり

迫田達也

宮崎大学工学部紀要 50 105 - 112 2021年9月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：宮崎大学工学部

The purpose of this study is to assist the operation and maintenance of PV systems by studying the resistive conditions of bypass diode used in PV modules and to develop the diagnosis and on-line monitoring system for small and medium scale PV systems. This paper analyzes the breakdown and non-breakdown
characteristics of Schottky diodes and PN Junction diodes by application of various ranges of voltages by Lightning surge simulator (LSS). In this study, we compare and discuss the numerical data of experimental results obtained under variable voltage applications of LSS are compared for both diodes on the resistive
characteristics after breakdown, waveforms of voltage and current and the behaviors of dynamic curves.
An applied voltage, on which the breakdown of diode takes place and dramatic change in I-V characteristics occurs, is called “critical voltage (Vc)”. From the study, it was observed that the magnitude of critical voltage (Vc) of PN junction diodes is higher than that of Schottky diodes in reverse direction although
there is almost the same in forward direction. The authors are also probing that the possibility of more sensitive monitoring and diagnosis system for the resistive bypass diode in PV system based on numerical simulation results. The great difference of Vc is reflected for the dynamic relationship between voltage and current in reverse biasing for both diodes.

Voltage Profi les on HV Distribution Lines with Various Network Confi gurations and Customers 査読あり

迫田達也

宮崎大学工学部紀要 50 95 - 103 2021年9月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：宮崎大学工学部

Electrical power system reliability is a critical issue for utilities and power loss occurred in transmission and distribution network is a must consideration. Electrical distribution system is the largest portion of network in the electrical power system. There is voltage drop on long HV distribution line (D/L) due to heavy load consumption, absent of voltage regulation, as well as poor power factor collection on long HV D/L. Therefore, phase advancing capacitors (Shunt Capacitor, SCs) are installed in parallel with customer loads for voltage improvement and power factor correction. However, these SCs, sometimes, lead to Ferranti effect, especially at the very lightly loaded condition. Moreover, in recent years, the introduction of photovoltaic power generation systems (PV systems) into HV D/L has developed rapidly and may cause the unacceptable voltage variation on HV D/L.
In this study, a virtual 6.6 kV long distance (20 km) HV D/L without PV system supported from Kyushu Electric Power Company (Qden) in Miyazaki branch, is introduced. In this long distance HV D/L, a 20 MVA transformer, three static voltage regulators (SVRs), and 50 customer loads are included. For very lightly loaded condition, the effects of SCs detachment area on the voltage profiles of HV D/L are numerically investigated and discussed. Moreover, the optimal location is proposed to change the suitable SVR for the purpose of upgrading voltage drop in heavy loaded condition.
Then, voltage profiles of different lengths (20.3 km for long and 8.70 km for short) HV D/Ls with PV system installing SCs at customer’s side and different load capacity are discussed. Furthermore, the conditions of flowing line current on HV D/L with PV system for different load locations are explained with phasor diagram. A program based on the Newton Raphson method was coded for the power flow calculation.

Dynamic I-V Characteristics of Schottky Diodes and PN Junction Diodes When Lightning Impulse Voltage Is Applied on Them

May Oo KHIN, Ryo TORIHARA , Tatsuya SAKODA, Noriyuki HAYASHI

Memoirs of faculty of engineering university of miyazaki 50 105 - 112 2021年9月

記述言語：英語掲載種別：研究論文（大学，研究機関等紀要）

Voltage Profiles on HV Distribution Lines with Various Network Configurations and Customers

May Thin KHAING, Tatsuya SAKODA, Noriyuki HAYASHI

Memoirs of faculty of engineering university of miyazaki 50 95 - 104 2021年9月

記述言語：英語掲載種別：研究論文（大学，研究機関等紀要）

誘電体バリア放電によるマンゴーの軸腐病殺菌と殺菌要因の解明に関する研究査読あり

中古賀雄太　多田陽一朗　迫田達也田澤和俊　市川博章

電気学会論文誌A 141 ( 6 ) 385 - 390 2021年6月

担当区分：責任著者記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEJ Transactions on Fundamentals and Materials

To develop a sterilization method for controlling post-harvest stem-end rot of mango, we examined to sterilize fungi on peduncle by using the dielectric barrier discharge (DBD). Additionally, to investigate the sterilization factors, we performed sterilization against stem-end rot on agar medium by using the DBD generated in air, argon gas or oxygen gas. It was found that the DBD can sterilize fungi with high probability. Ultra-violet ray and O3 don't contribute to the sterilization. High energy electrons, and radicals such as O and OH play an essential role for the sterilization.

DOI： 10.1541/ieejfms.141.385

発電状態においてストリング電流の時間変動特性比較に基づいた不具合ストリングの可視化及び検出手法査読あり

鳥原亮, 小玉昂史, 竹之内修, 迫田達也, 林則行

太陽エネルギー 47 ( 3 ) 27 - 36 2021年5月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：一般社団法人日本太陽エネルギー学会

In this paper, we propose a new method to detect defective string(s) in a photovoltaic (PV) array, in which the temporal variation of string current is employed since it is easily measured in generation mode, independently of the scale of photovoltaic systems. Based on the results of experimental works using both a newly-installed and 20-years-old PV systems, it is demonstrated that the amplitude of string current variation corresponds to the voltage-current characteristics of the target string at the operation voltage of power conditioning system. Numerical results using a simple PV array model quantitatively confirm the experimental results. Two parameters are newly proposed to visualize the measured data. It is illustrated that those two parameters are useful to this end, and consequently, make it possible to easily evaluate the conditions of target string such as power loss and cluster loss.

DOI： 10.24632/jses.47.3_27

Influence of defective bypass diodes on electrical and thermal properties of photovoltaic string and array

Torihara R., Latt N.Z., Khin M.O., Lwin Y.M., Sakoda T., Hayashi N.

IEEE Region 10 Annual International Conference, Proceedings/TENCON 2020-November 1007 - 1012 2020年11月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEE Region 10 Annual International Conference, Proceedings/TENCON

The intent of this paper is to analyze the power consumption or heat dissipation of defective bypass diode (BPD) at open circuit (OC) and maximum power point (MPP) load conditions when the BPD turns to have resistive behavior in a photovoltaic (PV) string and array. We also analyze the thermal impact of defective BPD in a PV string under different irradiances and cell temperatures. It was observed that the power consumption of defective BPD largely depends on load condition and the thermal impact is more severe in OC condition. It was also observed that the thermal impact of defective BPD is larger under either high irradiance level for the same cell temperature or lower cell temperature on the same irradiance. This study indicates that it is necessary to monitor the heat dissipation of BPDs and to evaluate the electrical properties of the BPDs to realize the reliable PV systems.

DOI： 10.1109/TENCON50793.2020.9293827

On-line PD System and PD Locator for XLPE Cables

Sakoda T., Yamasaki Y., Nakanose S., Hayashi N., Miyake T., Miyagawa K., Kawano W.

Proceeding - 8th International Conference on Condition Monitoring and Diagnosis, CMD 2020 222 - 225 2020年10月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Proceeding - 8th International Conference on Condition Monitoring and Diagnosis, CMD 2020

We constructed an on-line partial discharge (PD) monitoring system (PDOM) with a CT sensor, an analogue-digital converter, and a tablet PC. A sampling frequency for data acquisition is 100 MHz, and we exchange on-site PD data through a cloud system. We successfully measured PDs in the early stage of insulation deterioration of a cross-linked polyethylene (XLPE) cable in a field site. Additionally, following PD detection by using a PDOM, we can locate a PD position by using a PD locator (PDL) system. By locating a PD, we can estimate the actual PD magnitude considering attenuation factor of a high frequency pulse. We show how the PDL system works on a XLPE cable network with time synchronization between two positions by using an injection current pulse. The locating accuracy of the PDL system is evaluated.

DOI： 10.1109/CMD48350.2020.9287182

On-line PD system and PD Locator for XLPE Cables 査読あり

Tatsuya Sakoda, Noriyuki Hayashi, Yuhei Yamasaki, Soichiro Nakanose, Takuma Miyake, Wataru Kawano, Koji Miyagawa

8th International Conference on Condition Monitoring and Diagnosis 1 - 4 2020年10月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

インパルス放電のV-t 特性に影響を与える因子査読あり

小田浩史, 間壱誠, 迫田達也, 久保克隆, 水谷学, 春日靖宣, 深野孝人

宮崎大学工学部紀要 49 111 - 114 2020年9月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：宮崎大学工学部

Surge arrester with a spark gap has been installed for reducing the electrical failures in distribution systems. The top and the bottom of a ceramic spacer for sustaining an electrode gap contact with electrodes, in which there are triple junction points among the ceramic spacer, the gap electrodes and the atmosphere. Corona discharges formed at around the triple junction points may influence discharge characteristics for a spark gap. Additionally, the charges on the inner surface of the ceramic spacer, which are electrified by corona dischaeges, may act on the discharge characteristics. We measured V-t characteristic and residual voltage after operating a surge arrester with a spark gap. Based on the results, we evaluate affecting factors to V-t characteristics of impulse discharge .

Study on degradation diagnostic method for silicone rubber

Sakoda T., Minami E., Miyake T., Hayashi N., Goto S., Aka Y., Anjiki T., Kasuga Y., Fukano T.

Journal of Electrostatics 107 2020年9月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Electrostatics

To evaluate the degradation degree of silicone rubber (SiR) of electric power apparatus arranged for a long period of time in the coastal area, we repeatedly performed a salt fog aging test against SiR specimens. Then, the surface hydrophobicity and the leakage current were evaluated. The results showed that a required time for recovering hydrophobicity and a discharge ignition time until the leakage current is detectable are good indexes for degradation diagnosis. Especially, the required time for recovering hydrophobicity is useful.

DOI： 10.1016/j.elstat.2020.103479

XLPE ケーブルを用いた部分放電電流の長距離伝搬特性査読あり

山下勝也, 迫田達也

宮崎大学工学部紀要 49 95 - 99 2020年9月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：宮崎大学工学部

The demand of reliable power systems and stability of electrical power supply are quite crucial for all of power companies. On the other hand, power systems installed during the period of high economic growth have been operating for over 30 years in Japan. For transmission and distribution lines, cross-linked polyethylene (XLPE) cable plays an important role in distributing the stable power to customers. Electric failure for the XLPE cable decreases year by year because of progress of manufacturing. However, at joint and terminal sections of the XLPE cable, partial discharges (PDs) occur in defects of insulating materials. The PD generation can occur at any points in the insulation system where electric field strength exceeds a PD inception electric field and can develop until breakdown occurs. That is, PDs which are owing to local electrical stress in the insulation or on the surface of the insulation reflect a kind of sign of insulation deterioration. Therefore, PD measurement is a useful technique of assessing the insulation deterioration of XLPE cables. In this study, the pulse propagation characteristics of a PD on actual 22kV XLPE cables were investigated.

Multivariate Analysis Using R for Various Climatic Effects on the Output Performances of CIGS and Multi-Crystalline Si Photovoltaic Systems Installed in Miyazaki, Japan

太田靖之, 迫田達也

宮崎大学工学部紀要 49 119 - 127 2020年9月

記述言語：英語掲載種別：研究論文（大学，研究機関等紀要）出版者・発行元：宮崎大学工学部

Generally, the performance of a PV system depends not only on its basic technical characteristics but also on the environmental conditions in which they will be set up. Therefore, studying the effects of climatic parameters such as solar irradiance on the plane of array (GPOA), ambient temperature (Ta), relative humidity (RH) and wind speed (νa) on the performance of PV is vital to be able to utilize efficiently solar energy.
The authors have studied the effects of various climatic parameters on the output performances of the two PV systems, 60 kW Copper Indium Gallium Selenide (CIGS) and 50 kW Multi-Crystalline Silicon (MC-Si), which were installed within the campus of University of Miyazaki, Japan. The main objectives of the research are to improve the prediction of the PV systems performance while knowing the climatic parameters of a particular area in which they stand, and also provide a useful dataset for the comparative studies.
The analyses were done by the multiple linear regression analysis (MLR) using the statistical software R. The performances of the two PV systems are in positive proportion to the GPOA and νa, however, as per the values of the slopes of the regression equations, the MC-Si PV system is smaller than the CIGS PV system, attributed to their different module tilt angles and elevations of the PV sites. The performances are in negative proportion to the Ta, but the more sensitivity can be observed in the MC-Si PV system. The RH negatively affected on the MC-Si PV system, although its positive effects can be observed in the CIGS PV system.

電力ケーブルにおける部分放電発生位置標定技術の精度評価査読あり

山下勝也, 迫田達也

宮崎大学工学部紀要 49 91 - 94 2020年9月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：宮崎大学工学部

For transmission and distribution lines, cross-linked polyethylene (XLPE) cable plays an important role in distributing the stable power to customers. Electric failure for the XLPE cable decreases year by year because of progress of manufacturing. However, at joint and terminal sections of the XLPE cable, partial discharges (PDs) occur in defects of insulating materials. The PD is a precursor to dielectric breakdown. Once PD occurs, it continuously erodes insulation material. The demand of reliable power systems is quite crucial for all of power companies, and then it is demanded to develop an on-line PD measurement technique and a monitoring system. In this study, we propose a PD locating system for XLPE cables in operation, in which the propagation velocity of PD current is not required for locating a PD. We first show how the locating system works on a XLPE cable network with time synchronization between two points. Additionally, the locating accuracy of the system is investigated.

誘電体バリア放電を用いたマンゴー軸腐病の殺菌と雰囲気ガスが殺菌に与える影響査読あり

木之下俊輔, 多田陽一朗, 迫田達也, 田澤和俊, 市川博章

宮崎大学工学部紀要 49 115 - 118 2020年9月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：宮崎大学工学部

Apple mango has been a representative product in Miyazaki. However, Stem–end rot of mango is likely to corrupt the fruit during transportation, which may lead to a decrease in the reliability of branded mangoes. Therefore, it is necessary to perform sterilization. So we made a sterilization device with a dielectric barrier discharge source. In order to confirm the usefulness of this device and the factor of stelirization, we performed sterilization against Lasiodiplodia theobromae and mango fruit inoculated with the fungus evaluated.

水トリー劣化したCV ケーブルの部分放電特性に関する研究査読あり

山崎悠平, 山下勝也, 迫田達也

宮崎大学工学部紀要 49 101 - 104 2020年9月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：宮崎大学工学部

Since the aging of electric facilities have become an important issue in Japan, safety of such facilities in operation and ensuring high reliability are highly demanded. It is also necessary for each electric power company to reduce the cost for maintaining, managing, operating, and updating facilities because of the electric power liberalization. For these backgrounds, some sorts of sophisticated technologies for on-line monitoring systems and deterioration diagnosis technologies are needed rapidly in order to avoid any electric failures. Our esearch is to develop partial discharge locator (PDL) which is to locate cable faults by detecting current pulses generated by partial discharges (PDs). This paper presented theoretical analysis of frequency characteristics of a PD pulse on a branch line for PDL adaptability of multiple branch lines by using a simulation software. In addition, as a comparison to the simulation, we also carried out experiments using actual XLPE cables and confirmed the integrity verification of the simulation results. In this paper, we investigated PD characteristics caused by water trees in XLPE cables. It was found out that PDs can be generated by water trees. Therefore, PDL can be used for locating water tree.

ボイド含有エポキシ樹脂製電極による部分放電特性査読あり

小田浩史, 迫田達也, 相島武, 西村豪志

宮崎大学工学部紀要 49 105 - 109 2020年9月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：宮崎大学工学部

In recent years, insulation deterioration due to partial discharges (PDs) of power equipment molded with epoxy resin is concerned. In a solid insulation device molded with an insulator such as an epoxy resin, bubbles may remain in the resin during the manufacturing process, so that void defects sometimes occur. It is important to clarify the behavior of PD inside the defect from the occurrence to the failure from a viewing point of designing a safe and long-life solid insulation molded device. In this study, the PD occurrence probability and the PD ignition time were investigated. Also, the life characteristics of epoxy resin owing to PDs until a breakdown occurs was evaluated.

Study on Location Accuracy of Partial Discharge Locator for Electric Power Cable

Katsuya YAMASHITA, Tatsuya SAKODA

Memoirs of Faculty of Engineering University of Miyazaki 91 - 94 2020年7月

記述言語：日本語掲載種別：研究論文（大学，研究機関等紀要）

Study on Propagation Characteristics of High Frequency Pulse Current in Electric Power Cable

Katsuya YAMASHITA, Tatsuya SAKODA

Memoirs of Faculty of Engineering University of Miyazaki 95 - 100 2020年7月

記述言語：日本語掲載種別：研究論文（大学，研究機関等紀要）

Partial Discharge Characteristics of XLPE Cable with Water Tree

Yuhei YAMASAKI, Katsuya YAMASHITA, Tatsuya SAKODA

Memoirs of Faculty of Engineering University of Miyazaki 101 - 104 2020年7月

記述言語：日本語掲載種別：研究論文（大学，研究機関等紀要）

Characteristics of Partial Discharge in Epoxy Resin with a Void

Hiroshi ODA, Tatsuya SAKODA, Takeru AISHIMA, Takeshi NISHIMURA

Memoirs of Faculty of Engineering University of Miyazaki 105 - 110 2020年7月

記述言語：日本語掲載種別：研究論文（大学，研究機関等紀要）

Affecting Factors to V-t Characteristics of Impulse Discharge

Hiroshi ODA, Issei HAZAMA, Tatsuya SAKODA, Katsutaka KUBO, Manabu MIZUTANI, Yasunori KASUGA, Takato FUKANO

Memoirs of Faculty of Engineering University of Miyazaki 111 - 114 2020年7月

記述言語：日本語掲載種別：研究論文（大学，研究機関等紀要）

Sterilization of Stem-end Rot of Mango using Dielectric Barrier Discharge Source and 　Influence of Operating Gas on sterilization

Shunsuke KINOSHITA, Yoichiro TADA, Tatsuya SAKODA, Kazutoshi TAZAWA, Hiroyuki ICHIKAWA

Memoirs of Faculty of Engineering University of Miyazaki 115 - 118 2020年7月

記述言語：日本語掲載種別：研究論文（大学，研究機関等紀要）

Multivariate Analysis Using R for Various Climatic Effects on the Output Performances of CIGS and Multi-Crystalline Si Photovoltaic Systems Installed in Miyazaki, Japan

Kyaw Myo WIN, Yasuyuki OTA, Kensuke NISHIOKA, Tatsuya SAKODA, Noriyuki HAYASHI

Memoirs of Faculty of Engineering University of Miyazaki 119 - 128 2020年7月

記述言語：英語掲載種別：研究論文（大学，研究機関等紀要）

Study on degradation diagnostic method for silicone rubber 査読あり

Tatsuya Sakoda, Eisuke Minami, Takuma Miyake, Noriyuki Hayashi, Shigehiko Goto, Yoshiaki Aka, Tomikazu Anjiki, Yasunori Kasuga, Takato Fukano

Journal of Electrostatics 107 103479-1 - 103479-6 2020年6月

記述言語：英語掲載種別：研究論文（学術雑誌）

ケーブルにおける部分放電の位置標定技術査読あり

山下勝也，三宅琢磨，迫田達也，川野渉, 宮川浩二

電気設備学会論文誌 40 ( 4 ) 14 - 19 2020年4月

記述言語：日本語掲載種別：研究論文（学術雑誌）

架橋ポリエチレンケーブルの防蟻層の遮水効果査読あり

黒岩拓真, 迫田達也, 有元慎太郎, 生田昌輝

電気設備学会論文誌 40 ( 3 ) 12 - 13 2020年3月

記述言語：日本語掲載種別：研究論文（学術雑誌）

分岐線路における部分放電電流パルスの伝搬特性査読あり

山下勝也, 三宅琢磨, 迫田　達也, 川野渉

電気学会論文誌A 140 ( 2 ) 92 - 97 2020年2月

記述言語：日本語掲載種別：研究論文（学術雑誌）

架橋ポリエチレンケーブルの防蟻層の遮水効果

黒岩拓真, 迫田達也, 有元慎太郎, 生田昌輝

電気設備学会論文誌 40 ( 3 ) 12 - 13 2020年

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：一般社団法人電気設備学会

Water-tree degradation of underground cross-linked polyethylene (XLPE) cables has been concerned. However, it seems that there is no reports of water-trees for XLPE cables with the termite preventive layer. We focus on investigation of a water shielding effect due to the termite preventive layer of the XLPE cable. The results showed that the water absorption rate of the insulting vinyl sheath was 3.18 times higher than that of a termite preventive layer at 70℃. Thus, the high - water shielding effect of XLPE cable with the termite preventive layer was confirmed.

DOI： 10.14936/tieiej.40.3_12

Propagation characteristics of partial discharge current pulse for branched line

Yamashita K., Miyake T., Sakoda T., Kawano W.

