GISの絶縁状態診断および破壊予知技術
ライン

 

[研究背景]

 ガス絶縁開閉装置(GIS)は密閉した金属容器内に遮断器,断路器,避雷器,母線,変流器などを一括収納した構造となっており,SF6ガスや固体絶縁物を用いて絶縁されている.GISは従来の機器に比べ小型かつ高い信頼度を誇っているので,主要機器として世界の電力系統において使用されている.そのため,GISで事故が起きると莫大な被害が電力系統におよぶ.そこで,事故を未然に防ぐため,GISの絶縁状態診断および破壊予知の技術の確立を目指している.事故の要因は様々であるが,事故件数の半数以上を占める絶縁不良によるものを対象としている.絶縁不良の要因として,現在は異物について研究しており,今後は固体絶縁物内の欠陥についても予定している.

 固体絶縁物上に金属異物が付着した場合,絶縁物沿面上に帯電が形成され,その帯電の影響によってPD特性は複雑化する.どのようなPD信号が危険なレベルなのかを判断するためには,固体絶縁物の影響を考慮したPDメカニズムの解明が重要である.そこで,交流高電圧を突印するという独自の電圧印加方法を用いて,異物が固体絶縁物に付着する瞬間を模擬した実験をおこなっている.

 PD電流パルス波形には放電の発生・進展に関する物理情報が含まれているため,PD電流パルス波形から得られる各種パラメータを解析することにより,PDメカニズムについて検討を行うことができるものと考えられる.そこで,PD電流パルス波形を測定・解析するための手法であるPD電流パルス波形解析法(PD-CPWA)を開発し,交流高電圧印加時におけるPD電流パルス波形をnsecオーダーで取得し,電流値,立ち上がり峻度di/dt,立ち上がり時間tr,立ち下がり時間tf などの時間推移について解析している.測定はシールドルーム内で行っており,世界でもトップクラスである0.1pC級の高感度な測定が可能である.


[学術論文]
(7) H.Okubo, N.Hayakawa
"A Novel Technique for Partial Discharge and Breakdown Investigation Based on Current Pulse Waveform Analysis"
IEEE Trans. on Dielectrics and Electrical Insulation Vol.12, No.4, pp.736-744, 2005

(6) H.Okubo, N.Hayakawa, A.Matsushita
"The Relationship Between Partial Discharge Current Pulse Waveforms and Physical Mechanisms"
IEEE Electrical Insulation Magazine, Vol.18, No.3, pp.38-45, 2002

(5) 渋谷,早川,大久保
"N2/SF6混合ガス中におけるインパルス沿面放電進展メカニズム"
電学論B, Vol.121, No.4, pp.455-460, 2001

(4) 斎藤,高橋,早川,川北,大久保
"0.1Hz超低周波(VLF)交流高電圧印加時におけるGIS内金属異物挙動と絶縁破壊特性"
電学論B, Vol.121, No.3, pp.364-370, 2001

(3) N.Hayakawa, Y.Ishida, H.Nishiguchi, M.Hikita, H.Okubo
"Mechanism of Impulse Creepage Discharge Propagation on Charged Dielectrics Surface in SF6 Gas"
Trans. IEE of Japan, Vol.116-B, No.5, pp.600-606, 1996

(2) M.Hikita, Y.Ishida, N.Hayakawa, Y.Kito, H.Okubo
"Creepage Discharge Propagation on Charged Dielectric Surface in SF6 Gas and Its Optical Observation"
Trans. IEE of Japan, Vol.115-B, No.2, pp.180-186, 1995

(1) H.Okubo, M.Kanegami, M.Hikita
"Creepage Discharge Propagation in Air and SF6 Gas Influenced by Surface Charge on Solid Dielectrics"
IEEE Transaction on Dielectrics and Electrical Insulation, Vol.1, No.2, pp.294-304, 1994


[発表実績]

(19) N.Hayakawa, Y.Sugimori, H.Okubo
"Partial Discharge Current Pulse Waveform Analysis (PD-CPWA) Based on PD Mechanisms in Solid and Gas Media"
International Symposium on Electrical Insulating Materials, pp.812-815, 2005

(18) H.Okubo, S.Watanabe, N.Hayakawa and T.Kumai
"Insulation Degradation Mechanism of Epoxy Spacer Samples for GIS"
Gaseous Dielectrics X, pp.353-360, Greece, 2004.