IEEJ Transactions on Fundamentals and Materials 140 ( 2 ) 92 - 97 2020年

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEJ Transactions on Fundamentals and Materials

At joint and terminal sections of electric power cables, there is possibility to occur partial discharges (PDs) in defects of insulating materials. Therefore, PD measurement is useful from a viewpoint of assessing insulation deterioration of electric power cables. There are some measurement systems to locate PDs, however, it is quite difficult and complicated in the case where cable lines include branched lines because the PD current pulse separately flows at the branch line. To establish a PD location system, the investigation of propagation characteristics of PD current pulse for branched lines is necessary. Based on EMTP simulations and experiments, we evaluated how a PD current pulse propagates at a Y-branch. The results showed that the separation of a PD current pulse is dependent on frequency component of the PD current pulse and the cable impedance after branching. The frequency components of a PD current pulse, which are higher than the resonant frequency of lines, tend to flow into the longer cable side.

DOI： 10.1541/ieejfms.140.92

GPSを活用したXLPEケーブルにおける部分放電の位置標定技術

山下勝也, 三宅琢磨, 迫田達也, 川野渉, 宮川浩二

電気設備学会論文誌 40 ( 4 ) 14 - 19 2020年

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：一般社団法人電気設備学会

For transmission and distribution lines, cross-linked polyethylene (XLPE) cable plays an important role in distributing the stable power to customers. Electric failure for the XLPE cable decreases year by year because of progress of manufacturing. However, at joint and terminal sections of the XLPE cable, partial discharges (PDs) occur in defects of insulating materials. The PD is a precursor to dielectric breakdown. Once PD occurs, it continuously erodes insulation material. The demand of reliable power systems is quite crucial for all of power companies, and then it is demanded to develop an on-line PD measurement technique and a monitoring system.
In this study, we propose a PD locating system for XLPE cables in operation, in which the propagation velocity of PD current is not required for locating a PD. We first show how the locating system works on a XLPE cable network with time synchronization between two points. Additionally, the locating accuracy of the system is investigated.

DOI： 10.14936/tieiej.40.4_14

マンゴー軸腐病の防除手法の検討

多田陽一朗,木之下俊輔,迫田達也,田澤和俊,市川博章

放電・プラズマ・パルスパワー研究会・放電・プラズマ・パルスパワー 2019年10月

記述言語：日本語掲載種別：研究論文（研究会，シンポジウム資料等）

部分放電電流の分岐伝搬特性に関する基礎的検討

山下勝也, 山﨑悠平, 三宅琢磨, 迫田達也, 川野渉

放電・プラズマ・パルスパワー研究会・放電・プラズマ・パルスパワー 2019年10月

記述言語：日本語掲載種別：研究論文（研究会，シンポジウム資料等）

Electrical characteristics of artificially polluted silicone rubber 査読あり

TAKEZAKI Kento, MIYAKE Takuma, SAKODA Tatsuya, GOTO Shigehiko, AKA Yoshiaki, and ANJIKI Tomikazu

The International Council on Electrical Engineering (ICEE) Conference 2019年7月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Propagation Characteristics of Partial Discharge Pulse Current on Branched Line

Katsuya YAMASHITA, Takuma MIYAKE, Tatsuya SAKODA, Wataru KAWANO

MEMOIRS OF FACULTY OF ENGINEERING UNIVERSITY OF MIYAZAKI 99 - 102 2019年7月

記述言語：日本語掲載種別：研究論文（大学，研究機関等紀要）

Sterilization of Bacillus Subtilis and measurement of O3 concentration in sterilization device using dielectric barrier discharge

Junichiro TSUCHIDA, Shunsuke KINOSHITA, Tatsuya SAKODA

MEMOIRS OF FACULTY OF ENGINEERING UNIVERSITY OF MIYAZAKI 95 - 98 2019年7月

記述言語：日本語掲載種別：研究論文（大学，研究機関等紀要）

Sterilization of Stem-end rot of Mango using a dielectric barrier discharge source

Shunsuke KINOSHITA, Junichiro TSUCHIDA, Tatsuya SAKODA, Kazutoshi TAZAWA, Hiroaki ICHIKAWA

MEMOIRS OF FACULTY OF ENGINEERING UNIVERSITY OF MIYAZAKI 2019年7月

記述言語：日本語掲載種別：研究論文（大学，研究機関等紀要）

Study on Location Accuracy of Partial Discharge Locator 査読あり

Katsuya Yamashita, Takuma Miyake, Tatsuya Sakoda, Wataru Kawano

2019 Electrical Insulation Conference 321 - 324 2019年6月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Material Temperature Dependence on Behavior of Partial Discharge in Epoxy Resin 査読あり

Tatsuya Sakoda, Mitsuki Kawakone, Noriyuki Hayshi, Makoto Setoguchi, Makoto Setoguchi

2019 Electrical Insulation Conference 205 - 208 2019年6月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

誘電体バリア放電を用いたマンゴー軸腐病の発病抑制効果査読あり

土田潤一郎, 迫田達也, 田澤和俊, 市川博章, 溝口則和, 櫛間義幸

電気学会論文誌Ａ 139 ( 5 ) 279 - 280 2019年5月

記述言語：日本語掲載種別：研究論文（学術雑誌）

Characteristics of underwater plasma with surfactant 査読あり

Hiroki Goto and Tatsuya Sakoda

Electrical Engineering Japan 1 - 7 2018年10月

記述言語：英語掲載種別：研究論文（学術雑誌）

Long-Term Observation of Ambient Temperature Effects on the Performance of A 60 kW CIGS Solar Power System Installed in Miyazaki 査読あり

Kyaw Myo Win, Ryo Torihara, Shohei Kita, Tetsuya Sakoda, Yasuyuki Ota, Kensuke Nishioka, and Noriyuki Hayashi

Proceedings of TENCON 2018 - 2018 IEEE Region 10 Conference 2018年10月

記述言語：英語掲載種別：研究論文（学術雑誌）

Examination of Compact and Online Diagnosis Method Based on Temporal Fluctuation of String Currents of Photovoltaic Solar Plant 査読あり

Ryo Torihara, Shohei Kita, Osamu Takenouchi, Tetsuya Sakoda, and Noriyuki Hayashi

Proceedings of TENCON 2018 - 2018 IEEE Region 10 Conference 2018年10月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

配電用ギャップ付酸化亜鉛形避雷器の放電遅れ現象に関する研究査読あり

迫田達也, 堀江響, 武居周, 久保克隆, 水谷学, 深野孝人

電気学会論文誌A 138 ( ９ ) 457 - 462 2018年9月

記述言語：日本語掲載種別：研究論文（学術雑誌）

界面活性剤添加時の水中プラズマ源の特性査読あり

後藤弘輝, 迫田達也

電気学会論文誌 A 138 ( 7 ) 355 - 360 2018年7月

記述言語：日本語掲載種別：研究論文（学術雑誌）

CVT ケーブルの劣化位置標定に関する基礎研究

池田佑允, 迫田達也, 佐藤英章, 春山浩, 宮崎和則

宮崎大学工学部紀要 47 143 - 148 2018年7月

記述言語：日本語掲載種別：研究論文（大学，研究機関等紀要）

塩分濃度を変化させた場合のポリマー材料の耐電圧評価

川口翔大, 迫田達也, 阿嘉良昌, 安食富和, 深野孝人

宮崎大学工学部紀要 47 149 - 152 2018年7月

記述言語：日本語掲載種別：研究論文（大学，研究機関等紀要）

界面活性剤添加時における水中プラズマ源の特性の検討

後藤弘輝, 西村豪志, 土田潤一郎, 迫田達也

宮崎大学工学部紀 47 157 - 162 2018年7月

記述言語：日本語掲載種別：研究論文（大学，研究機関等紀要）

変成器内部で生じる部分放電放射電磁波の周波数特性

川小根光輝, 白浜優吾, 中村友哉, 迫田達也

宮崎大学工学部紀要 47 153 - 156 2018年7月

記述言語：日本語掲載種別：研究論文（大学，研究機関等紀要）

配電機器内部で生じた部分放電による放射電磁波特性

白浜優吾, 中村友哉, 川小根光輝, 迫田達也

宮崎大学工学部紀要 47 163 - 166 2018年7月

記述言語：日本語掲載種別：研究論文（大学，研究機関等紀要）

シリコーンゴムの塩害に対する耐汚損特性の検討

田平耕成, 迫田達也, 阿嘉良昌, 安食富和, 深野孝人

宮崎大学工学部紀要 47 167 - 170 2018年7月

記述言語：日本語掲載種別：研究論文（大学，研究機関等紀要）

Heガスを利用したプラズマ装置における遷移発光強度の測定と芽胞菌の殺菌

土田潤一郎, 西村豪志, 後藤弘輝, 迫田達也

宮崎大学工学部紀要 47 171 - 174 2018年7月

記述言語：日本語掲載種別：研究論文（大学，研究機関等紀要）

塩霧試験におけるポリマー材料の撥水性特性の評価

南英佑, 迫田達也, 阿嘉良昌, 安食富和, 深野孝人

宮崎大学工学部紀要 47 183 - 186 2018年7月

記述言語：日本語掲載種別：研究論文（大学，研究機関等紀要）

プラグインエルボで発生する沿面放電特性

中村友哉, 川小根光輝, 白浜優吾, 迫田達也

宮崎大学工学部紀要 47 175 - 178 2018年7月

記述言語：日本語掲載種別：研究論文（大学，研究機関等紀要）

誘電体バリア放電を利用した殺菌装置における芽胞菌の殺菌

西村豪志, 土田潤一郎, 迫田達也

宮崎大学工学部紀要 47 179 - 182 2018年7月

記述言語：日本語掲載種別：研究論文（大学，研究機関等紀要）

配電用直列ギャップ付酸化亜鉛形避雷器のV -t 特性の改善に関する研究

堀江響, 迫田達也, 久保克隆, 水谷学, 深野孝人

宮崎大学工学部紀要 47 187 - 192 2018年7月

記述言語：日本語掲載種別：研究論文（大学，研究機関等紀要）

Control of Voltage Rise Caused by the Reversed Power Flow in High Voltage Distribution System by Detaching Shunt Capacitors and Optimum Location of PV Power Plan 査読あり

Thin Thin Hlaing, Tatsuya Sakoda, and Noriyuki Hayashi

24th International Conference on Electrical Engineering 178 - 184 2018年6月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Comarative Analysis of Optimization Based Tuning Method and Conventional Tuning Method for LFC of Multi-Area Power System 査読あり

Aung Ko Latt, Tatsuya Sakoda, and Noriyuki Hayashi

24th International Conference on Electrical Engineering 228 - 234 2018年6月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Development of on-line partial discharge locator for electric power cable 査読あり

Katsuya Yamashita, Souta Watanuki, Takuma Miyake, Tatsuya Sakoda, Wataru Kawano

2018 Electrical Insulation Conference (EIC) 216 - 219 2018年6月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Variation in Insulation Performance of Artificially Polluted Silicone Rubber 査読あり

Kento Takezaki, Takuma Miyake, Tatsuya Sakoda, Yoshiaki Aka, Tomikazu Anjiki, Takato Fukano

24th International Conference on Electrical Engineering 1679 - 1684 2018年6月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Discharge behavior and dielectric performance of artificially polluted hydrophobic silicone rubber 査読あり

Sakoda T., Tabira K., Miyake T., Hayashi N., Haji K., Aka Y., Anjiki T., Fukano T.

Journal of Electrostatics 93 97 - 103 2018年6月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Electrostatics

© 2018 Flashover voltage and discharges behavior were investigated with silicone rubber (SiR) polluted with fog, red clay or carbon particles. For a SiR polluted with carbon, partial discharges occur between water droplets and form interspersed dry bands. For a SiR polluted with red clay, the leakage current induces uniform dry bands and dry-band arc discharges. Because flashover occurs through the dry bands, the noticeable difference in flashover voltage between the polluting materials is not seen. The pollution deposit changes the surface state and causes partial discharges which lead large leakage current, however, the partial discharges don't significantly lower insulation performance.

DOI： 10.1016/j.elstat.2018.04.006

Recovery characteristics of hydrophobicity and electrical property of polymeric material 査読あり

Minami E., Miyake T., Sakoda T., Aka Y., Anjiki T., Fukano T.

IEEJ Transactions on Fundamentals and Materials 138 ( 3 ) 115 - 116 2018年3月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEJ Transactions on Fundamentals and Materials

© 2018 The Institute of Electrical Engineers of Japan. To evaluate the long-term reliability of polymeric material used for electric power apparatus in the coastal area and to establish its insulation diagnosis technique, we evaluated recovery characteristics of hydrophobicity and electrical property of silicone rubber (SiR) by performing a salt fog aging test. As the result, the required times for recovery between the hydrophobicity and the electrical property are different. The time when the leakage current begins to be detectable might be a good index of the deterioration diagnosis.

DOI： 10.1541/ieejfms.138.115

Numerical analysis of I-V characteristics and diode currents of a PV module reflected by partial shadow

Numerical analysis of electrical characteristics of a PV module irradiated by an impulse light flash 査読あり

Cheikh Ibra Wade, Ryo Torihara, Tatsuya Sakoda and Noriyuki Hayashi

Journal of InternatIonal Council on Electrical Engineering, Vol. 8, No. 1, pp. 8-13 (2018.2) 1 ( 8 ) 8 - 13 2018年2月

記述言語：英語掲載種別：研究論文（学術雑誌）

熱電発電システムにおいて各モジュール間の内部抵抗の違いを考慮した最大出力点追尾の制御手法査読あり

奥将俊, 田島大輔, 迫田達也, 林則行, 穂高一条

太陽エネルギー 1 ( 44 ) 79 - 87 2018年1月

記述言語：日本語掲載種別：研究論文（学術雑誌）

Improvement of Discharge Ignition Characteristics of a Surge Arrester with a Spark Gap 査読あり

Hibiki Horie, Tatsuya Sakoda, Katsutaka Kubo, Manabu Mizutani, Takato Fukano

IEEJ Transactions on Fundamentals and Materials 11 ( 137 ) 724 - 729 2017年11月

記述言語：英語掲載種別：研究論文（学術雑誌）

デシカント空調システムにおける外気の絶対湿度とシステム運転方式との関係

石川敏嗣，藤澤一平，迫田達也，林則之

宮崎大学工学部紀要 46 179 - 184 2017年7月

記述言語：日本語掲載種別：研究論文（大学，研究機関等紀要）

マンゴーに発生する病害の防除を目指したプラズマミスと装置における芽胞菌及び大腸菌の殺菌

西村豪志, 堂園大雅, 後藤弘輝, 富永大, 迫田達也

宮崎大学工学部紀要 46 175 - 178 2017年7月

記述言語：日本語掲載種別：研究論文（大学，研究機関等紀要）

真空遮断器を対象とした部分放電検知の劣化診断技術の開発

朝倉匡俊, 岸本恵修, 三宅琢磨, 迫田達也, 壱岐祐典, 前田健作

宮崎大学工学部紀要 46 133 - 138 2017年7月

記述言語：日本語掲載種別：研究論文（大学，研究機関等紀要）

絶縁体内部で発生する部分放電の劣化特性

平島俊紀，中村友哉，白浜優吾，迫田達也

宮崎大学工学部紀要 46 139 - 142 2017年7月

記述言語：日本語掲載種別：研究論文（大学，研究機関等紀要）

電磁波センサを用いた配電機器内部で生じる部分放電の検出

白浜優吾，平島俊紀，中村友哉，迫田達也

宮崎大学工学部紀要 46 139 - 142 2017年7月

記述言語：日本語掲載種別：研究論文（大学，研究機関等紀要）

交流課電によるポリマー材料の耐電圧特性評価

出口竜也, 迫田達也, 阿嘉義昌, 安食富和, 深野孝人

宮崎大学工学部紀要 46 159 - 163 2017年7月

記述言語：日本語掲載種別：研究論文（大学，研究機関等紀要）

直列ギャップ付ZnO避雷器のV-t特性の改善に関する研究

堀江響, 迫田達也, 久保克隆, 水谷学, 深野孝人

宮崎大学工学部紀要 46 155 - 158 2017年7月

記述言語：日本語掲載種別：研究論文（大学，研究機関等紀要）

Numerical Analysis of Electrical Characteristics of a PV Module Irradiated by an Impulse Light Flash 査読あり

CHEIKH IBRA WADE, RYO TORIHARA, TATSUYA SAKODA, NORIYUKI HAYASHI

The International Conference on Electrical Engineering 1 - 4 2017年6月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Study on Grasping Partial Discharge Development Using an Acoustic Emission Technique 査読あり

Tatsuya Sakoda, Toshiki Hirashima, Tomoya Nakamura, Yugo Shirahama, Noriyuki Hayashi

The Journal of CPRI 16 ( 3 ) 1 - 6 2017年3月

記述言語：英語掲載種別：研究論文（学術雑誌）

Wade C., Torihara R., Fukamachi Y., Sakoda T., Hayashi N.

IEEE Region 10 Annual International Conference, Proceedings/TENCON 2642 - 2645 2017年2月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEE Region 10 Annual International Conference, Proceedings/TENCON

© 2016 IEEE. The authors have studied the diagnosis method of PV systems. In this paper, influences of partial shadow reflected partly on PV panels on the electrical characteristics of solar cells are numerically investigated by using the LT Spice simulation. Not only the change in I-V characteristics, but also the change in current and voltage distribution for every cell component are demonstrated and discussed based on the numerical results. It is clearly illustrated that the cell with the lowest transmission of sunlight among the cells concerned dominates the whole characteristics of the PV module. Numerical results obtained from the current simulation will provide basic knowledge when estimating the total I-V characteristics of a whole PV system which composed of multiple PV subsystems having different I-V characteristics with each other.

DOI： 10.1109/TENCON.2016.7848517

Improvement of discharge ignition characteristics of a surge arrester with a spark gap

Horie H., Sakoda T., Kubo K., Mizutani M., Fukano T.

IEEJ Transactions on Power and Energy 137 ( 11 ) 724 - 729 2017年

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEJ Transactions on Power and Energy

© 2017 The Institute of Electrical Engineers of Japan. Surge arrester with a spark gap has been installed for reducing electrical failures in Japanese distribution system. The top and the bottom of a ceramic spacer for sustaining an electrode gap in a surge arrester contact with electrodes, of which the electric field becomes high. Therefore, high electric field region such as the triple junction point becomes a source to supply electrons to a spark-gap. In this study, we made some electrodes with a small step edge on an inclined plane of an electrode. The electric field around the small step edge became high, and we aimed that the small step edge functioned as if it were a triple junction points for a conventional spark gap. Based on measurements of V-t characteristic and the number of electrons per unit time, we investigated that the artificially formed high electric field region lower impulse spark-over voltage and that a spark-over voltage occurs within a duration of 0.4-1.2 μs when a positive impulse voltage of 25-42 kV with 1.2/50 μs is applied. The results will contribute on a further stabilization of discharge and increasing a degree of freedom for design of a spark gap.

DOI： 10.1541/ieejpes.137.724

Chemical Analysis of Casual Elements for Deterioration of Cylindrical EDLC

Yoshitama H., Tashima D., Sakoda T., Hayashi N., Yuhara M., Utsunomiya T.

Electronics and Communications in Japan 99 ( 12 ) 36 - 43 2016年12月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Electronics and Communications in Japan

© 2016 Wiley Periodicals, Inc. Chemical analysis was carried out before and after the constant voltage hold test that was an acceleration deterioration examination to clarify deterioration factors of electric double-layer capacitor (EDLC). The results showed that the stress test slightly caused the increase of internal resistance. It was also confirmed that the range of fluorochemicals was formed on the electrode surface for approximately 10 nm in depth using electron spectroscopy for chemical analysis (ESCA). From the chemical analysis of the electrolyte using an inductively coupling plasma emission analyzer (ICP-OES), it was confirmed that the electrolyte included silicon which is one of the ingredient elements of an electrode and that the increase in holding voltage in the stress test decreased the silicon density in the electrolyte.

DOI： 10.1002/ecj.11911

Plasma Sterilization of Anthrax Pathogen in Water Mist

Chemical Analysis of Casual Elements for Deterioration of Cylindrical EDLC 査読あり

Hiroumu Yoshitama, Daisuke Tashima, Tatsuya Sakoda, Noriyuki Hayashi, Masamitsu Yuhara, Takashi Utsunomiya

Electronics and Communications in Japan 135 ( 12 ) 792 - 798 2016年12月

記述言語：英語掲載種別：研究論文（学術雑誌）

マンゴー炭疽病菌の分生胞子の殺菌に必要なオゾン濃度および処理時間に関する研究査読あり

富永大, 田中聡之, 迫田達也, 溝口則和, 櫛間義幸

電気学会論文誌 A 136 ( 11 ) 726 - 727 2016年11月

記述言語：日本語掲載種別：研究論文（学術雑誌）

Detection of Partial Discharges in Electric Power Equipment using an Electromagnetic Wave Sensor 査読あり

Yugo Shirahama, Toshiki Hirashima, Mitsuki Kawakone, Takuma Miyake, Tatsuya Sakoda

Joint Conference of IWHV2016 & JK2016 on ED&HVE 51 - 54 2016年11月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Study on improvement of discharge characteristics of a surge arrester with a spark gap 査読あり

Hibiki Horie, Takuma Miyake, Tatsuya Sakoda, Tatsuya Tokunaga, Katsutaka Kubo, Manabu Mizutani, Takato Fukano

Joint Conference of IWHV2016 & JK2016 on ED&HVE 81 - 85 2016年11月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Numerical Analysis of I-V Characteristics and Siode Currents of a PV Module Reflected by Partial Shadow 査読あり

C. I. Wade, R. Torihara, Y. Fukamachi, T. Sakoda, N. Hayashi

2016 IEEE Region 10 Conference (TENCON) 2644 - 2647 2016年11月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

STERILIZATION OF COLLETOTRICHUM SP. USING A DISCHARGE SOURCE 査読あり

Takeshi Nishimura, Masaru Tominaga, Junichiro Tsuchida, Tatsuya Sakoda, Norikazu Mizoguchi, Yoshiyuki Kushima

The First International Conference on Hybridized Agriculture 40 - 46 2016年10月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

AE及び電磁波センサを用いた部分放電検出”,宮崎大学工学部紀要

朝倉匡俊, 井平学, 三宅琢磨, 迫田達也, 壱岐祐典, 前田健作

宮崎大学工学部紀要 45 181 - 185 2016年7月

記述言語：日本語掲載種別：研究論文（大学，研究機関等紀要）

絶縁ゴムのトラッキング劣化過程におけるAE信号特性

平島俊紀，白浜優吾，中村友哉，三宅琢磨，迫田達也，緒方貴仁，鎌田文麿，副島通邦

宮崎大学工学部紀要 45 ( 199 ) 204 2016年7月

記述言語：日本語掲載種別：研究論文（大学，研究機関等紀要）

マンゴーに発生する病害にプラズマ処理が与える影響

堂園大雅, 富永大, 迫田達也, 溝口則和, 櫛間義幸

宮崎大学工学部紀要 45 193 - 198 2016年7月

記述言語：日本語掲載種別：研究論文（大学，研究機関等紀要）

ポリマー材料の傾斜角度がポリマー表面の放電特性に与える影響

出口竜也, 枦健一, 三宅琢磨, 迫田達也, 阿嘉良昌, 安食富和, 深野孝人

出宮崎大学工学部紀要 45 187 - 192 2016年7月

記述言語：日本語掲載種別：研究論文（大学，研究機関等紀要）

熱電発電システムにおける開放電圧を用いた最大出力点の探索法査読あり

奥将俊，石津智子，田島大輔，迫田達也，林則行，穂高一条

太陽エネルギー 42 ( 4 ) 49 - 55 2016年4月

記述言語：日本語掲載種別：研究論文（学術雑誌）

電力ケーブル接続部に有効な周波数加速劣化試験の基礎的検討査読あり

井平学, 平島俊紀, 三宅琢磨, 迫田達也, 中野亮介, 鎌田文麿, 西昌美

電気学会論文誌A 136 ( 3 ) 241 - 242 2016年3月

記述言語：日本語掲載種別：研究論文（学術雑誌）

Tominaga M., Tanaka T., Sakoda T., Mizoguchi N., Kushima Y.

Proceedings - 2015 IIAI 4th International Congress on Advanced Applied Informatics, IIAI-AAI 2015 690 - 694 2016年1月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Proceedings - 2015 IIAI 4th International Congress on Advanced Applied Informatics, IIAI-AAI 2015

© 2015 IEEE. Miyazaki prefecture in Japan promotes agricultural food industry in recent year. One of the activities is promotion of agricultural and livestock products. However, Miyazaki prefecture is very far from large-scale consumption areas such as Tokyo and Osaka. To keep freshness of agricultural and livestock products during their transport is a serious problem from a viewing of putrefaction due to blight outbreak. Apple Mango has been a very famous and representative product in Miyazaki prefecture and it has successfully continued to make a good profit. However, fruit rot disease such as Anthrax Pathogen after harvest is serious [1] [2] [3]. Therefore, a sterilization technique is strongly required. We here generated the dielectric barrier discharge plasma in water mist, which may possible to sterilize the whole of greengrocery because of its high diffusibility. We examined fungicidal activity against Colletotrichum sp.

DOI： 10.1109/IIAI-AAI.2015.244

Examination of B. Subtilis spore sterilization by an underwater-Ar-plasma

Hamada T., Mine T., Sakoda T.

IEEJ Transactions on Fundamentals and Materials 136 ( 1 ) 64 - 65 2016年1月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEJ Transactions on Fundamentals and Materials

Advanced oxidation process (AOP) with hydroxyl radicals (OH) is considered to be useful for sterilization; therefore, we have proposed an underwater plasma source with a porous glass membrane which functioned in bubble supply and the formation of micro-discharges. In this study, we first examined whether B. subtilis spores could be sterilized by the underwater plasma of which operating gas was argon. Next, similar experiment was conducted by using mannitol, and the numbers of colonies were compared. The obtained results showed that OH radicals generated at gas-liquid interface were responsible for the sterilization.

DOI： 10.1541/ieejfms.136.64

Basic study on frequency accelerated aging test for joint section of XLPE cable

多孔質膜利用の水中アルゴンプラズマによる芽胞菌殺菌機構の考察査読あり

濱田俊之, 峰大樹, 迫田　達也

電気学会論文誌A 136 ( 1 ) 64 - 65 2016年1月

記述言語：日本語掲載種別：研究論文（学術雑誌）

Ihira M., Hirashima T., Miyake T., Sakoda T., Nakano R., Kamata F., Nishi M.

IEEJ Transactions on Fundamentals and Materials 136 ( 3 ) 155 - 156 2016年

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEJ Transactions on Fundamentals and Materials

© 2016 The Institute of Electrical Engineers of Japan. We studied usefulness of a frequency accelerated aging test by paying attention to the number of partial discharge (PD) pulses and the accumulated PD charges per a cycle of frequency of applied voltage. The results shows that a frequency accelerated aging test is useful when the accumulated PD charges per a cycle of frequency of applied voltage with higher than PD inception voltage are the almost same as that at a commercial frequency of 60 Hz. If applied frequency is 1 kHz, an accelerated aging test with 16.6 times faster than that for 60 Hz can be achieved.

DOI： 10.1541/ieejfms.136.155

Study on ozone concentration and process time required for sterilization of conidiospore of colletotrichwn sp.

Tominaga M., Tanaka T., Sakoda T., Mizoguchi N., Kushima Y.

IEEJ Transactions on Fundamentals and Materials 136 ( 11 ) 726 - 727 2016年

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEJ Transactions on Fundamentals and Materials

© 2016 The Institute of Electrical Engineers of Japan. To investigate optimal concentration of O3 and process time for sterilization of conidiospore of Colletotrichum sp.. we examined sterilization by using CT (product of concentration and process time) as a sterilization index. The results showed that the usual CT was not be useful for interpreting sterilization.

DOI： 10.1541/ieejfms.136.726

Characteristics of an underwater plasma source with a porous glass membrane

Shiomitsu E., Sakoda T.

Electronics and Communications in Japan 98 ( 12 ) 72 - 79 2015年12月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Electronics and Communications in Japan

© 2015 Wiley Periodicals, Inc. The advanced oxidation process (AOP) with hydroxyl radicals (OH) is considered to be useful for water purification through oxidation; therefore, we proposed an underwater plasma source with a porous glass membrane which performed the functions of bubble supply and the formation of microdischarges. We observed bubble formation and light emission from discharges on the surface of the membrane using a high-speed camera and a spectroscope, respectively. In addition, the dependence of gas pressure on the generation of OH radical and the decomposition of recalcitrant organic matter were examined. The obtained results showed that AOP may be more effective when the operating gas pressure is set higher than a pressure which could form bubbles.

DOI： 10.1002/ecj.11772

Chemical analysis of causal elements for deterioration of cylindrical EDLC

Yoshitama H., Tashima D., Sakoda T., Hayashi N., Yuhara M., Utsunomiya T.

IEEJ Transactions on Fundamentals and Materials 135 ( 12 ) 792 - 798 2015年12月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEJ Transactions on Fundamentals and Materials

© 2015 The Institute of Electrical Engineers of Japan. Chemical analysis was carried out before and after the constant voltage hold test that was an acceleration deterioration examination to clarify deterioration factors of electric double-layer capacitor (EDLC). The results showed that the stress testslightly caused the increase of internal resistance. It was also confirmed that the range of fluorochemicals was formed on the electrode surface for approximately 10 nm in depth using electron spectroscopy for chemical analysis (ESCA). From the chemicalanalysis of the electrolyte using an inductively coupling plasma emission analyzer (ICP-OES), it was confirmed that the electrolyte included silicone which is one of the ingredient elements of an electrode and that the increase in holding voltage in the stress testdecreased the silicone density in the electrolyte.

DOI： 10.1541/ieejfms.135.792

Basic characteristics of a heat and electricity combined generation system using biomass fuel

化学分析による電気二重層キャパシタの劣化要因の考察査読あり

吉玉拓, 田島大輔, 迫田達也, 林則行, 湯原将光, 宇都宮隆

電気学会論文誌A 135 ( 12 ) 792 - 798 2015年12月

記述言語：日本語掲載種別：研究論文（学術雑誌）

Study on Plasma Sterilization of Plant Anthracnose Pathogen in Water Mist 査読あり

Masaru Tominaga, Toshiyuki Tanaka, Tatsuya Sakoda, Norikazu Mizoguchi, Yoshiyuki Kushima

Information Engineering Express, International Institute of Applied Informatics 1 ( 4 ) 11 - 20 2015年12月

記述言語：英語掲載種別：研究論文（学術雑誌）

Detection and Development of Partial Discharges for Vacuum Circuit Breaker using Electromagnetic Wave Sensors 査読あり

Masatoshi Asakura, Manabu Ihira, Takuma Miyake, Tatsuya Sakoda, Kensaku Maeda, Yusuke Iki

2015 Korea-Japan Joint Symposium on Electrical Discharge and HV Engineering 31 - 34 2015年11月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Characteristics of flashover on polluted polymer surface 査読あり

Tatsuya Sakoda, Daichi Yamashita, Tatsuya Deguchi, Takuma Miyake, Noriyuki Hayashi, Kenich Haji, Yoshimasa Aka, Tomikazu Anjiki, and Takato Fukano

2015 Korea-Japan Joint Symposium on Electrical Discharge and HV Engineering 81 - 84 2015年11月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

触媒層の違いによる固体高分子形燃料電池用MEA の劣化特性

古澤伸仁, 田島大輔, 迫田達也, 林則行

宮崎大学工学部紀要 41 - 47 2015年7月

記述言語：日本語掲載種別：研究論文（大学，研究機関等紀要）

シリコーン材料の劣化特性の評価

陣内雅人, 山下大地, 岩本丈, 三宅琢磨, 迫田達也

宮崎大学工学部紀要 33 - 40 2015年7月

記述言語：日本語掲載種別：研究論文（大学，研究機関等紀要）

柚子を用いた電気二重層キャパシタ用炭素材料の開発

上栗伸仁, 田島大輔, 迫田達也, 林則行

宮崎大学工学部紀要 9 - 12 2015年7月

記述言語：日本語掲載種別：研究論文（大学，研究機関等紀要）

低周波から中間周波における人体内部インピーダンス測定装置の開発

堀晃太郎, 麦谷翔平, 迫田達也, 林則行, 太良尾浩生

宮崎大学工学部紀要 27 - 31 2015年7月

記述言語：日本語掲載種別：研究論文（大学，研究機関等紀要）

Plasma Sterilization of Anthrax Pathogen in Water Mist 査読あり

Masaru Tominaga , Toshiyuki Tanaka , Tatsuya Sakoda , Norikazu Mizoguchi , Yoshiyuki Kushima

2015 IIAI 4th International Congress on Advanced Applied Informatics 690 - 694 2015年7月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Influence of Operation Modes of a Cooling Pump on Thermal and Electrical Properties of Thermoelectric Generator System 査読あり

Toshitsugu Ishikawa, Masatoshi Oku, Daisuke Tashima, Tatsuya Sakoda, Noriyuki Hayashi

The International Conference on Electrical Engineering ( 15A-192-FP ) 1 - 4 2015年7月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Evaluation of Tracking Deterioration for a Plug in Elbow by an Acoustic Emission Technique 査読あり

Toshiki, Hirashima, Kenta, Miyabe, Tatsuya, Sakoda, Ryosuke, Nakano, Fumimaro, Kamada Masami, Nishi

The International Conference on Electrical Engineering ( 15A-206-FP ) 1 - 4 2015年7月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Detection of Partial Discharges for Vacuum Circuit Breaker in Cubicle using Acoustic Emission and Electromagnetic Wave sensors 査読あり

Masatoshi Asakura, Manabu Ihira, Takuma Miyake, Tatsuya Sakoda, Yusuke Iki, Ryuya Kida

The International Conference on Electrical Engineering ( 15A-122-FP ) 1 - 4 2015年7月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Influence of Shed Inclination on Discharge Ignition under DC Voltage Application 査読あり

D. Yamashita, T. Miyake, T. Sakoda, Y. Aka, T. Anjiki, and T. Fukano

2015 Asia-Pacific International Conference on Lightning (APL) 569 - 572 2015年6月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Observation of Creeping Flashover on ZnO element 査読あり

T. Sakoda and D. Tashima

2015 Asia-Pacific International Conference on Lightning (APL) 693 - 696 2015年6月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Development of polymer housed surge arrester applied to D.C. railway systems 査読あり

Y. Aka, T. Fukano, Y. Kasuga, T. Anjiki and T. Sakoda

2015 Asia-Pacific International Conference on Lightning (APL) 137 - 140 2015年6月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Detection of Partial Discharge in Cubicle 査読あり

Manabu Ihira, Masatoshi Asakura, Takuma Miyake, Tatsuya Sakoda, Yusuke Iki, Ryuya Kida

The 17th Asian Conference on Electrical Discharge 31-1 - 31-4 2014年12月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Sterilization Characteristics of Underwater Plasma 査読あり

Taiki Mine,Taiga Douzono, Tatuya Sakoda, Norikazu Mizoguchi

The 17th Asian Conference on Electrical Discharge 1-1 - 1-4 2014年12月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Basic Characteristics of a Heat and Electricity Combined Generation System Using Biomass Fuel 査読あり

Masatoshi Oku, Noriyuki Hayashi, Tatsuya Sakoda, Daisuke Tashima

3rd The International Conference on Renewable Energy Research and Applications 222 - 227 2014年10月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Basic Characteristics of a Heat and Electricity Combined Generation System Using Biomass Fuel 査読あり

Masatoshi Oku, Noriyuki Hayashi, Tatsuya Sakoda, Daisuke Tashima

Proceedings of the 3rd International Conference on Renewable Energy Research and Applications 222 - 228 2014年10月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

電気二重層キャパシタの劣化要因に関する考察査読あり

吉玉拓, 春田篤二, 田島大輔, 迫田達也

電気学会論文誌A 134 ( 10 ) 525 - 531 2014年10月

記述言語：日本語掲載種別：研究論文（学術雑誌）

GAS-LIQUID INTERFACIAL DISCHARGE WITH A POROUS GLASS MEMBRANE 査読あり

T. SAKODA and T. MINE

Proceedings of the XXth International Conference on Gas Discharges and their Applications 562 - 565 2014年7月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Compensation of output power characteristics of a partly-malfunctioned thermoelectric generator system by using a diode bypass circuit 査読あり

Masatoshi Oku, Daisuke Tashima, Tatsuya Sakoda, Noriyuki Hayashi

Proceedings of International Conference on Electrical Engineering 2014 384 - 389 2014年6月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

クロスボンド接続を有するケーブルにおける部分放電位置標定法に関する基礎的検討査読あり

北島純一, 迫田達也, 渡部清範

電気学会論文誌A 134 ( 6 ) 428 - 429 2014年6月

記述言語：日本語掲載種別：研究論文（学術雑誌）

多孔質ガラス膜を用いた水中放電プラズマ発生装置の特性査読あり

塩満栄一, 迫田達也

電気学会論文誌A 134 ( 5 ) 321 - 326 2014年5月

記述言語：日本語掲載種別：研究論文（学術雑誌）

Oku M., Sakoda T., Hayashi N., Tashima D.

3rd International Conference on Renewable Energy Research and Applications, ICRERA 2014 222 - 228 2014年1月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：3rd International Conference on Renewable Energy Research and Applications, ICRERA 2014

© 2014 IEEE. In this paper, we propose a unique co-generation system including a biomass boiler-using a thermoelectric generator (TEG). The boiler burned biomass fuel derived from a cow dung. In this system, warm water is generated through heat exchange in the boiler, and electricity is generated through the TEG that uses the high temperature of an exhaust gas from the boiler. In this study, the co-generation system was not well optimized, with the result that both the heat exchange efficiency of the biomass boiler and hence, - the amount of electric power generated were very low. However, the study demonstrated that the co-generation system that using the biomass as a heat source, and a TEG as an electric power generator can provide an effective energy source.

DOI： 10.1109/ICRERA.2014.7016560

Basic study on partial discharge location for cross-bonding cables

Kitajima J., Sakoda T., Watanabe K.

IEEJ Transactions on Fundamentals and Materials 134 ( 6 ) 428 - 429 2014年

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEJ Transactions on Fundamentals and Materials

To locate partial discharges (PDs) in cross-bonding cables where current pulses due to PDs might be divided, we paid attention to phases of current pulses obtained by six CT sensors arranged at both sides of 3-phase of the cables. The accuracy of PD location, obtained by using time difference between arrival times of current pulses from specified phase, was relatively high even for cross-bonding cables. © 2014 The Institute of Electrical Engineers of Japan.

DOI： 10.1541/ieejfms.134.428

Characteristics of an underwater plasma source with a porous glass membrane

Shiomitsu E., Sakoda T.

IEEJ Transactions on Fundamentals and Materials 134 ( 5 ) 321 - 326 2014年

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEJ Transactions on Fundamentals and Materials

Advanced oxidation process (AOP) with hydroxyl radicals (OH) is considered to be useful for water purification through oxidation; therefore, we proposed an underwater plasma source with a porous glass membrane which functioned in bubble supply and the formation of micro-discharges. We observed bubble formation and light emission from discharge on the surface of the membrane using a high-speed camera and a spectroscope, respectively. Additionally, dependence of gas pressure on generation of OH radical and decomposition of recalcitrant organic matter were examined. The obtained results showed that AOP might be more effective when the operating gas pressure was set higher than a pressure which could form bubbles. © 2014 The Institute of Electrical Engineers of Japan.

DOI： 10.1541/ieejfms.134.321

Study on deterioration factors of an electric double-layer capacitor

Yoshitama H., Haruta A., Tashima D., Sakoda T., Hayashi N.

IEEJ Transactions on Fundamentals and Materials 134 ( 10 ) 525 - 531 2014年

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEJ Transactions on Fundamentals and Materials

© 2014 The Institute of Electrical Engineers of Japan. Electric double-layer capacitors (EDLCs) have the advantages of much longer life and unnecessary maintenance. However, for EDLCs used for a long period, a decrease of electrostatic capacity and an increase in internal resistance are recognized. In this study, in order to clarify the factors responsible for the deterioration of EDLCs used for a long period, chemical analysis was conducted on each component such as an activated carbon electrode and an electrolytes solution. The obtained data were compared with those from a new EDLC. The results showed that long-term use reduced electrostatic capacity about 5% and made internal resistance increase by about 1.7 times. The quantity of oxygen due to surface functional groups of the activated carbon electrode was confirmed using electron spectroscopy for chemical analysis (ESCA). As compared with results obtained from a new EDLC, long-term use made the ratio of O-C=O deriving from carboxyl group (-COOH) to C-C increase 1.2 times. The ratio of C-O deriving from hydroxyl group (-OH) to C-C also increased 1.4 times. In addition, it was found that BET surface area decreased about 40% and that pores whose diameter was in the range between 0.8 to 20 nm disappeared.

DOI： 10.1541/ieejfms.134.525

Influence on bleaching characteristics by different discharge form for a passing water-type ozonizer

Shiomitsu E., Ariyoshi J., Fuji S., Sakoda T., Kijima J., Nakashima H.

IEEJ Transactions on Fundamentals and Materials 133 ( 11 ) 606 - 607 2013年11月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEJ Transactions on Fundamentals and Materials

Advanced oxidation process (AOP) with hydroxyl radicals (OH) is considered to be useful for water purification through oxidation; therefore, we proposed a useful passing water-type ozonizer, which could generate discharges even on the liquid surface. We first observed optical emissions due to the discharges and then confirmed the existence of O and OH radicals. Next, decomposition of Methylene Blue was examined. When the discharge was generated between a glass electrode and liquid, the AOP was achieved. The obtained results also indicated that various decomposition and treatment would be possible by selecting discharge form for our passing water-type ozonizer.

DOI： 10.1541/ieejfms.133.606

Influence of triple-junction on sparkover voltage for a series gap of arrester

通水型オゾナイザの放電形態が脱色特性に与える影響査読あり

塩満栄一, 有吉純也, 藤真介, 迫田達也, 貴島純次, 中島秀之

電気学会論文誌A 133 ( 11 ) 606 - 607 2013年11月

記述言語：日本語掲載種別：研究論文（学術雑誌）

Tokunaga T., Nishikawa S., Sakoda T., Fukano T.

2013 IEEE Electrical Insulation Conference, EIC 2013 110 - 113 2013年9月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：2013 IEEE Electrical Insulation Conference, EIC 2013

Considering the latest development of advanced information society, a stable supply of electric power should be maintained. Lightning surge arrester can contribute to reduce electric failures due to overvoltage from lightning. Since 1970's, zinc oxide (ZnO) element with superior non-linear voltage (V) - current (I) characteristics has been widely installed. Even in Japan, the surge arrester with a series gap has been installed to distribution systems for reducing the electrical failures. As mentioned above, the ZnO element has a superior nonlinearity of V-I characteristic, which can achieve suppress of overvoltage energy. Furthermore, the ZnO surge arrester with a series gap can interrupt the following current, immediately. The surge arrester with a series gap is composed of a simple gap electrode, a ceramic spacer for fixing the gap of the electrodes, and ZnO elements. The upper and the bottom of the ceramic spacer face metallic electrodes; therefore there are triple-junction points between the ceramic spacer, the metallic electrode, and gas. It is well known that electric field strength near the triple-junction point becomes high because of a triple-junction effect. It is also considered that the triple-junction point becomes a source of primary electrons by field emission due to the high electric field. Therefore, the triple-junction effect may influence the discharge characteristics so that the investigation will contribute to the further stable operation of a surge arrester with a series gap. In this study, we carried out experiments concerning how the triple-junction effect influences discharge characteristics such as breakdown voltage and discharge ignition. We first varied the distance between the discharge axis and the triple-junction point and then evaluated the discharge ignition time. Additionally, several ceramic materials with various relative permittivity were used. Based on the results, we evaluated the optimum distance between the discharge axis and the triple-junction point, which would be useful for design of a surge arrester with a series gap. © 2013 IEEE.

DOI： 10.1109/EIC.2013.6554214

Evaluation of discharge ignition by composite pollution test with silicone rubber

Oshikawa N., Tokunaga T., Honda K., Miyake T., Sakoda T., Anjiki T.

IEEJ Transactions on Fundamentals and Materials 133 ( 4 ) 205 - 210 2013年5月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEJ Transactions on Fundamentals and Materials

Application of polymeric materials for electric power apparatus is spreading worldwide. However, the aged deterioration is anxious because of dry band arc discharges generated on the surface of the polymer materials. In this paper, we carried out composite pollution tests and measured the discharge ignition time of silicone rubber. The results showed that there was no large difference in the discharge ignition times obtained between ac and dc voltage applications. Additionally, it was shown that the difference of the discharge ignition was influenced by hygroscopic property of the pollution material. © 2013 The Institute of Electrical Engineers of Japan.

DOI： 10.1541/ieejfms.133.205

多孔質誘電体を用いた水中プラズマ発生装置の特性評価

複合汚損試験によるシリコーンゴム表面上の放電開始時間の評価査読あり

押川典仁, 徳永達也, 本田一史, 三宅琢磨,　迫田達也, 安食富和

電気学会論文誌A 133 ( 4 ) 205 - 210 2013年4月

記述言語：日本語掲載種別：研究論文（学術雑誌）

塩満栄一, 木野裕晶, 湯地翔平, 迫田達也, 貴島純次, 中島秀之

電気学会研究会資料. DEI, 誘電・絶縁材料研究会 2013 ( 10 ) 25 - 29 2013年1月

記述言語：日本語掲載種別：研究論文（学術雑誌）

放電ギャップ近傍の高電界部がインパルス放電特性に与える影響の評価

徳永達也, 西川慎之介, 迫田達也, 深野孝人, 千葉智基

電気学会研究会資料. ED, 放電研究会 2013 ( 1 ) 39 - 42 2013年1月

記述言語：日本語掲載種別：研究論文（学術雑誌）

放電ギャップ近傍の高電界部がインパルス放電特性に与える影響の評価

徳永達也, 西川慎之介, 迫田達也, 深野孝人, 千葉智基

電気学会研究会資料. DEI, 誘電・絶縁材料研究会 2013 ( 10 ) 39 - 42 2013年1月

記述言語：日本語掲載種別：研究論文（学術雑誌）

放電ギャップ近傍の高電界部がインパルス放電特性に与える影響の評価

徳永達也, 西川慎之介, 迫田達也, 深野孝人, 千葉智基

電気学会研究会資料. HV, 高電圧研究会 2013 ( 42 ) 39 - 42 2013年1月

記述言語：日本語掲載種別：研究論文（学術雑誌）

多孔質誘電体を用いた水中プラズマ発生装置の特性評価

塩満栄一, 木野裕晶, 湯地翔平, 迫田達也, 貴島純次, 中島秀之

電気学会研究会資料. ED, 放電研究会 2013 ( 1 ) 25 - 29 2013年1月

記述言語：日本語掲載種別：研究論文（学術雑誌）

多孔質誘電体を用いた水中プラズマ発生装置の特性評価

塩満栄一, 木野裕晶, 湯地翔平, 迫田達也, 貴島純次, 中島秀之

電気学会研究会資料. HV, 高電圧研究会 2013 ( 42 ) 25 - 29 2013年1月

記述言語：日本語掲載種別：研究論文（学術雑誌）

電気絶縁機器用ポリマー外被材の直流・交流時の電気的特性の評価査読あり

三宅琢磨, 瀬尾裕也, 押川典仁, 迫田達也, 大坪昌久, 安食富和

電気設備学会誌 32 ( 8 ) 594 - 599 2012年12月

記述言語：日本語掲載種別：研究論文（学術雑誌）

微細藻類がポリマーがいし外被材の絶縁特性に与える影響の評価査読あり

本田一史, 押川典仁, 三宅琢磨, 迫田達也, 吉田ナオト, 古河征二

電気学会論文誌A 132 ( 11 ) 944 - 950 2012年12月

記述言語：日本語掲載種別：研究論文（学術雑誌）

Insulation characteristics of polymer insulator materials with algaes

Honda K., Oshikawa N., Miyake T., Sakoda T., Yoshida N., Furukawa S.

IEEJ Transactions on Fundamentals and Materials 132 ( 11 ) 944 - 950 2012年11月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEJ Transactions on Fundamentals and Materials

Polymer insulator has some excellent properties such as being lightweight, hydrophobicity, and antiweatherability. However, the polymer material is made from organic matters whereby the aged deterioration due to electric discharges, polluted deposited, and microbes is worrying. In this study, we first investigated existence and kind of microbes on the surface of silicone rubber (SiR) insulators arranged outdoor for 11 years. Next, to investigate how the microbes influence insulation performance of polymeric materials, the salt fog tests were performed on SiR samples with the artificial cultured microbes. The microbes temporally increased the leakage current due to discharges; however, the degradation didn't continue because the discharges rejected the microbes. © 2012 The Institute of Electrical Engineers of Japan.

DOI： 10.1541/ieejfms.132.944

Frequency dependence on etching characteristics of silicon using surface discharge plasma

Arimura T., Hirano K., Hamada T., Sakoda T.

IEEJ Transactions on Fundamentals and Materials 132 ( 4 ) 333 - 334 2012年10月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEJ Transactions on Fundamentals and Materials

We proposed a maskless plasma etching technique for fabrication of front contact grooves on a single crystalline silicon solar cell. In this paper, we evaluated characteristics of silicon etching with various output frequency of ac power source. The etching rate in the direction of the groove width was suppressed while that in the direction of the groove depth increased with increasing output frequency of the power source. Thus, it was found that the increase of output frequency of a power source was effective in the case where the surface discharge plasma was applied to patterning. © 2012 The Institute of Electrical Engineers of Japan.

DOI： 10.1541/ieejfms.132.333

Maximum output power control using short-circuit current and open-circuit voltage of a solar panel

Maximum Output Power Control using Short-Circuit Current and Open-Circuit Voltage of a Solar Panel 査読あり

Takahiro Kato, Takuma Miyake, Daisuke Tashima, Tatsuya Sakoda, Masahisa Otsubo, Mitsuyuki Hombu

Japanese Journal of Applied Physics 10 ( 51 ) 10NF08-1 - 10NF08-4 2012年10月

記述言語：英語掲載種別：研究論文（学術雑誌）

Kato T., Miyake T., Tashima D., Sakoda T., Otsubo M., Hombu M.

Japanese Journal of Applied Physics 51 ( 10 PART 2 ) 1 - 10 2012年10月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Japanese Journal of Applied Physics

A control method to optimize the output power of a solar cell is necessary because the output of a solar cell strongly depends on solar radiation. We here proposed two output power control methods using the short-circuit current and open-circuit voltage of a solar panel. One of them used a current ratio and a voltage ratio (αβ control), and the other used a current ratio and a short-circuit current-electric power characteristic coefficient (αγ control). The usefulness of the αβ and the αγ control methods was evaluated. The results showed that the output power controlled by our proposed methods was close to the maximum output power of a solar panel. © 2012 The Japan Society of Applied Physics.

DOI： 10.1143/JJAP.51.10NF08

Characteristics of powdered activated carbon treated with dielectric barrier discharge for electric double-layer capacitors

Tashima D., Yoshitama H., Sakoda T., Okazaki A., Kawaji T.

Electrochimica Acta 77 198 - 203 2012年8月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Electrochimica Acta

The electrochemical properties of electric double-layer capacitors (EDLCs) made with plasma-treated powdered activated carbon (treated using a dielectric barrier discharge) were examined using cyclic voltammetry (CV), Cole-Cole plots, and X-ray photoelectron spectroscopy (XPS). The dielectric barrier discharge method, which operates at atmospheric pressure, dramatically reduces the processing time and does not require vacuum equipment, making it a more practical alternative than low-pressure plasma treatment. The experimental data indicate that the specific capacitance of the EDLCs could be improved by oxygen plasma treatment. Capacitance of EDLCs made with activated carbon treated for 15 s showed 193.5 F/g that 20% increase in the specific capacitance relative to untreated EDLCs. This result indicates that the plasma treatment yields EDLCs that are suitable for high-energy applications. The enhancement of capacitance was mainly attributed to an increase in the BET surface area of the activated carbon and the creation of carboxyl groups on the surface of t he carbon. The carboxyl groups induced oxidation-reduction reactions in the presence of O 2 which was included in the operation gas. In addition, the carboxyl groups improved the penetration of the electrolyte solution into the carbon electrodes. © 2012 Elsevier Ltd All rights reserved.

DOI： 10.1016/j.electacta.2012.05.105

電力設備用ポリマー外被材の直流・交流課電時の電気的特性

三宅琢磨, 瀬尾裕也, 押川典仁, 迫田達也, 大坪昌久, 安食富和

電気設備学会誌 32 ( 8 ) 594 - 599 2012年8月

記述言語：日本語掲載種別：研究論文（学術雑誌）

Characteristics of powdered activated carbon treated with dielectric barrier discharge for electric double-layer capacitors 査読あり

Daisuke Tashima, Hiromu Yoshitama, Tatsuya Sakoda, Akihito Okazaki, Takayuki Kawaji

Electrochimica Acta 77 198 - 203 2012年5月

記述言語：英語掲載種別：研究論文（学術雑誌）

沿面放電プラズマを用いたSiエッチングの電源周波数依存性査読あり

有村拓也, 平野啓太, 濱田俊之, 迫田達也

電気学会論文誌A 132 ( 4 ) 333 - 334 2012年4月

記述言語：日本語掲載種別：研究論文（学術雑誌）

Studies on optimal gas supply for a maskless etching system with micro-discharge plasma operated at atmospheric pressure

Hamada T., Arimura T., Sakoda T.

Plasma Chemistry and Plasma Processing 32 ( 2 ) 325 - 332 2012年4月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Plasma Chemistry and Plasma Processing

An optimal gas supply method for the micro discharge plasma generated along a quartz glass electrode, which was useful for the maskless fabrication of electrode grooves for surface electrodes on solar cells, was examined. We here constructed an electrode system with gas inlet and outlet holes. The gas supply directly to the plasma region contributed to reduce byproducts on the surface being etched, and then it was confirmed that the uniform etching was achieved in the case where the micro-discharge plasma locally produced at the etching area. © Springer Science+Business Media, LLC 2011.

DOI： 10.1007/s11090-011-9343-y

ポリマー碍子外被材料に植生する藻類が絶縁特性に与える影響

Studies on optimal gas supply for a maskless etching system with micro- discharge plasma operated at atmospheric pressure 査読あり

Toshiyuki Hamada, Takuya Arimura, Tatsuya Sakoda

Plasma Chemistry and Plasma Processing 32 ( 2 ) 325 - 332 2012年3月

記述言語：英語掲載種別：研究論文（学術雑誌）

本田一史, 押川典仁, 三宅琢磨, 迫田達也, 大坪昌久, 古河征二, 田中賢示

電気学会研究会資料. DEI, 誘電・絶縁材料研究会 2012 ( 13 ) 37 - 42 2012年1月

記述言語：日本語掲載種別：研究論文（学術雑誌）

ポリマー碍子外被材料に植生する藻類が絶縁特性に与える影響

本田一史, 押川典仁, 三宅琢磨, 迫田達也, 大坪昌久, 古河征二, 田中賢示

電気学会研究会資料. ED, 放電研究会 2012 ( 1 ) 37 - 42 2012年1月

記述言語：日本語掲載種別：研究論文（学術雑誌）

Characteristics of hydrophobicity loss on silicone rubber surface during a dynamic drop test with direct current voltage application 査読あり

Yuya Seo, Norihito Oshikawa, Takuma Miyake, Tatsuya Sakoda, and Tomikazu Anjiki

Nanoscale Research Letters 7 ( 4 ) 1 - 4 2012年1月

記述言語：英語掲載種別：研究論文（学術雑誌）

電力設備用ポリマー外被材の直流・交流課電時の電気的特性

三宅琢磨, 瀬尾裕也, 押川典仁, 迫田達也, 大坪昌久, 安食富和

電気設備学会誌 32 ( 8 ) 593 - 599 2012年

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：The Institute of Electrical Installation Engineers of Japan

Recently，much attention has been paid to polymeric materials used for housing of electric power apparatus. However，because polymeric material is made by organic matters，the aged deterioration is anxious. The lifetime of polymeric material is influenced by environmental conditions such as ultraviolet，acid rain，and polluted deposits. The change of the surface condition of polymeric material causes dry band arc discharges. To understand the long-term reliability of the insulation performance of polymeric materials，a composite pollution test of a liquid silicone rubber (LSR) was performed with dc or ac voltage application. After the test，heavy erosion was confirmed around a cathode electrode when dc voltage was applied. In the case of ac voltage application，heavy erosion was confirmed around a grounding electrode. It was also found that the initiation time of leakage current and cumulative charge depended on the kind of polluted deposits and that the difference of cumulative charge among polluted deposits in the case of dc voltage application was larger than that in the case of ac voltage application.

DOI： 10.14936/ieiej.32.593

Electrochemical capacitances of carbon powder treated with dielectric barrier discharge

Tashima D., Hirakawa R., Sakoda T., Otsubo M.

Annual Report - Conference on Electrical Insulation and Dielectric Phenomena, CEIDP 2011 Vol.1 109 - 112 2011年12月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Annual Report - Conference on Electrical Insulation and Dielectric Phenomena, CEIDP

Powdery activated carbons were treated using dielectric barrier discharge. In comparison with low pressure plasma, dielectric barrier discharge operated at atmospheric pressure can dramatically reduce the processing time and does not need vacuum equipment. In this study, electrochemical properties of Electric Double Layer Capacitors (EDLCs) made of oxygen plasma-treated powdery activated carbons were examined through Cyclic Voltammetry (CV), cole-cole plots and X-ray Photoelectron Spectroscopy (XPS). It was found that the specific capacitance of EDLCs could be improved by using oxygen plasma-treated activated carbon powder. A comparison of EDLCs using carbon powder treated for 15 S versus untreated EDLCs shows a 20% increase in specific capacitance, which indicates that the plasma treatment for EDLC's carbon powder are suitable for high-energy applications. The enhancement of capacitance was mainly attributed to an increase in the BET surface area of the carbon powder and the creation of phenolic hydroxyl groups on the surface of the carbon. The phenolic hydroxyl groups caused oxidation-reduction reactions, because oxygen was included in the operation gas. In addition, the phenolic hydroxyl groups improved the penetration of the electrolyte solution. © 2011 IEEE.

DOI： 10.1109/CEIDP.2011.6232608

複合汚損試験によるシリコーンゴムの放電開始時間の検討

ケーブル接続部材中の複数放電によるAE信号の評価

中村祐太, 平野啓太, 北島純一, 迫田達也, 栗原聡史, 金子幸市朗, 鎗光隆義

電気学会研究会資料. HV, 高電圧研究会 2011 ( 67 ) 81 - 84 2011年11月

記述言語：日本語掲載種別：研究論文（学術雑誌）

押川典仁, 瀬尾裕也, 三宅琢磨, 迫田達也, 安食富和

電気学会研究会資料. HV, 高電圧研究会 2011 ( 67 ) 77 - 80 2011年11月

記述言語：日本語掲載種別：研究論文（学術雑誌）

Electrochemical Capacitances of Carbon Powder Treated with Dielectric Barrier Discharge 査読あり

D. Tashima, R. Hirakawa, T. Sakoda and M. Otsubo

IEEE Conference on Electrical Insulation And Dielectric Phenomena 2011年10月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Assessing long-term reliability of polymeric housing materials

Miyake T., Arata Y., Sakoda T., Otsubo M., Sonoda Y., Yamaguchi H.

IEEJ Transactions on Power and Energy 131 ( 6 ) 530 - 531 2011年9月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEJ Transactions on Power and Energy

Application of polymeric materials for housing of outdoor insulators is expected to rapidly increase in the near future. However, the lifetime and the aging deterioration, owing to environmental conditions, are concerned. To understand the long-term reliability of the insulation performance of polymeric materials, the salt fog tests were performed on the polymeric insulators made of ethylene vinyl acetate (EVA) and silicone rubber (SiR). The hydrophobicity was also evaluated. The samples which 11 years have passed since the installation were taken away from an actual distribution system in the region where pollution condition was comparatively severe. The results indicated that the polymeric insulators had enough insulation performance. © 2011 The Institute of Electrical Engineers of Japan.

DOI： 10.1541/ieejpes.131.530

Three-dimensional localization of partial discharge at joint section of XLPE cable using acoustic emission method combined with LabVIEW analysis

Nainggolan J., Sakoda T., Hayashi N., Kurihara S., Nagasato S., Kaneko K., Yarimitsu T.

European Journal of Scientific Research 59 ( 1 ) 134 - 142 2011年9月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：European Journal of Scientific Research

Acoustic emission (AE) sensor was used for detection of electric discharges and diagnosing a joint section of T-branch cross-linked polyethylene (XLPE) cable for 22 kV distribution system. From the head of cable joint, three AE sensors were arranged at the cable surface clockwise at 1200 to each other, and each sensor connected to an amplifier unit. Three AE sensors were used to generate three-dimensional calculation. A high voltage electrode was inserted into the joint section of cable, and then high voltage was applied to generate partial discharge (PD). PD current was detected by a Rogowski coil. The AE signal from the amplifier unit was sent to a digital oscilloscope and recorded in a personal computer for further analyses using LabVIEW. The correlation between AE signal and PD current was clarified. The increase of AE signal has the same linear tendency with increasing PD current. Thereafter, estimated three-dimensional PD locations were found around the head part of joint section of XLPE cable. © EuroJournals Publishing, Inc. 2011.

Fabrication of electrode groove on silicon solar cell by high-pressure surface discharge

Assessing Long-term Reliability of Polymeric Housing Materials 査読あり

Takuma Miyake, Yuya Seo, Tatsuya Sakoda, Masahisa Otsubo

Institute of Electrical Engineers of Japan Transactions on Power and Energy 131 ( 6 ) 530 - 531 2011年6月

記述言語：英語掲載種別：研究論文（学術雑誌）

Hamada T., Arakawa S., Otsubo M., Sakoda T.

Electronics and Communications in Japan 94 ( 4 ) 733 - 739 2011年4月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Electronics and Communications in Japan

We propose a low-cost plasma process technique to fabricate narrower front electrode grooves on a single crystalline silicon solar cell, in which a surface discharge operated at high pressure etches a silicon nitride film 150 nm thick on a silicon layer. Tests showed that the surface discharge could effectively etch the silicon nitride film in a short time; a high etching rate exceeding 3000 nm/min was obtained. Narrow and uniform grooves with a width of less than 70 μm were obtained when the pressure in the chamber, the back electrode length, and the etching time were 152 kPa, 2 mm, and 10 s, respectively. Narrower electrode grooves could be obtained when the back electrode length was short and the pressure was high. © 2011 Wiley Periodicals, Inc.

DOI： 10.1002/ecj.10305

運転中水車発電機固定子巻線部分放電特性に及ぼす温度の影響

日高徹, 金子正光, 三宅琢磨, 竹之内修, 林則行, 迫田達也, 大坪昌久

電気学会研究会資料. ED, 放電研究会 2011 ( 15 ) 25 - 28 2011年1月

記述言語：日本語掲載種別：研究論文（学術雑誌）

Comparison of degradation phenomena on silicone rubbers eroded by DC and AC discharges

Shiibara D., Arata Y., Sakoda T., Otsubo M., Anjiki T.

IEEJ Transactions on Fundamentals and Materials 130 ( 11 ) 1009 - 1012 2010年12月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEJ Transactions on Fundamentals and Materials

The salt fog tests for silicone rubbers (SiR) were performed under DC or AC voltage application. During a test, intensive discharges occurred around an earth electrode when positive DC voltage was applied. In the case of negative DC voltage application, intensive discharges occurred around an electrode which the voltage was applied. In other words, the intensive discharge concentrated around a cathode electrode, which caused heavy erosion around the electrode. In contrast, for the case of AC voltage application, the intensive discharge and heavy erosion did not occur. © 2010 The Institute of Electrical Engineers of Japan.

DOI： 10.1541/ieejfms.130.1009

Etching characteristics of fabricated grooves on silicon solar cell using surface discharge plasma

Hamada T., Sakoda T.

IEEJ Transactions on Fundamentals and Materials 130 ( 11 ) 999 - 1003 2010年12月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEJ Transactions on Fundamentals and Materials

A buried contact is one of effective techniques to improve the efficiency of solar cells. However, the etching of the patterned front contact on the surface of a solar cell is required. Therefore, we proposed a maskless etching technique using the surface discharge plasma operated at atmospheric pressure. The streamer-like discharge channels, which ignited near a triple junction point between the quartz glass layer, the solar cell, and the gas space, played an essential role in the etching. The etching rate of a silicon solar cell of which the surface had randomly distributed pyramid-like structures, was in the range of 3 - 5 μm/min when the applied voltage was 4.0 kV. © 2010 The Institute of Electrical Engineers of Japan.

DOI： 10.1541/ieejfms.130.999

Proposal of multi-pass laser spectroscopic technique for diagnosing atmospheric pressure discharge plasmas

Sakoda T., Bowden M.

IEEJ Transactions on Fundamentals and Materials 130 ( 11 ) 1026 - 1030 2010年12月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEJ Transactions on Fundamentals and Materials

We propose a multi-pass laser spectroscopic technique which is useful for diagnosing atmospheric pressure discharges. The key to the technique is to recycle a single laser pulse with low energy many times through the measurement area, avoiding the perturbation that a high energy pulse would induce while maintaining large signal levels. The pulse from a Q-switched laser is injected into an optical cavity, and a Pockels cell is used to rotate the polarization of the beam 90°, trapping it in the cavity. We set up this laser system and successfully obtained a semi-infinite series of pulses. © 2010 The Institute of Electrical Engineers of Japan.

DOI： 10.1541/ieejfms.130.1026

Studies on acoustic emission signals detected in an oil-immersed pole transformer

Yamamoto T., Nakashima T., Sakoda T., Otsubo M., Kurihara S., Nagasato S., Yarimitsu T.

IEEJ Transactions on Fundamentals and Materials 130 ( 11 ) 1031 - 1036 2010年12月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEJ Transactions on Fundamentals and Materials

Acoustic emission (AE) waves owing to partial discharges (PDs) in a 6 kV-oil-immersed pole transformer are influenced by windings, a magnetic core, and insulating paper because the AE waves proceed in all directions. To evaluate the amount of electrical charge due to a PD from AE signals detected by piezoelectric AE sensors, characteristics of AE signals obtained by arranging AE sensors at various positions were evaluated. We also investigated that the intensity ratio of frequency components of a detected AE signal was useful for estimating the rough location of a PD. © 2010 The Institute of Electrical Engineers of Japan.

DOI： 10.1541/ieejfms.130.1031

Relationship between leakage current and pollution deposits on the surface of polymeric insulator

Miyake T., Seo Y., Sakoda T., Otsubo M.

IEEJ Transactions on Fundamentals and Materials 130 ( 11 ) 1037 - 1041 2010年12月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEJ Transactions on Fundamentals and Materials

Application of polymeric materials used for housing insulators is considered. However, because polymeric insulator is organic matter, the aged deterioration is anxious. The lifetime of polymeric insulator is influenced by environmental conditions such as ultraviolet, acid rain, and polluted deposits. A change of the surface condition of polymeric material causes the dry band arc discharge and the discharge may lower the insulation strength. To investigate the relationship between insoluble pollution and occurrence of dry band arc discharge, we performed a salt-fog test with ethylene vinyl acetate (EVA) samples. The results showed that the heavy erosion caused by frequent dry band arc discharges occurred even in the case of a light polluted condition. Additionally, a very characteristic increase tendency in leakage current with a period of about 5 h was observed during the mist period. © 2010 The Institute of Electrical Engineers of Japan.

DOI： 10.1541/ieejfms.130.1037

Maskless etching using atmospheric pressure non-thermal surface discharge plasma

Hamada T., Mizumoto T., Arimura T., Sakoda T.

IEEJ Transactions on Fundamentals and Materials 130 ( 10 ) 907 - 912 2010年12月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEJ Transactions on Fundamentals and Materials

We proposed and examined a maskless plasma surface patterning technique to fabricate 3 mm pitches of front contact grooves on a single crystalline silicon solar cell, in which the surface discharge operated at atmospheric pressure etched the silicon nitride film of 150 nm thickness on a silicon layer. In addition, we investigated etching characteristics of flat surface silicon and the distribution of electric field in our proposed surface discharge etcher. The electrical field distribution of our proposed surface discharge etcher was concentrated at triple junction points, and its strength electrical field intensity was around 4.0 × 10 6 V/m. Finally, we showed that the surface discharge could effectively etch the silicon nitride film in a 3 mm pitch. © 2010 The Institute of Electrical Engineers of Japan.

Location of partial discharge at joint section of XLPE cable using acoustic emission technique

Nainggolan J., Nakashima T., Sakoda T., Otsubo M., Kurihara S., Nagasato S., Yarimitsu T.

Annual Report - Conference on Electrical Insulation and Dielectric Phenomena, CEIDP 2010 Vol.2 442 - 445 2010年12月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Annual Report - Conference on Electrical Insulation and Dielectric Phenomena, CEIDP

In this study, an acoustic emission (AE) technique was used for diagnosing a joint section of cross-linked polyethylene (XLPE) cable. The correlation between AE signal and partial discharge (PD) current was first investigated. The joint section of. XLPE cable was 22 kV T branch joint with a diameter of 91.6 mm. Three AE sensors were located at the cable surface, 140 mm and 130 mm from the head of cable joint. The sensors use magnet holders for detecting PDs. For each distance from the head of cable joint, the AE sensors were placed at cable surface with the angle deviations of 120 degrees. At the tip of the head of cable joint, an artificial void was made with a diameter of 1.5 mm. The AE signal detected by the AE sensors was amplified by a preamplifier and a main amplifier. A high voltage electrode was inserted into the joint section of XLPE cable, and then high voltage was applied to generate PDs. PD current was detected by a Rogowski coil. The AE signal from the main amplifier was sent to a digital oscilloscope and recorded in a personal computer for further analyses, such as the fast Fourier transform (FFT). The correlation between AE signal and PD current was clarified. The increase of AE signal has the same linear tendency with increasing PD current. Furthermore, estimated PD locations were found around the head part of joint section of XLPE cable. ©2010 IEEE.

DOI： 10.1109/CEIDP.2010.5723983

Study on change morphology of ZnO elements by a large impulse current

MIYAZAKI S., SAKODA T., OTSUBO M., MIYAKE T., NAKATA H., KINOSHITA F., YAMAGUCHI H.

電気学会研究会資料. ED, 放電研究会 2010 ( 60 ) 97 - 100 2010年11月

記述言語：日本語掲載種別：研究論文（学術雑誌）

Characteristics of Deteriorated ZnO Elements with Stripe-shaped Destruction Trace 査読あり

S. Miyazaki, T. Sakoda, M. Otsubo, T. Miyake, H. Nakata, F. Kinoshita

15th Asian Conference on Electrical Discharge 74 - 77 2010年11月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Characteristics of Deteriorated ZnO Elements with Stripe-shaped Destruction Trace 査読あり

S. Miyazaki, T. Sakoda, M. Otsubo, T. Miyake, H. Nakata, F. Kinoshita

15th Asian Conference on Electrical Discharge 74 - 77 2010年11月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Study on Insulation Degradation Difference between AC and DC Applications 査読あり

Takuma Miyake, Yuya Seo, Tatsuya Sakoda, Masahisa Otsubo, Tomikazu Anjiki

15th Asian Conference on Electrical Discharge 62 - 65 2010年11月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Investigation of Partial Discharge Location at Joint Section of XLPE Cable Using Acoustic Emission Technique 査読あり

J. M. Nainggolan, Toshihiko Nakashima, Tatsuya Sakoda, Masahisa Otsubo, Satoshi Kurihara, Shinya Nagasato

15th Asian Conference on Electrical Discharge 30 - 33 2010年11月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Relationship between Leakage Current and Pollution Deposits on the Surface of Polymeric Insulator 査読あり

Takuma Miyake, Yuya Seo, Tatsuya Sakoda, Masahisa Otsubo

Institute of Electrical Engineers of Japan Transactions on Electrical and Electronic Engineering 130 ( 11 ) 1009 - 1012 2010年11月

記述言語：英語掲載種別：研究論文（学術雑誌）

Comparison of Degradation Phenomena on Silicone Rubbers Eroded by DC and AC Discharges 査読あり

Daiki Shiibara, Yoshihiro Arata, Tatsuya Sakoda, Masahisa Otsubo, Tomikazu Anjiki

Institute of Electrical Engineers of Japan Transactions on Electrical and Electronic Engineering 130 ( 11 ) 1009 - 1012 2010年11月

記述言語：英語掲載種別：研究論文（学術雑誌）

Proposal of Multi-pass Laser Spectroscopic Technique for Diagnosing Atmospheric Pressure Discharge Plasmas 査読あり

Tatsuya Sakoda, Mark Bowden

Institute of Electrical Engineers of Japan Transactions on Electrical and Electronic Engineering 130 ( 11 ) 1026 - 1030 2010年11月

記述言語：英語掲載種別：研究論文（学術雑誌）

Studies on Acoustic Emission Signals Detected in an Oil-immersed Pole Transformer 査読あり

Takuya Yamamoto, Toshihiko Nakashima, Tatsuya Sakoda, Masahisa Otsubo, Satoshi Kurihara, Shinya Nagasato, Takayoshi Yarimitsu

Institute of Electrical Engineers of Japan Transactions on Electrical and Electronic Engineering 130 ( 11 ) 1031 - 1036 2010年11月

記述言語：英語掲載種別：研究論文（学術雑誌）

Etching Characteristics of Fabricated Grooves on Silicon Solar Cell Using Surface Discharge Plasma 査読あり

Toshiyuki Hamada, Tatsuya Sakoda

Institute of Electrical Engineers of Japan Transactions on Electrical and Electronic Engineering 130 ( 11 ) 999 - 1003 2010年11月

記述言語：英語掲載種別：研究論文（学術雑誌）

大気圧沿面放電プラズマを用いたマスクレスエッチング査読あり

濱田俊之, 水本貴之, 有村拓也, 迫田達也

電気学会論文誌A 130 ( 10 ) 907 - 912 2010年10月

記述言語：日本語掲載種別：研究論文（学術雑誌）

Location of Partial Discharge at Joint Section of XLPE Cable using Acoustic Emission Technique 査読あり

Jannus M. N., T. Nakashima, T. Sakoda, M. Otsubo, S. Kurihara, S. Nagasato, T. Yarimitsu

2010 Annual Report Conference on Electrical Insulation and Dielectric Phenomena 442 - 445 2010年10月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Diagnostics of Insulation Deterioration of Ethylene Propylene Rubber Using an Acoustic Emission Technique 査読あり

Tatsuya Sakoda, Toshihiko Nakashima, Masahisa Otsubo, Satoshi Kurihara, Shinya Nagasato, and Takayoshi Yarimitsu

IEEE Transactions on Dielectrics and Electrical Insulation 17 ( 4 ) 1242 - 1248 2010年8月

記述言語：英語掲載種別：研究論文（学術雑誌）

Diagnostics of insulation deterioration of ethylene propylene rubber using an acoustic emission technique

Sakoda T., Nakashima T., Nainggolan J., Otsubo M., Kurihara S., Nagasato S., Yarimitsu T.

IEEE Transactions on Dielectrics and Electrical Insulation 17 ( 4 ) 1242 - 1248 2010年8月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEE Transactions on Dielectrics and Electrical Insulation

The aim of this study is to investigate the relationship between lowering of the insulation performance of ethylene propylene rubber (EPR) used as a covering material of a cross-linked polyethylene (XLPE) cable and partial discharges (PDs) and to establish a diagnostic technique using an acoustic emission (AE) sensor. An accelerated deterioration test was carried out and then the detected AE signals were evaluated. The results showed that not only the intensity of the AE signal but also the number of counted AE signals of more than a critical value was very useful for diagnosing the EPR. We also proposed a diagnostic sequence using an AE technique. © 2010 IEEE.

DOI： 10.1109/TDEI.2010.5539696

超音波センサを用いた運転中水車発電機固定子巻線の部分放電分布と長期部分放電特性

Development of a grooving system for solar cell 査読あり

Takuya Arimura, Takayuki Mizumoto, Toshiyuki Hamada, and Tatsuya Sakoda

16 th International Conference on Electrical Engineering 2010年7月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

ポリマー材料への複合汚損の影響

三宅琢磨, 瀬尾裕也, 叶明文, 迫田達也, 大坪昌久

電気学会研究会資料. DEI, 誘電・絶縁材料研究会 2010 ( 34 ) 25 - 28 2010年1月

記述言語：日本語掲載種別：研究論文（学術雑誌）

ポリマー材料への複合汚損の影響

三宅琢磨, 瀬尾裕也, 叶明文, 迫田達也, 大坪昌久

電気学会研究会資料. ED, 放電研究会 2010 ( 10 ) 25 - 28 2010年1月

記述言語：日本語掲載種別：研究論文（学術雑誌）

ポリマー材料への複合汚損の影響

三宅琢磨, 瀬尾裕也, 叶明文, 迫田達也, 大坪昌久

電気学会研究会資料. HV, 高電圧研究会 2010 ( 10 ) 25 - 28 2010年1月

記述言語：日本語掲載種別：研究論文（学術雑誌）

金子正光, 日高徹, 三宅琢磨, 竹之内修, 迫田達也, 大坪昌久, 安藤美利, 杉原孝, 大岩根誠

電気学会研究会資料. ED, 放電研究会 2010 ( 10 ) 19 - 24 2010年1月

記述言語：日本語掲載種別：研究論文（学術雑誌）

超音波センサを用いた運転中水車発電機固定子巻線の部分放電分布と長期部分放電特性

金子正光, 日高徹, 三宅琢磨, 竹之内修, 迫田達也, 大坪昌久, 安藤美利, 杉原孝, 大岩根誠

電気学会研究会資料. DEI, 誘電・絶縁材料研究会 2010 ( 34 ) 19 - 24 2010年1月

記述言語：日本語掲載種別：研究論文（学術雑誌）

超音波センサを用いた運転中水車発電機固定子巻線の部分放電分布と長期部分放電特性

金子正光, 日高徹, 三宅琢磨, 竹之内修, 迫田達也, 大坪昌久, 安藤美利, 杉原孝, 大岩根誠

電気学会研究会資料. HV, 高電圧研究会 2010 ( 10 ) 19 - 24 2010年1月

記述言語：日本語掲載種別：研究論文（学術雑誌）

Examination of Maskless Etching Technique Using a Localized Surface Discharge Plasma

HAMADA Toshiyuki, SAKODA Tatsuya, OTSUBO Masahisa

IEEJ transactions on electrical and electronic engineering : official journal of the Institute of Electrical Engineering of Japan / = 電気学会 5 ( 1 ) 115 - 117 2010年1月

記述言語：日本語掲載種別：研究論文（学術雑誌）

Examination of Maskless Etching Technique Using a Localized Surface Discharge Plasma 査読あり

Toshiyuki Hamada, Tatsuya Sakoda, Masahisa Otsubo

IEEJ (Institute of Electrical Engineers of Japan) Transactions on Electrical and Electronic Engineering 5 ( 1 ) 115 - 117 2010年1月

記述言語：英語掲載種別：研究論文（学術雑誌）

Examination of maskless etching technique using a localized surface discharge plasma

Hamada T., Sakoda T., Otsubo M.

IEEJ Transactions on Electrical and Electronic Engineering 5 ( 1 ) 115 - 117 2010年1月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEJ Transactions on Electrical and Electronic Engineering

A maskless etching technique which is useful for solar cell manufacturing and microelectronics was examined using the localized surface discharge plasma at atmospheric pressure. Etchings were carried out on a crystalline silicon (Si) substrate and a silicon nitride (SiN) film coated on a Si substrate. Two-and three-dimensional etching profiles were investigated. Based on the results, etching rates and an etching mechanism were discussed. © 2010 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.

DOI： 10.1002/tee.20501

酸化亜鉛型避雷素子の筋状破壊機構の解明に関する研究

避雷素子表面における筋状破壊痕の形成過程の検討

宮崎哲司, 小林竜也, 迫田達也, 大坪昌久, 中田英宏, 木下文宏

電気関係学会九州支部連合大会講演論文集 2010 ( 0 ) 554 - 555 2010年

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：電気・情報関係学会九州支部連合大会委員会

雷から電力機器を保護するために設置されている配電用ZnO避雷器は、新規設備として設置された時点ではJEC-203避雷器で定められている避雷器の性能・特性を十分に満たしているが、課電ストレスや過大サージ等によりその特性は変化する。しかし、同劣化現象や経年劣化が考慮された限界性能については十分に明らかにされていない。また、現場で故障した避雷器内のZnO素子の様相として、ZnO 素子側面に筋状の破壊痕が確認されている。本研究では、交流課電中の雷インパルス電流重畳による配電用ギャップ付避雷器内ZnO素子の破壊様相の確認を目的として実験を行い、筋状破壊痕の形成過程の検討を行ったので報告する。

DOI： 10.11527/jceeek.2010.0.554.0

迫田達也, 宮川祐一郎, 宮崎哲司, 大坪昌久, 生田昌輝, 鎗光隆義

電気学会論文誌. B, 電力・エネルギー部門誌 = The transactions of the Institute of Electrical Engineers of Japan. B, A publication of Power and Energy Society 129 ( 12 ) 1593 - 1594 2009年12月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：The Institute of Electrical Engineers of Japan

To investigate a stripe-shaped destruction mechanism of a ZnO element used for a surge arrester, some breakdown tests were carried out. Applying a large impulse current to a ZnO element, a flashover trace was confirmed at the lateral face of the element. It was found that a trace of a stripe-shaped destruction was formed by a fact that AC current flew through the trace due to the flashover caused by a large impulse current.

DOI： 10.1541/ieejpes.129.1593

Studies on Non-thermal Atmospheric Pressure Plasma Process Conditions for Groove Formation on Silicon Nitride for Silicon Solar Cells 査読あり

Toshiyuki Hamada, Tatsuya Sakoda and Masahisa Otsubo

Materials Science in Semiconductor Processing 12 ( 3 ) 106 - 112 2009年12月

記述言語：英語掲載種別：研究論文（学術雑誌）

酸化亜鉛型避雷素子の筋状破壊機構の解明に関する研究査読あり

迫田達也, 宮川祐一郎, 宮崎哲司, 大坪昌久, 生田昌輝, 鎗光隆義

電気学会論文誌A 129 ( 12 ) 1593 - 1594 2009年12月

記述言語：日本語掲載種別：研究論文（学術雑誌）

Study on behavior of sputtered particles during surface discharges

Sakoda T.

Japanese Journal of Applied Physics 48 ( 10 Part 1 ) 1060031 - 1060034 2009年12月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Japanese Journal of Applied Physics

To investigate the behavior of Mg atoms sputtered from a MgO-coated electrode during plasma-display-panel (PDP)-like surface discharges formed on an electrode coated with dielectric materials, the relative density of sputtered Mg and dissociated Mg from MgO was measured by a laser induced fluorescence (LIF) technique. Additionally, optical emissions due to Mg and MgO were measured by optical emission spectroscopy (OES). The experimentally obtained results indicated that intermittently sputtered Mg atoms remained around the MgO-coated electrode for a long time and that Mg atoms also existed without recombining with O atoms. Additionally, numerical analyses were carried out using a two-dimensional plasma simulation code, and the results obtained were consistent with the experimental results. © 2009 The Japan Society of Applied Physics.

DOI： 10.1143/JJAP.48.106003

Application of Thermal Analysis for Clarification of Degradation Characteristics of Silicone Rubber Exposed to Partial Arc Discharge

HAJI Kenichi, HIRANO Kimitaka, SAKODA Tatsuya, OTSUBO Masahisa

IEEJ transactions on electrical and electronic engineering : official journal of the Institute of Electrical Engineering of Japan / = 電気学会 4 ( 6 ) 793 - 795 2009年11月

記述言語：日本語掲載種別：研究論文（学術雑誌）

Investigation of Stripe-shaped Destruction Mechanism of ZnO Element 査読あり

S. Miyazaki, T. Sakoda, M. Otsubo, M. Ikuta, and T. Yarimitsu

2009 Korea-Japan Joint Symposium on Electrical Discharge and High Voltage Engineering 318 - 321 2009年11月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Location of Partial Discharge at Joint Section of CV Cable Using Acoustic Emission Technique 査読あり

K. Sakamoto, T. Nakashima, T. Sakoda, M. Otsubo, T. Yarimitsu, S. Nagasato, and S. Kurihara

2009 Korea-Japan Joint Symposium on Electrical Discharge and High Voltage Engineering 314 - 317 2009年11月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Characteristics of Acoustic Emission Signals Detected in an Oil-immersed Pole Transformer 査読あり

M. Kurose, T. Yamamoto, T. Sakoda, and M. Otsubo

2009 Korea-Japan Joint Symposium on Electrical Discharge and High Voltage Engineering 310 - 313 2009年11月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Studies on Etching Characteristics of Fabricated Grooves on Silicon Solar Cell Using Surface Discharge 査読あり

T. Hamada, T. Sakoda, and M. Otsubo

2009 Korea-Japan Joint Symposium on Electrical Discharge and High Voltage Engineering 234 - 237 2009年11月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Proposal of Laser Raman Scattering Technique for Measurement of Molecular Density in Atmospheric Pressure Discharge 査読あり

Tatsuya Sakoda and Mark Bowden

2009 Korea-Japan Joint Symposium on Electrical Discharge and High Voltage Engineering 230 - 233 2009年11月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Characteristics of Distribution and Intensity for On-line Measurement Partial Discharge on Hydrogenerator Stator Windings using Acoustic Emission Sensors 査読あり

T. Kaneko, T. Hidaka, T. Miyake, M. Otsubo, T. Sakoda, O. Takenouchi, M. Andou

2009 Korea-Japan Joint Symposium on Electrical Discharge and High Voltage Engineering 87 - 90 2009年11月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Application of Thermal Analysis to Clarification of Degradation Characteristics of Silicone Rubber Exposed to Partial Arc Discharge 査読あり

Kenich Haji, Kimitaka Hirano, Tatsuya Sakoda, Masahisa Otsubo

IEEJ (Institute of Electrical Engineers of Japan) Trans. on Electrical and Electronic Engineering 4 ( 6 ) 793 - 795 2009年11月

記述言語：英語掲載種別：研究論文（学術雑誌）

Application of thermal analysis for clarification of degradation characteristics of silicone rubber exposed to partial arc discharge

Haji K., Hirano K., Sakoda T., Otsubo M.

IEEJ Transactions on Electrical and Electronic Engineering 4 ( 6 ) 793 - 795 2009年11月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEJ Transactions on Electrical and Electronic Engineering

To investigate the temperature distribution on the surface of a silicone rubber exposed to partial arc discharges, numerical analyses on thermal characteristics were carried out. The preliminary calculations indicated that there was no dependence of mesh and time step. The temperature on the specimen surface became high in the middle of the discharge gap while those at points of contact between an arc discharge and tips of glass-filter paper used as electrodes became low. The thermal diffusion from the points of contact between the arc discharge and the tips of glass-filter paper into electrolyte electrodes caused the temperature decrease at such points. © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.

DOI： 10.1002/tee.20483

Influence of electrification of droplet on hydrophobicity reduction of polymer material during a dynamic drop test

局部アーク放電に曝されたシリコーンゴムの熱解析

枦健一, 平野公孝, 迫田達也, 大坪昌久

電気設備学会誌 29 ( 10 ) 865 - 870 2009年10月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：電気設備学会

局部アーク放電に曝されたシリコーンゴムの熱解析査読あり

枦健一, 平野公孝, 迫田達也, 大坪昌久

電気設備学会論文誌 29 ( 10 ) 865 - 870 2009年10月

記述言語：日本語掲載種別：研究論文（学術雑誌）

Study on Behavior of Sputtered Particles during Surface Discharges 査読あり

Tatsuya Sakoda

Jpn. J. Appl. Phys 48 ( 10 ) 106003-1 - 106003-4 2009年10月

記述言語：英語掲載種別：研究論文（学術雑誌）

Dynamic Drop Testにおける帯電及び塩分による試料表面の撥水性への影響査読あり

椎原大輝, 荒田由浩, 枦健一, 三宅琢磨, 迫田達也, 大坪昌久

電気学会論文誌A 129 ( 9 ) 657 - 663 2009年9月

記述言語：英語掲載種別：研究論文（学術雑誌）

Ozone Generation Using Micro Barrier Discharge in Water 査読あり

Tatsuya Sakoda, Yoshihisa Matsuda, Seiji Baba

J. Plasma Fusion Res. SERIES 8 623 - 626 2009年8月

記述言語：英語掲載種別：研究論文（学術雑誌）

Studies on Discharge Mechanism of Micro-plasma Ozonizer Operated in Water 査読あり

Tatsuya Sakoda, Yoshihisa Matsuda, Yuji Tanaka, Seiji Baba, Junji Kijima, and Hideyuki Nakashima

IOA 19th World Congress & Exhibition 12-1-1 - 12-1-4 2009年8月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Haji K., Shiibara D., Arata Y., Sakoda T., Otsubo M.

IEEJ Transactions on Fundamentals and Materials 129 ( 5 ) 386 - 387 2009年7月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEJ Transactions on Fundamentals and Materials

The dynamic drop test was proposed as a method to evaluate hydrophobicity reduction of polymer materials. In this test, the formation change of a water channel was confirmed, and thereafter, the remained droplets and the dropped droplets on the sampled surface were repulsed each other. The distributions of electrification on the droplet and the sample surface were measured. The influence of the electrified droplet on the hydrophobicity reduction was examined. The results showed that the polarity on the sample surface changed by the dropped droplet, leading to the hydrophobicity loss. © 2009 The Institute of Electrical Engineers of Japan.

DOI： 10.1541/ieejfms.129.386

Plasma grooving system using atmospheric pressure surface discharge plasma

Studies on Si etching using atmospheric pressure surface discharge plasma 査読あり

T. Hamada, T. Sakoda, and M. Otsubo

Proc. of The 10th International Symposium on Sputtering and Plasma Processes 496 - 499 2009年7月

記述言語：英語掲載種別：研究論文（学術雑誌）

STUDIES ON ETCHINGS OF SILICON NITRIDE FILMS WITH VARIOUS FILM THICKNESS SILICON SUBSTRATES USING SURFACE DISCHARGE 査読あり

T. Hamada, T. Sakoda, and M. Otsubo

Proceedings of the 4th International Congress on Cold Atmospheric Pressure Plasmas 37 - 40 2009年6月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

STUDIES ON FORMATION OF ELECTRODE GROOVES FOR SOLAR CELL USING HIGH PRESSURE SURFACE DISCHARGE 査読あり

T. Hamada, T. Sakoda, and M. Otsubo

Proceedings of the 4th International Congress on Cold Atmospheric Pressure Plasmas 33 - 36 2009年6月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Hamada T., Sakoda T., Otsubo M.

Plasma Chemistry and Plasma Processing 29 ( 3 ) 197 - 204 2009年6月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Plasma Chemistry and Plasma Processing

To fabricate narrow front contact grooves on a single crystalline silicon solar cell, we carried out etching of a silicon nitride film on a silicon substrate using the surface discharge plasma operated at atmospheric pressure. The control of groove width by changing the discharge voltage (V d ) and the length of a back electrode (l) used for formation of the surface discharge was examined. It was found that narrower electrode grooves could be obtained when l was short. For the case of l = 2 mm, the narrowest groove of 116 μm was obtained at V d = 3.5 kV and the processing time (t e ) of 10 s. © 2009 Springer Science+Business Media, LLC.

DOI： 10.1007/s11090-009-9170-6

Studies on non-thermal atmospheric pressure plasma process conditions for groove formation on silicon nitride for silicon solar cells

Hamada T., Sakoda T., Otsubo M.

Materials Science in Semiconductor Processing 12 ( 3 ) 106 - 112 2009年6月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Materials Science in Semiconductor Processing

Fabrications of narrow electrode grooves for front electrodes on single crystalline silicon solar cells were examined using surface discharges, in which the electrode grooves were formed by etching a silicon nitride (SiN) film on substrates. The surface discharge could effectively etch the SiN film within 10 s and that a high etching rate more than 1800 nm/min was obtained. An optimum ratio of Ar gas, which was enough to maintain the formation of innumerable surface streamers, was 2.3 times larger than that of etching gas, and a short-term etching with the high discharge voltage was effective to narrow groove width. © 2009 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.mssp.2009.08.005

Characteristics of on-line and off-line partial discharge for hydrogenerator stator windings with AE sensor and CT sensor

Dynamic Drop Testにおけるポリマー材料の撥水性低下に及ぼす水滴の帯電の影響査読あり

枦健一, 椎原大輝, 荒田由浩, 迫田達也, 大坪昌久

電気学会論文誌A 129 ( 5 ) 386 - 387 2009年5月

記述言語：日本語掲載種別：研究論文（学術雑誌）

Plasma Grooving System Using Atmospheric Pressure Surface Discharge Plasma 査読あり

Toshiyuki Hamada, Tatsuya Sakoda, Masahisa Otsubo

Plasma Chemistry and Plasma Processing 29 197 - 204 2009年5月

記述言語：英語掲載種別：研究論文（学術雑誌）

AEセンサを用いた柱上変圧器内部の放電検出

山本拓也, 黒瀬充晴, 迫田達也, 大坪昌久, 鎗光隆義, 永里信也, 赤岩繁

電気関係学会九州支部連合大会講演論文集 2009 ( 0 ) 213 - 213 2009年

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：電気・情報関係学会九州支部連合大会委員会

現在、稼働期間が20 年を経過した変圧器が増加しているため、それらの経年劣化が危惧されている。柱上変圧器の場合、吸湿や腐食により絶縁材料である絶縁油や絶縁紙が劣化し、耐電圧強度や機械的強度が低下する。また、雷害による突発事故が起こると、巻線間で部分放電が発生し、巻線で焼損が起こる。瞬時の停電も許されない現在、如何に早期に微弱な異常現象を検出できるかが重要となっている。本研究では、部分放電の検出可能なAE法を用い、課電状態で絶縁劣化診断を行うことを目標としている。本報告では、油中に配置した模擬電極で放電を発生させ、放電に伴うAE信号の観測を行い、本手法における検出下限を検討した。

DOI： 10.11527/jceeek.2009.0.213.0

油入柱状変圧器内のAE波の伝播特性の評価

黒瀬充晴, 山本拓也, 迫田達也, 大坪昌久, 鑓光隆義, 永里信也, 赤岩繁

電気関係学会九州支部連合大会講演論文集 2009 ( 0 ) 214 - 214 2009年

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：電気・情報関係学会九州支部連合大会委員会

高度成長期に多量に導入された変圧器等の経年劣化が懸念されている中、低コストで安易な劣化診断技術の確立が急務となっている。雷により被害を受けた柱上変圧器内では巻線間で部分放電が発生して絶縁劣化が進行する。瞬時の停電も許されない現在、早期に微弱な異常現象を検出できるかが重要となっている。本研究では、部分放電の検出可能なAE法を用い、課電状態で絶縁劣化診断を行う事を目標としている。尚、変圧器内部は巻線や鉄心が存在するため、構成物がAE波の伝播にどのような影響を与えるか明らかにする必要がある。本報告では、実際の柱上変圧器を用い、油中で発生させた模擬放電パルスによるAE波の伝播特性を検討した結果を報告する。

DOI： 10.11527/jceeek.2009.0.214.0

Maeda I., Kaneko T., Takenouchi O., Miyake T., Sakoda T., Otsubo M., Fukumoto S., Tokumitsu A., Kai T., Ando M.

Proceedings of the International Symposium on Electrical Insulating Materials 577 - 580 2008年12月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Proceedings of the International Symposium on Electrical Insulating Materials

We pay attention to an insulation diagnosis technique of on-line hydrogenerator stator windings. On-line partial discharge monitoring and diagnosis of the insulation of hydrogenerator machines can be expected to reduce their maintenance costs. Therefore, we aim at development of the hybrid diagnostic method that ultrasonic wave signal occurring by partial discharge and leakage current flowing through neutral grounding cable of hydrogenerator. We set up many AE (acoustic emission) sensors to stator core and set up a CT (current transformer) sensor at neutral grounding cable of hydrogenerator. We measured AE signal and neutral grounding cable leakage current of hydrogenerator on stream. Furthermore, we set up measurement equipment in a hydrogenerator wing channel and measured AE signal and leakage current flowing at neutral grounding cable by partial discharge for a long term. In this paper, we have measured the relationship of on-line hydrogenerator out put and AE signal and leakage current flowing at neutral grounding cable. And, we have measured the AE signal and leakage current on the dielectric loss tangent test and partial discharge pulse at off-line test.

DOI： 10.1109/ISEIM.2008.4664533

Fundamental research on characteristics of hydrophobicity disappearance of silicone rubber surface in dynamic drop test

Shiibara D., Haji K., Sakoda T., Otsubo M.

Proceedings of the International Symposium on Electrical Insulating Materials 99 - 102 2008年12月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Proceedings of the International Symposium on Electrical Insulating Materials

A study on the development of deterioration / performance evaluation method for outdoor electric insulation of polymer materials is pushed forward now in the International Council on Large Electric Systems (CIGRE). The small scale docimasy (Dynamic Drop Test) which could evaluate a disappearance characteristic of the hydrophobicity easily was suggested [1] . This test method is to evaluate the loss of hydrophobicity to drop electrically-charged water droplets on the sample surface continuously. We applied this dynamic drop test (DDT) to polymer materials which differ in the amount of Alumina Tri-Hydrate (ATH) filled and investigated factors about the change of hydrophobicity, in which the surface roughness and difference of the quantity of migration of the low molecular weight (LMW) were examined.

DOI： 10.1109/ISEIM.2008.4664506

Influence of temperature variation on characteristics of ZnO elements

Miyakawa Y., Sakoda T., Otsubo M., Ikuta M.

Proceedings of the International Symposium on Electrical Insulating Materials 119 - 122 2008年12月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Proceedings of the International Symposium on Electrical Insulating Materials

Zinc oxide (ZnO) surge arresters with series gap are equipped to protect the electricity failure for power distribution systems. Although the ZnO surge arresters might have enough performances to protect the electricity failure when they were installed, the performance may decrease with the increase of the number of operation times and the time elapsed after the installation. The aim of this study is to investigate the effects of temperature variation on characteristics of ZnO elements. We first heated ZnO elements up to temperatures of 350K, 400K, 450K, and 500K, and then characteristics of V-t and 50% flashover voltage were examined. Next, in order to obtain V-I characteristic, the impulse current with 4/10μs-8kA was applied at each temperature. Finally, V-t characteristic and 50% flashover voltage for each temperature were evaluated, again. The results showed that temperature had an influence on V-I characteristics of ZnO surge arrester. Finally, V-t characteristics and 50% flashover voltages for each temperature were evaluated, again. The results showed that temperature had an influence on V-I characteristics of ZnO surge arrester.

DOI： 10.1109/ISEIM.2008.4664511

Relation between leakage current and NSDD on the surface of polymer insulator

Yamashita Y., Miyake T., Haji K., Sakoda T., Otsubo M.

Proceedings of the International Symposium on Electrical Insulating Materials 103 - 106 2008年12月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Proceedings of the International Symposium on Electrical Insulating Materials

This paper describes relation between leakage current and non solubility deposits density (NSDD) on the surface of a polymer insulator. Until now, we have studied outdoor polymer insulators in the coastal region in west Japan. In addition we proposed a novel on-line monitoring system, adopting differential techniques to separate the leakage current of outdoor polymer insulators into three components such as a conductive current, a corona discharge and a dry band arc discharge current. The results indicated that leakage current was influenced by NSDD rather than equipment solubility deposits density (ESDD). In this study, the test to clarity the above stated factor was performed.

DOI： 10.1109/ISEIM.2008.4664507

Characteristics evaluation of the partial arc discharge and the silicone rubber surface by dynamic drop test

高気圧沿面放電による太陽電池用電極溝の作製査読あり

濱田俊之, 荒川純一, 大坪昌久, 迫田達也

電気学会論文誌A 128-A ( 12 ) 733 - 739 2008年12月

記述言語：英語掲載種別：研究論文（学術雑誌）

Studies on Erosion of Silicone Rubber Exposed to Partial Arc Discharges 査読あり

Kenich Haji, Yong Zhu, Masahisa Otsubo, Tatsuya Sakoda

Polymer Degradation and Stability 93 ( 12 ) 2214 - 2221 2008年12月

記述言語：英語掲載種別：研究論文（学術雑誌）

Haji K., Shiibara D., Arata Y., Sakoda T., Otsubo M.

Annual Report - Conference on Electrical Insulation and Dielectric Phenomena, CEIDP 2008 272 - 275 2008年12月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Annual Report - Conference on Electrical Insulation and Dielectric Phenomena, CEIDP

This paper describes the results of experiments made to examine characteristics of hydrophobicity of ATH-filled silicone rubber specimen surface. As the examination method, we used a dynamic drop test (DDT), in which electrolyte solution droplet from an electrode continuously dropped on a sample and the ac voltage was supplied between electrodes. Hydrophobicity loss times of samples for various conductivities of electrolyte solutions were measured. The electric fields before and after hydrophobicity reduction were evaluated The results showed that the hydrophobicity loss time became short with the increase of conductivity and the electric field increased after hydrophobicity reduction. © 2008 IEEE.

DOI： 10.1109/CEIDP.2008.4772897

Fabrication of electrode groove on silicon solar cell using high-pressure surface discharge

Hamada T., Arakawa S., Otsubo M., Sakoda T.

IEEJ Transactions on Fundamentals and Materials 128 ( 12 ) 733 - 739 2008年12月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEJ Transactions on Fundamentals and Materials

We proposed a low-cost plasma process technique to fabricate narrower front electrode grooves on a single crystalline silicon solar cell, in which the surface discharge operated at high-pressure etched the silicon nitride film of 150 nm thickness on a silicon layer. The results showed that the surface discharge could effectively etch the silicon nitride film in a short time and that a high etching rate more than 3000 nm/min was obtained. The narrow and uniform grooves with the width of less than 70 μm were obtained when the pressure in a chamber, the back electrode length and the etching time were 152 kPa, 2 mm and 10 s respectively. The narrower electrode groove could be obtained when the back electrode length was short and the pressure was high. © 2008 The Institute of Electrical Engineers of Japan.

DOI： 10.1541/ieejfms.128.733

Studies on erosion of silicone rubber exposed to partial arc discharges

Haji K., Zhu Y., Otsubo M., Sakoda T.

Polymer Degradation and Stability 93 ( 12 ) 2214 - 2221 2008年12月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Polymer Degradation and Stability

The effect of electrolyte conductivity on the partial arc discharge development between two electrolyte electrodes on a silicone rubber sheet surface was investigated. Tests were executed by placing the salt-waterlogged glass-filter paper on a silicone rubber sheet to simulate a polluted electrolyte layer, and partial arc discharges with a constant current value of 10 mA were observed. It was found that the formation of an arc channel and a temperature distribution on the sample surface varied with the electrolyte conductivity. In addition, the relation between the electrolyte conductivity and the weight loss due to the heat erosion of specimens was also investigated by a 3D morphological observation and a simulated calculation. The partial arc discharge did significantly not influence on the sample surface erosion under serious polluted conditions. In contrast, the severest erosion appeared under the light pollution with comparatively lower conductivity of the electrolyte electrodes. © 2008.

DOI： 10.1016/j.polymdegradstab.2008.05.025

Studies of elastic waves in ethylene propylene rubber using acoustic emission sensor

Takaoka M., Sakoda T., Otsubo M., Akaiwa S., Iki M., Nakano S.

IEEJ Transactions on Fundamentals and Materials 128 ( 10 ) 641 - 646 2008年12月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEJ Transactions on Fundamentals and Materials

The aim of our study is to investigate the relationship between lowering of the insulation performance of cross-linked polyethylene (CV) cable and partial discharges (PDs) followed by the dielectric breakdown and to establish a diagnostic technique using an acoustic emission (AE) sensor. In this study, we focused on characterization of AE signals detected from ethylene propylene rubbers (EPRs) used as insulating materials of CV cables. Elastic waves with various frequencies were added to the surface of the EPR, and then characteristics of the detected AE signals due to the elastic waves propagated in the EPR were evaluated. We showed characteristics of Lamb waves whose low frequency components around 100 kHz were large and their small attenuation characteristics. © 2008 The Institute of Electrical Engineers of Japan.

DOI： 10.1541/ieejfms.128.641

Surface modification of carbon electrodes using an argon plasma

Etching of Silicon Nitride Using Atmospheric Pressure Surface Discharge Plasma 査読あり

T. HAMADA, M. OTSUBO, T. SAKODA

The 7th International Conference on Materials Processing for AMFT7005_1 - 3 2008年11月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Tashima D., Sakamoto A., Taniguchi M., Sakoda T., Otsubo M.

Vacuum 83 ( 3 ) 695 - 698 2008年10月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Vacuum

In this work, an activated carbon sheet was modified, to improve capacitance and energy density of electric double layer capacitors (EDLCs). Surfaces were treated with plasma for selected times of 1, 5, 10, 20, and 30 min. The plasma source was a DC glow discharge in argon gas. The pressure was 20 Pa and the distance between positive and negative electrodes was 20 mm. DC power was 70 W. The activated carbon sheets were set up so that the sheets were covered with the DC glow discharge. The results showed that plasma treatment led to roughening of the surface of the activated carbon sheets which became more pronounced for increased time. This was attributed to an increased surface area caused by argon plasma etching. For discharge times greater than 10 min, contamination from sputtered PTEE in the chamber appeared to have a smoothing effect and led to a reduction of the measured surface area. Capacitance of the EDLCs cells with the activated carbon sheets after 1 min plasma surface treatment was increased by 2% compared to EDLCs cells with the original activated carbon sheet. The results have shown that the modification by plasma treatment of activated carbon sheets is a suitable technique for EDLCs used in high current applications. © 2008 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.vacuum.2008.04.060

Development of novel ozonizer using micro-barrier discharges formed in water

Characteristics Evaluation of the Partial Arc Discharge and the Silicone Rubber Surface by Dynamic Drop Test 査読あり

Haji, Kenichi; Shiibara, Daiki; Otsubo, Masahisa, Sakoda Tatsuya, Yoshihiro Arata

2008 Annual Report Conference on Electrical Insulation Dielectric Phenomena 272 - 275 2008年10月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Surface Modification of Carbon Electrode using Argon Plasma 査読あり

D. Tashima, A. Sakamoto, M. Taniguchi, T. Sakoda, M. Otsubo

Vacuum 83 ( 3 ) 695 - 698 2008年10月

記述言語：英語掲載種別：研究論文（学術雑誌）

Development of Novel Ozonizer Using Micro-Barrier Discharges Formed in Water 査読あり

Tatsuya Sakoda, Yoshihisa Matsuda, Seiji Baba

Japanese Journal of Applied Physics 47 ( 10 ) 8030 - 8032 2008年10月

記述言語：英語掲載種別：研究論文（学術雑誌）

Sakoda T., Matsuda Y., Baba S.

Japanese Journal of Applied Physics 47 ( 10 PART 1 ) 8030 - 8032 2008年10月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Japanese Journal of Applied Physics

An ozonizer operating in water for the generation of ozone water was proposed. The key to ozone generation was the use of a Shirasu-porous-glass (SPG), which functioned in bubble supply and the formation of micro-barrier discharges. A mesh electrode was put on the SPG surface facing the gaseous phase side, and ac voltage was supplied to the electrode. Micro-barrier discharges were formed in micropores of the SPG, and bubbles formed in contact with the SPG surface facing the water phase side. The higher the applied ac voltage, the higher the uniformity of discharges and ozone concentration. © 2008 The Japan Society of Applied Physics.

DOI： 10.1143/JJAP.47.8030

Electrochemical properties of modified carbon electrodes for electric double layer capacitors

Tashima D., Sakamoto A., Taniguchi M., Sakoda T., Otsubo M.

Surface and Coatings Technology 202 ( 22-23 ) 5560 - 5563 2008年8月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Surface and Coatings Technology

To improve capacitance and energy density of electric double layer capacitors (EDLCs), plasma surface treatments were carried out on surface of activated carbon sheets, and optimal conditions for the treatment were discussed. Operating gas pressure of argon was 20 Pa, and activated carbon sheets were set up so that they were covered with the dc glow discharge at 70 W. Electrochemical properties, including cyclic voltammetry (CV) and cole-cole plot of EDLCs in organic electrolyte, were examined. The results showed that capacitance of the plasma-treated EDLC increased to 11% in comparison with that of untreated one. The enhancement in specific capacitance was mainly attributable to increasing of ratio of surface area of the activated carbon sheets. © 2008.

DOI： 10.1016/j.surfcoat.2008.06.147

Optimization of convex electrode geometry for surface discharge used for fabrication of the electrode groove on solar cells

Hamada T., Arakawa S., Sakoda T., Otsubo M., Matsui K., Nagasawa K.

Surface and Coatings Technology 202 ( 22-23 ) 5405 - 5409 2008年8月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Surface and Coatings Technology

A low-cost plasma process technique for fabrication of electrode grooves on solar cells, in which the surface discharge operated at atmospheric pressure etched the silicon nitride film, was examined. Three kinds of dielectric electrodes of similar quality but of different shape and thickness were used, and the optimum electrode geometry was discussed. It was found that the suppression of the diffusion of radical species was a key to narrow the groove width and that a short term etching was necessary when the streamer length was long due to the geometry of the dielectric electrode. © 2008.

DOI： 10.1016/j.surfcoat.2008.06.167

音響・電気的測定法を用いた運転中水車発電機の長期部分放電特性

平谷龍一, 前田育也, 金子正光, 辻利則, 竹之内修, 大坪昌久, 本田親久, 迫田達也, 福元晋, 徳満明博, 甲斐稔康, 安藤美利

宮崎大學工學部紀要 37 163 - 168 2008年8月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：宮崎大学

Recently, many equipments in power facilities, especially hydrogenerators installed at high-growth period of the economy will pass over about 40 years, and is seeing an updating term. However, under the recent economically severe condition of social environment, there is a strong demand to use these equipments to a life limit by understanding about their performance. Furthermore, in order to raise the utilization rates of the production facilities, the diagnosis at an on-line condition is also desired. In order to meet the requests, it is required to understand as correctly as possible the performance of these equipments under the on-line condition.###In order to build up the insulation deterioration diagnosis of the on-line hydrogenerator stator windings, we measured the AE signal and the leakage current of neutral point grounding line attended with partial discharge for two hydrogenerators using with the hybrid insulation deterioration diagnosis device. We put in the device at the two hydrogenerators, and we measured the AE signal and the leakage current of neutral point grounding line for a long term, respectively.

Visualization of sound field with uniform phase distribution using laser beam microphone coupled with computerized tomography method

Sakoda T., Sonoda Y.

Acoustical Science and Technology 29 ( 4 ) 295 - 299 2008年7月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Acoustical Science and Technology

An initial step in evaluating the possibility of applying the LBM-CT method to a general complex field has evaluated whether the Laser Beam Microphone (LBM) technique coupled with Computerized Tomography (CT), can reconstruct and visualize the phase distribution of a complex sound field. The study has verified the workability of the LBM-CT method for the visualization of only the amplitude distribution of the sound field. A measured sound field was with almost uniform phase distribution in the cross section including the probing laser beam. The measurement of diffraction signals caused by the sound waves with a frequency of 20 KHz was performed and the reconstruction of the sound waves was examined using CT method. The study compared the reconstructed distribution of the sound pressure with those measured using an electrostatic microphone (EM) and confirmed the feasibility of the LBM-CT method for visualizing a uniform-phase distribution acoustic field.

DOI： 10.1250/ast.29.295

ダイナミックドロップテストにおけるシリコーンゴム表面の撥水性消失特性

Optimization of Convex Electrode Geometry for Surface Discharge used for Fabrication of the Electrode Groove on Solar Cells 査読あり

T. Hamada, T. Sakoda, M. Otsubo, K. Matsui and K. Nagasawa

Surface & Coating Technology 202 5405 - 5409 2008年6月

記述言語：英語掲載種別：研究論文（学術雑誌）

椎原大輝, 枦健一, 山下洋平, 三宅琢磨, 迫田達也, 大坪昌久

電気学会研究会資料. ED, 放電研究会 2008 ( 1 ) 29 - 34 2008年1月

記述言語：日本語掲載種別：研究論文（学術雑誌）

カウント数と周期ノイズ検出法を用いたがいし放電音の観測

西田圭助, 坂本孝基, 辻利則, 迫田達也, 大坪昌久, 本田親久

電気学会研究会資料. ED, 放電研究会 2008 ( 1 ) 41 - 44 2008年1月

記述言語：日本語掲載種別：研究論文（学術雑誌）

碍子表面の汚損堆積物が漏れ電流に与える影響の検討

山下洋平, 枦健一, 椎原大輝, 三宅琢磨, 迫田達也, 大坪昌久

電気学会研究会資料. ED, 放電研究会 2008 ( 1 ) 23 - 27 2008年1月

記述言語：日本語掲載種別：研究論文（学術雑誌）

絶縁ゴムの部分放電劣化に伴うAE信号の特性解析

高岡正成, 大城泰士, 百田泰久, 迫田達也, 大坪昌久, 市場康弘, 吉満和寛, 壱岐正利, 中野重治

電気学会研究会資料. ED, 放電研究会 2008 ( 1 ) 19 - 22 2008年1月

記述言語：日本語掲載種別：研究論文（学術雑誌）

Relation between dry band arc discharge development and erosion shape on the silicone rubber

Haji K., Zhu Y., Otsubo M., Sakoda T., Honda C.

Annual Report - Conference on Electrical Insulation and Dielectric Phenomena, CEIDP 2007 Vol.1 312 - 315 2007年12月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Annual Report - Conference on Electrical Insulation and Dielectric Phenomena, CEIDP

This paper describes the results of experiments made to examine the erosion of alumina trihydrate filled silicone rubber exposed to dry band arc discharges. The eroded shape and weight loss of each sample, caused by the dry band arc discharges, were evaluated. The eroded amounts of the silicone rubbers aged in dry band arc discharge by changing in electrolyte conductivity were measured. The average weight loss was also experimentally obtained. The weight loss was compared with that calculated by considering the eroded shape and the density of the rubber aged in different conditions. Based on the results, the relation between the erosion shape and the dry band arc discharge was discussed. ©2007 IEEE.

DOI： 10.1109/CEIDP.2007.4451511

音響・電気信号ハイブリッド検出による運転中水車発電機の部分放電特性

藤井太志, 平谷龍一, 辻利則, 金子正光, 竹之内修, 迫田達也, 大坪昌久, 本田親久, 甲斐稔康, 福元晋, 徳光明博, 安藤美利

宮崎大學工學部紀要 36 109 - 114 2007年8月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：宮崎大学

Establishment of condition based maintenance for hydrogenerator is very im portant for monitoring the insulation of stator windings. The partial discharge testing is a promising method of condition monitoring of hydrogenerator stator winding insulation. Therefore, the on-line partial discharge testing has been used to provide useful information to diagnose and monitor the integrity of stator winding insulation of many hydrogenerators. In this paper, We have developed a method for diagnosing the insulation deterioration of hydrogenerator stator windings by hybrid detection using acoustic and electrical measurement methods. Using this developed system, We measured the AE signals and leakage current on on-line hydrogenerator stator windings. Additionally, We investigated the relationship of the intensity and delay time of AE signal in each the AE sensor position for long term.

多孔質ガラス膜を用いたオゾナイザー開発に関する基礎研究

岡村健, 森本琢磨, 三宅琢磨, 迫田達也, 馬場誠二

宮崎大學工學部紀要 36 151 - 156 2007年8月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：宮崎大学

As ozone has strong oxidation power and it is quickly changed into oxygen due to its short life time, it is harmless technology of water treatment for the environment. A bubbling technique is favorable to dissolve ozone in water, however, the dissolution efficiency is low. Therefore, we proposed a novel ozone generator which can effectively dissolve ozone through the porous glass film. Ozone was formed in the porous film and dissolved in water without bubbling.### In this study, a new type ozone generator with the porous glass film was first constructed. Next, characteristics of the generator were investigated.### It was found that the new type generator was able to be applied to water treatment.

レーザ誘起蛍光法を用いたMgO保護膜の劣化過程の解明(2)

池田一貴, 高木伸也, 迫田達也, 大坪昌久, 本田親久

電気学会研究会資料. ED, 放電研究会 2007 ( 13 ) 1 - 4 2007年1月

記述言語：日本語掲載種別：研究論文（学術雑誌）

Dynamic Drop Testによるポリマー碍子材料の性能評価

椎原大輝, 枦健一, 三宅琢磨, 迫田達也, 大坪昌久

電気関係学会九州支部連合大会講演論文集 2007 ( 0 ) 246 - 246 2007年

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：電気・情報関係学会九州支部連合大会委員会

DOI： 10.11527/jceeek.2007.0.246.0

PDP模擬電極上の表面放電によるスパッタMg粒子の挙動解析

高木伸也, 田中裕二, 迫田達也, 本田親久

電気関係学会九州支部連合大会講演論文集 2007 ( 0 ) 472 - 472 2007年

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：電気・情報関係学会九州支部連合大会委員会

DOI： 10.11527/jceeek.2007.0.472.0

電気的・音響的測定法による実機水車発電機固定子巻線と室内実験の部分放電特性

前田育也, 金子正光, 竹之内修, 迫田達也, 大坪昌久, 本田親久, 福元晋, 徳満明博, 甲斐稔康, 安藤美利

電気関係学会九州支部連合大会講演論文集 2007 ( 0 ) 256 - 256 2007年

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：電気・情報関係学会九州支部連合大会委員会

DOI： 10.11527/jceeek.2007.0.256.0

高気圧沿面放電による窒化シリコン膜のエッチング

荒川純一, 濱田俊之, 六田朋美, 近藤龍治, 迫田達也

電気関係学会九州支部連合大会講演論文集 2007 ( 0 ) 473 - 473 2007年

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：電気・情報関係学会九州支部連合大会委員会

DOI： 10.11527/jceeek.2007.0.473.0

ケーブル劣化診断用AE検出システムの開発

高岡正成, 百田泰久, 大城泰士, 迫田達也, 大坪昌久, 吉満和寛, 壱岐正利, 中野重治

電気関係学会九州支部連合大会講演論文集 2007 ( 0 ) 255 - 255 2007年

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：電気・情報関係学会九州支部連合大会委員会

DOI： 10.11527/jceeek.2007.0.255.0

誘電体バリア放電を用いた電気二重層キャパシタ用カーボン電極の表面改質

江崎正敏, 高田真司, 田島大輔, 迫田達也, 大坪昌久

電気関係学会九州支部連合大会講演論文集 2007 ( 0 ) 461 - 461 2007年

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：電気・情報関係学会九州支部連合大会委員会

DOI： 10.11527/jceeek.2007.0.461.0

曝露試験ポリマーがいしの汚損堆積物が漏れ電流に与える影響

山下洋平, 枦健一, 椎原大輝, 三宅琢磨, 迫田達也, 大坪昌久

電気関係学会九州支部連合大会講演論文集 2007 ( 0 ) 146 - 146 2007年

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：電気・情報関係学会九州支部連合大会委員会

DOI： 10.11527/jceeek.2007.0.146.0

放電ギャップ内の微小気泡を介した放電の生成

松田芳久, 城戸慎太郎, 池田幸一郎, 迫田達也, 馬場誠二, 久木崎雅人

電気関係学会九州支部連合大会講演論文集 2007 ( 0 ) 389 - 389 2007年

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：電気・情報関係学会九州支部連合大会委員会

DOI： 10.11527/jceeek.2007.0.389.0

メタルハライドランプの遅相形点灯回路における高調波電流の低減と発光効率の評価

叶明文, 黒住正明, 迫田達也, 大坪昌久

電気関係学会九州支部連合大会講演論文集 2007 ( 0 ) 249 - 249 2007年

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：電気・情報関係学会九州支部連合大会委員会

DOI： 10.11527/jceeek.2007.0.249.0

RF PE-CVD characteristics for the growth of carbon nanotubes in a CH <inf>4</inf>/N<inf>2</inf> mixed gas

Sung Y., Yuji T., Sakoda T.

Proceedings - International Symposium on Discharges and Electrical Insulation in Vacuum, ISDEIV 2 600 - 603 2006年12月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Proceedings - International Symposium on Discharges and Electrical Insulation in Vacuum, ISDEIV

Characteristics of radio-frequency (RF) plasma-enhanced vapor deposition (PE-CVD) for the growth of carbon nanotubes (CNTs) in a CH,/N 2 mixed gas were investigated through characterization of the prepared CNTs and a numerical simulation. The preparation of the CNTs was performed by the single chamber plasma process where the catalyst sputter deposition using a capacitively coupled plasma (CCP) and the PE-CVD using a inductively coupled plasma were carried out in the same discharge chamber. The plasma chemistry which is useful for optimizing preparation conditions was evaluated using the numerical code which could calculate the temporal evolution of particle densities in the plasma. The results showed the usefulness of the single chamber process system. It was also found that CH4, HCN and C 2 H 6 radicals mainly contributed to the growth of CNTs. © 2006 IEEE.

DOI： 10.1109/DEIV.2006.357373

Monitoring of an MgO degradation in AC plasma display panel using multivariate analysis method

Sung Y., Ikeda K., Honda C., Sakoda T.

Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers 45 ( 10 B ) 8104 - 8108 2006年10月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers

To investigate the degradation process of the MgO layer in a plasma display panel (PDP) discharge cell, measurements of Mg particles emitted from the surface of the MgO layer during an ac-PDP discharge were performed using the laser-induced fluorescence (LIF) technique. The spatial distribution of LIF signals agreed with the erosion pattern of the surface of the MgO layer. It was also found that a Mahalanobis-Taguchi system (MTS) where multi-dimensional measured values (e.g., discharge current, voltage, and luminance) were consolidated and converted into a standard was useful for the quantitative evaluation of the degradation degree of PDP discharge cells. © 2006 The Japan Society of Applied Physics.

DOI： 10.1143/JJAP.45.8104

Selective etching of silicon nitride film on single crystalline silicon solar cell using intensive surface discharge

Sakoda T., Hamada T., Matsukuma K., Herai H., Matsui K., Nagasawa K.

Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers 45 ( 5 A ) 3992 - 3993 2006年5月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers

A new etching technique, which is useful for the formation of electrode grooves for finger and busber electrodes on solar cells, was examined using a surface discharge at atmospheric pressure. A silicon nitride film was etched along boundary lines between discharge electrodes covered with a dielectric layer and the film. It was found that intensive surface streamers play an essential role in the etching of the film and that a high etching rate more than 150nm/min could be obtained. © 2006 The Japan Society of Applied Physics.

DOI： 10.1143/JJAP.45.3992

Plasma treatment on electrode surfaces of bifacial silicon solar cells

Sakoda T., Sung Y., Matsukuma K.

Solar Energy Materials and Solar Cells 90 ( 7-8 ) 1089 - 1097 2006年5月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Solar Energy Materials and Solar Cells

To lower the fabrication cost of silicon solar cells, a surface treatment using a dielectric barrier discharge (DBD) instead of a wet cleaning technique was examined on electrode surfaces on silicon solar cells. The fill factor obtained through measuring current-voltage characteristics was evaluated, and the treated surface state was characterized by energy-dispersive X-ray. It was found that the DBD effectively activated the electrode surface and the surface treatment on finger electrodes contributed greatly to improve the fill factor. © 2005 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.solmat.2005.06.008

Measurement of low-frequency ultrasonic wave in water using an acoustic fiber sensor

Sakoda T., Sonoda Y.

IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control 53 ( 4 ) 761 - 766 2006年4月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control

An acoustic fiber sensor for measurement of ultrasonic waves, which used the approximate Raman-Nath diffraction effect where light diffraction waves were generated in an optical fiber by strain due to the ultrasonic waves, was proposed and examined. In order to characterize the acoustic fiber sensor as a basic study, measurements of low-frequency ultrasonic waves in water were examined using a step index fiber operating as a detection sensor. The results showed that characteristics of detected signals agreed with the theoretical prediction based on Fraunhofer diffraction. This indicates that our proposed fiber sensor can be used for the detection of low-frequency ultrasonic waves as well as the transmission of light diffraction signals. © 2006 IEEE.

DOI： 10.1109/TUFFC.2006.1611035

Optimum conditions for ozone formation in a micro dielectric barrier discharge

Sung Y., Sakoda T.

Surface and Coatings Technology 197 ( 2-3 ) 148 - 153 2005年7月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Surface and Coatings Technology

Micro-dielectric barrier discharge has attracted attention as a practical solution to realize an atmospheric pressure glow discharge process suitable for the surface treatments including ozone generation. In order to investigate the optimum conditions for the effective ozone formation in a micro-dielectric barrier discharge, measurements of ozone concentration were carried out for various conditions such as the gap length, the dielectric material and the operating gas. It was found that the optimum discharge conditions extremely differed in the kinds of the operating gases and the dielectric materials. In dry air, the dielectric material with the low dielectric constant and thermal conductivity, which might contribute the restriction of the gas temperature rise in the discharge region, was effective to obtain the high ozone yield and concentration. The optimum gap length was considered to be in the range of 0.6-0.8 mm. In oxygen, using a quartz glass disk as the dielectric material, the required condition to obtain the high ozone yield and concentration was expanded. © 2004 Published by Elsevier B.V.

DOI： 10.1016/j.surfcoat.2004.09.031

Additional Plasma Surface Texturing for Single-Crystalline Silicon Solar Cells Using Dielectric Barrier Discharge

Sakoda Tatsuya, Matsukuma Kunihiro, Sung Youl-Moon, Otsubo Kouji, Tahara Minoru, Nakashima Yoshihiro

Japanese Journal of Applied Physics 44 ( 4 ) 1730 - 1731 2005年

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：公益社団法人応用物理学会

To reduce the light reflection from surfaces of single-crystalline solar cells, a new surface texturing technique using a dielectric barrier discharge was proposed and examined on wet-textured surfaces of single-crystalline Si substrates. Minute uneven structures were additionally formed on the entire area of a wet-textured surface of pyramid-like shape. When the discharge voltage was 3.5 kV, the reflectance was less than 8% at wavelengths from 400 to 1000 nm and showed a minimum of 5.3% at 520 nm.

DOI： 10.1143/JJAP.44.1730

Activation of electrode surface on silicon solar cell using dielectric barrier discharge

Sakoda T., Matsukuma K., Araki I., Sung Y., Terakawa T., Furukawa K.

Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers 43 ( 6 A ) 3275 - 3280 2004年6月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers

To yield an activated electrode surface on a silicon solar cell, a surface treatment was examined using a dielectric barrier discharge instead of a wet cleaning technique. After the dry cleaning process using the dielectric barrier discharge, the surface state and the fill factor of the solar cell were evaluated. The results showed that the dielectric barrier discharge plasma could effectively activate the electrode surface of the solar cell in a relatively short time. Additionally, it was found that the surface treatment on finger electrodes played an essential role in the improvement of the fill factor.

Activation of Electrode Surface on Silicon Solar Cell Using Dielectric Barrier Discharge

Sakoda Tatsuya, Matsukuma Kunihiro, Araki Ichiro, Sung Youl-Moon, Terakawa Takeshi, Furukawa Katsuhiko

Japanese Journal of Applied Physics 43 ( 6 ) 3275 - 3280 2004年

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：公益社団法人応用物理学会

DOI： 10.1143/JJAP.43.3275

Evaluation of Insulation Performance of Polymeric Surface using a Novel Separation Technique of Leakage Current

Otsubo M., Hashiguchi T., Honda C., Takenouchi O., Sakoda T., Hashimoto Y.

IEEE Transactions on Dielectrics and Electrical Insulation 10 ( 6 ) 1053 - 1060 2003年12月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEE Transactions on Dielectrics and Electrical Insulation

This paper describes a novel method to separate the leakage current, obtained in polymeric materials during a salt fog aging test, into three components of conductive current, corona discharge current and dry band arc discharge current. First, we investigated that the relationship between optical emissions due to discharges and a leakage current. Based on experimentally defined discharge types, the separation of the leakage current was carried out. Finally, the polymer surface was analyzed using an electron spectroscopy for chemical analysis (ESCA), and the change in the polymeric constituents was evaluated. The results showed that the cumulative charges due to the dry band arc discharge and the corona discharge to the total charge were about 20 and 10%, respectively. It was also found that a high temperature vulcanized (HTV) silicone rubber could retain its insulation performance better than a room temperature vulcanized (RTV).

DOI： 10.1109/TDEI.2003.1255783

Transmission and detection of light diffraction signal by low-frequency ultrasonic wave

Sakoda T., Sonoda Y.

Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers 42 ( 9 A ) 5821 - 5825 2003年9月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers

Measurement of low-frequency ultrasonic waves in water was examined by the light diffraction effect of a visible laser beam. This laser beam was much narrower than the ultrasonic wavelength. Characteristics of detected signals agreed well with the theoretical prediction based on Fraunhofer diffraction. As shown in the results, light diffraction waves transmitted through a polarization-maintaining fiber could be detected correctly. The results enable us to construct a novel optical fiber sensor which will be used for the detection of low-frequency ultrasonic waves as well as the transmission of light diffraction signals.

Spatial distribution of charged particles in a magnetic neutral loop discharge etcher: Experimental results and numerical simulations

Sung Y., Sakoda T.

Surface and Coatings Technology 166 ( 2-3 ) 135 - 140 2003年3月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Surface and Coatings Technology

This paper reports a result of rather sophisticated measurement in a magnetic neutral loop discharge (NLD) etcher system. The spatial profiles of electron temperature T e and density n e were measured for an extended region including the downstream of the source using laser Thomson scattering technique. Also, based on these profiles and ion current density measured by a double probe, experimental and numerical investigation for the entire structure of electron behavior was performed. The results showed that the high-density plasma produced around the magnetic neutral loop (NL) is transferred from the NL region to the downstream region along magnetic force lines. © 2002 Elsevier Science B.V. All rights reserved.

DOI： 10.1016/S0257-8972(02)00778-8

Observation of copper atoms behavior in a vacuum arc discharge using laser spectroscopy

Sung Y., Hayashi Y., Okraku-Yirenkyi Y., Otsubo M., Honda C., Sakoda T.

Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films 21 ( 1 ) 180 - 185 2003年1月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films

The behavior of Cu particles emitted from the electrode designed as an imitation of a vacuum valve of the vacuum circuit breaker (VCB) was observed using the laser induced fluorescence (LIF) technique with a filtered camera that could detect the optical radiation due to Cu particles in the excited state. From the results of the LIF measurements, it was confirmed that Cu particles were emitted and distributed between electrodes even after the discharge finished. In addition, the density of Cu particles was high around the anode region.

DOI： 10.1116/1.1531141

Studies on electron behaviors at downstream region of a neutral loop discharge plasma

Sakoda T., Sung Y.

Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films 20 ( 6 ) 1964 - 1968 2002年11月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films

The measurements of ion current density, electron density and electron temperature at the plasma downstream region in a neutral loop discharge (NLD) plasma were performed. It was concluded that the obtained profiles of the ion current density, electron temperature and electron density at the downstream and throughout the intermediate regions were the mirror of profiles at the plasma source regions. The quantitative evaluation phase was included after the Thomson scattering measurements.

DOI： 10.1116/1.1513644

Two-dimensional modeling and optimization of a neutral loop discharge etcher in an argon plasma

Okraku-Yirenkyi Y., Sung Y., Otsubo M., Honda C., Sakoda T.

Surface and Coatings Technology 149 ( 2-3 ) 185 - 191 2002年1月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Surface and Coatings Technology

In order to ascertain the optimal conditions for plasma generation in a magnetic neutral loop discharge (NLD), experiments were conducted to determine the electron temperature, T c and electron density, n c distributions around the NL. For the plasma production efficiency, the ion flux density measurements were done. The experimental results were examined by using a model that included effects of a three-dimensional electromagnetic field with spatial decay of the RF electric field, and the limitation of the spatial extent of the electron motion and collision effect. From the experiments and modeling of the electron behavior, it was found that NLD plasma possesses the electron temperature T e and density n e peaks around the NL and there existed an optimum value of the magnetic field gradient for efficient plasma production. © 2002 Elsevier Science B.V. All rights reserved.

DOI： 10.1016/S0257-8972(01)01440-2

Investigation of the conditions required for the formation of a magnetic neutral loop discharge plasma

Sakoda T., Okraku-Yirenkyi Y., Sung Y., Otsubo M., Honda C.

Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers 40 ( 11 ) 6607 - 6612 2001年11月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers

In order to reveal the conditions required for the formation of a neutral loop discharge (NLD) plasma, distributions of excited atoms that are closely related to the distributions of the ionization rates were measured under various discharge conditions. Measurements of the distributions of these excited atoms were performed by laser induced fluorescence spectroscopy and optical emission spectroscopy. It was found that the results of these measurements were consistent with the theoretically predicted dependencies of electron heating on the magnetic field strength, the radio frequency (RF) electric field, and the frequency of the RF source. In addition, it was shown that the effects of electron-neutral collisions and of the finite size of the device set limitations on the formation of the NLD plasma.

Prebreakdown phenomena and formation processes of low-pressure glow discharges in Ar, Ar/N2 and Ar/O2 mixtures

Sakoda T., Okraku-Yirenkyi Y., Sung Y., Otsubo M., Honda C.

Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers 40 ( 11 ) 6600 - 6606 2001年11月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers

In this research, both the prebreakdown phenomena and the transient processes from the prebreakdown phenomena to the glow discharge in low-pressure Ar gas, Ar/N 2 and Ar/O 2 mixtures were investigated by electrical and optical methods. The prebreakdown phenomenon in the Ar/N 2 mixture was similar to that of Ar gas, and a pulseless component has been observed. The prebreakdown phenomenon in the Ar/O 2 mixture differed from those in the Ar gas and Ar/N 2 mixture, and formed a pulse discharge. Thus, the prebreakdown phenomenon in the Ar gas has been changed to pulse discharge by mixing a small amount of O 2 gas which played an important role in the formation of pulse discharge.

Experimental and numerical analyses of electron temperature and density distributions in a magnetic neutral loop discharge plasma

Okraku-Yirenkyi Y., Sung Y., Otsubo M., Honda C., Sakoda T.

Journal of Vacuum Science and Technology, Part A: Vacuum, Surfaces and Films 19 ( 5 ) 2590 - 2595 2001年9月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Vacuum Science and Technology, Part A: Vacuum, Surfaces and Films

The numerical analysis of electron temperature and density distributions in a magnetic neutral loop discharge plasma (NLD) was carried out. The electron behaviour was analyzed taking into consideration several factors like magnetic field, antenna position and chamber walls. It was found that electrons were trapped in the region towards neutral discharge (NL) due to mirror fields and caused a peak in electron density.

DOI： 10.1116/1.1397467

Diagnostics of transformer oil by elastic waves

Sakoda T., Nieda H., Ando K.

Electrical Engineering in Japan (English translation of Denki Gakkai Ronbunshi) 135 ( 1 ) 1 - 7 2001年4月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Electrical Engineering in Japan (English translation of Denki Gakkai Ronbunshi)

In the diagnostics of oil-immersed transformers, a chemical analysis of generated gases in the oil is generally performed, evaluating the kinds of gases and their quantities. This method, however, involves numerous procedures and is difficult to use in the field to diagnose the deterioration of oil. Considering the current state of the advanced information society, no deterioration in power apparatus should be permitted and the diagnosis of deterioration must be performed reliably while the equipment is energized. Therefore, we attempted to diagnose insulation oil based on analyses of elastic waves produced by a pulse discharge in the oil. This technique uses the behavior of elastic waves in liquid, in which an incident wave causes a high-frequency oscillation component with increasing gas content. In this investigation, elastic waves were detected on the outside surface of an oil tank at gas concentrations of 0 to 10%. The detected waves were analyzed by the fast Fourier transform. It was found that frequency spectra of 400 to 1000 kHz were increasingly evident when the gas concentration in oil was higher than ∼5%. This indicates that our new technique is useful for the diagnostics of oil-immersed transformers using the oscillation behavior of elastic waves produced by bubbles in oil. © 2001 Scripta Technica.

DOI： 10.1002/1520-6416(20010415)135:1<1::AID-EEJ1>3.0.CO;2-L

Characteristics of elastic waves caused by corona discharges in an oil-immersed pole transformer

Sakoda T., Nieda H., Ando K.

IEEE Transactions on Dielectrics and Electrical Insulation 8 ( 2 ) 276 - 283 2001年4月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEE Transactions on Dielectrics and Electrical Insulation

Measurements of elastic waves brought by a pulse of simulated corona discharge in an oil immersed pole transformer and a model tank filled with oil were performed in order to identify the location of insulation deterioration, using an acoustic emission (AE) technique. The detected AE signals were analyzed by means of a fast Fourier transform (FFT), and properties of elastic waves influenced by the existence of insulated windings and magnetic core for power transformation in the transformer were investigated. As the result, almost all the initial AE signals detected on the wall of the transformer tank were Lamb waves caused by the oscillation waves passing through the insulating paper and oil with repeating transmission, reflection and refraction. Also, it was possible to recognize whether the measured elastic wave was influenced by windings and their insulating papers or not, by the FFT analysis. This suggests that the location accuracy of the corona discharge in the transformers would be improved.

DOI： 10.1109/94.919956

Electric field calculation in composite dielectrics by first-order triangular surface charge method

Sakoda T., Nieda H., Ando K.

Electrical Engineering in Japan (English translation of Denki Gakkai Ronbunshi) 135 ( 1 ) 8 - 14 2001年4月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Electrical Engineering in Japan (English translation of Denki Gakkai Ronbunshi)

This paper proposes a technique for calculating electric fields in composite dielectrics by the first-order triangular surface charge method. The proposed technique utilizes two kinds of triangular elements, namely, conforming and nonconforming elements: these are elements whose charge density is continuous and discontinuous between the neighboring elements, respectively. We basically apply nonconforming elements at the edges of a polyhedral shape where the normal component of electric field cannot be fixed. We have computed the electric field for a spherical or a rectangular solid dielectric in the presence of a uniform field. Comparison shows that the proposed first-order method works better than the zeroth-order one, and that, in particular, the combined use of conforming and nonconforming elements produces the highest accuracy. © 2001 Scripta Technica.

DOI： 10.1002/1520-6416(20010415)135:1<8::AID-EEJ2>3.0.CO;2-Y

直列ギャップ付避雷器の漏れ電流へのスペーサ表面の金属汚損の影響

深野孝人, 堀口友隆, 大坪昌久, 成烈文, 迫田達也, 贄田寛

電気設備学会誌 20 ( 10 ) 828 - 834 2000年10月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：電気設備学会

Studies on the optimum condition for the formation of a neutral loop discharge plasma

Sung Y., Uchino K., Muraoka K., Sakoda T.

Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films 18 ( 5 ) 2149 - 2152 2000年9月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films

Electron behavior was studied to obtain the guidelines for the design and operation of a new plasma source by a magnetic neutral loop discharge (NLD) plasma devices. Model incorporating the effects of a three-dimensional electromagnetic field with spatial decay of the radio frequency electric field, and the limitation of the spatial extent of the electron motion was used to analyze the electron behavior. Optimum plasma production value existed for the optimum magnetic field gradient.

DOI： 10.1116/1.1286391

Analysis of acoustic emissions caused by the partial discharge in the insulation oil

Sakoda T., Arita T., Nieda H., Ando K.

IEEE International Conference on Conduction and Breakdown in Dielectric Liquids, ICDL 483 - 486 1999年12月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEE International Conference on Conduction and Breakdown in Dielectric Liquids, ICDL

In order to diagnose the deterioration of insulation and evaluate its location in oil-filled pole transformer, measurements of elastic waves brought by corona discharges in oil were performed based on an acoustic emission (AE) technique. The detected signals in these measurements were analyzed by means of a fast Fourier transform (FFT) and their properties were discussed theoretically. It was found that the AE signals due to the Lamb waves of symmetrical mode caused in a thin steel tank could be easily recognized by the FFT analyses of initial stages of the detected AE signals. This suggests that the accuracy on location of the AE sources in the transformer would be improved. Also, it was shown that a low pass filter was effective to improve the accuracy of location.

Acoustic emissions caused by the corona discharge in an oil-tank

Sakoda T., Arita T., Nieda H., Otsubo M., Honda C., Ando K.

IEE Conference Publication 5 ( 467 ) 1999年12月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：IEE Conference Publication

Measurements of sonic and ultrasonic waves brought by corona discharges were performed based on an acoustic emission (AE) technique, to diagnose the deterioration of insulation and its location in an oil - filled pole transformer. The detected signals in these measurements were analyzed by means of a fast Fourier transform (FFT) and their properties were discussed. It was found that the AE signals due to the Lamb waves caused in a thin steel tank can be easily recognized by the FFT analyses of initial stages of the detected AE signals. This indicates that the accuracy on location of the AE sources in the transformer can be improved. Also, it was shown that a low pass filter was effective to improve the accuracy of location.

Studies of elastic waves caused by corona discharges in oil

Sakoda T., Arita T., Nieda H., Ando K., Otsub M., Honda C.

IEEE Transactions on Dielectrics and Electrical Insulation 6 ( 6 ) 825 - 830 1999年12月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEE Transactions on Dielectrics and Electrical Insulation

In order to diagnose the deterioration of insulation and evaluate its location in oil-filled pole transformers, measurements of elastic waves brought by corona discharges in oil were performed, based on an acoustic emission (AE) technique. The detected signals in these measurements were analyzed by means of a fast Fourier transform (FFT) and their properties were discussed theoretically. It was found that the AE signals due to the Lamb waves of symmetric mode caused in a thin steel tank could be recognized easily by the FFT analysis of initial stages of the detected AE signals. This suggests that the accuracy on location of the AE sources in the transformer would be improved. Also, it was shown that a low pass filter was effective in improving the location accuracy.

DOI： 10.1109/94.822022

Studies of a magnetic neutral loop discharge based on laser diagnostics of electron behavior and atomic processes

Sakoda T., Miyao T., Uchino K., Muraoka K.

Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers 36 ( 11 ) 6981 - 6985 1997年11月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers

In order to understand plasma formation processes in a neutral loop discharge, measurements of population densities of excited levels of helium atoms were performed using laser induced fluorescence (LIF) spectroscopy. At the same time, profiles of electron density n e and electron temperature T e were measured using Thomson scattering. The results of these measurements were analyzed using a collisional-radiative model of helium atoms in the plasma. It was found that population densities of excited levels of the helium atoms were consistent with the values of n e and T e . This indicates that it is not necessary to consider an existence of a high energy electron component which may be supposed to theoretically exist in addition to the Maxwellian energy distribution function for the bulk of electrons at the measured temperature T e . Also, it was shown that the energy deposition to electrons in the vicinity of the neutral loop plays a essential role in the formation of the neutral loop discharge plasma.

Electron temperature and density profiles in a neutral loop discharge plasma

Sakoda T., Iwamiya H., Uchino K., Muraoka K., Itoh M., Uchida T.

Japanese Journal of Applied Physics, Part 2: Letters 36 ( 1 PART A/B ) 1997年1月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Japanese Journal of Applied Physics, Part 2: Letters

Thomson scattering measurements of electron temperature and density in a neutral loop discharge (NLD) plasma were performed in order to reveal electron behavior around the neutral loop. The method yielded unambiguous and reliable results, enabling quantitative analyses of particle balance to be made. The results showed that the electron temperature had a peak on the neutral loop and, in contrast, the electron density had a peak at a position radially inward from the neutral loop. We suggest that charged particles are produced by electron impact ionization of argon atoms on the neutral loop and then flow radially inward. The effect of the magnetic field strength on the NLD plasma formation is also discussed.