(17) N.Hayakawa, S.Watanabe, T.Kumai, H.Okubo
"Partial Discharge Characteristics Leading to Breakdown of GIS Spacer Samples with Degraded Insulation Performance"
7th Intnl. Conf. on Properties and Applications of Dielectric Materials, Nagoya Japan, 2003

(16) H.Okubo, Y.Okamoto, N.Hayakawa, T.Hoshino, S.Matsumoto
"Partial Discharge Characteristics by Metallic Particle on Solid Insulator in GIS"
International Symposium on High Voltage Engineering, p.332, 2003

(15) S.Watanabe, N.Hayakawa, T.Kumai, H.Okubo
"Partial Discharge Characteristics of Long-Term Operated 550kV GCB Epoxy Spacer"
2002 Annual Report, Conference on Electrical Insulation and Dielectric Phenomena, pp.462-465, Mexico, 2002

(14) Y.Okamoto, N.Hayakawa, T.Hoshino, S.Matsumoto, H.Okubo
"Influence of Solid Insulator and Metallic Particles on Partial Discharge Characteristics in GIS"
14th Int. Conf. on Gas Discharges and thier Applications, pp.192-195, 2002

(13) H.Okubo, A.Matsushita, S.Watanabe, N.Hayakawa, T.Kumai
"Investigation of Electrical Insulation Diagnosis of Solid Insulators in GIS by Partial Discharge Current Pulse Waveform Analysis (PD-CPWA)"
2002 IEEE/PES T&D Yokohama, pp.925-930, Japan, 2002

(12) H.Okubo, A.Matsushita, N.Hayakawa
"Selective Partial Discharge Measurement Technique for HV Electric Power Equipment"
International Electrical Insulation Conference(INSUCON), pp.218-224, Germany, 2002

(11) A.Matsushita, K.Kato, N.Hayakawa, K,Kawakita, H.Okubo
"Partial Discharge Current Pulse Waveform Analysis (CPWA) for Electrical Insulation Diagnosis of Solid Insulators in GIS"
2001 Annual Report, Conference on Electrical Insulation and Dielectric Phenomena, pp.348-351, Canada, 2001

(10) N.Hayakawa, K.Kato, K.Kawakita, H.Okubo
"Metallic Particle Motion and Breakdown Characteristics in GIS with 0.1Hz Very Low Frequency (VLF) High Voltage Application
International Symposium on High Voltage Engineering, Vol.4, pp.445-448, 2001

(9) H.Okubo, D.Shibutani, N.Hayakawa
"Step Propagation Mechanism of Impulse Creepage Discharge in N2/SF6 Gas Mixtures"
Gaseous Dielectrics IX, pp.339-344, 2001

(8) A.Matsushita, D.Shibutani, K.Kato, N.Hayakawa, K,Kawakita, H.Okubo
"Time Transition of Partial Discharge Characteristics and Current Pulse Waveforms on Epoxy Surface in SF6 Gas"
International Symposium on High Voltage Engineering, pp.360-363, India, 2001

(7) H.Okubo, T.Takahashi, N.Hayakawa, H.Saitoh, K.Morita, T.Kikkawa
"Metallic Particle Behavior and Breakdown Characteristics in N2/SF6 Gas Mixture GIS"
13th Int. Conf. on Gas Discharges and thier Applications, pp.446-449, 2000

(6) N.Hayakawa, D.Shibutani, H.Okubo
"Impulse Creepage Discharge Propagation Characteristics on Solid Dielectrics in N2/SF6 Gas Mixtures"
13th Int. Conf. on Gas Discharges and thier Applications, pp.299-302, 2000

(5) H.Okubo, T.Yoshida, N.Hayakawa
"Propagation Characteristics of Impulse Creepage Discharge in N2/SF6 Gas Mixture"
,International Symposium on High Voltage Engineering, pp.188-191, 1999

(4) N.Hayakawa, T.Yoshida, H.Okubo
"Creepage Discharge Propagation Characteristics in N2/SF6 and air/SF6 Gas Mixtures"
Int. Workshop on High Volt. Eng., SP-99-19/HV-99-19, pp.97-102, 1999

(3) T.Yoshida, K.Kato, N.Hayakawa, H.Okubo
"Impulse Creepage Discharge Propagation Characteristics and Mechanisms in SF6 Gas and Gan Mixture"
Fourth Workshop & Conference on EHV Technology, pp1-5, 1998

(2) H.Okubo, Y.Ishida, H.Nishiguchi, N.Hayakawa, M.Hikita, Y.Kito
"Mechanism of Step-Wise Propagation of Positive Impulse Creepage Discharge in SF6 Gas under the Influence of Negative Surface charging on Dielectrics"
11th Int. Conf. on Gas Discharges and thier Applications, pp.288-291, 1995

(1) M.Hikita, Y.Ishida, N.Hayakawa, Y.Kito, H.Okubo
"Creepage Discharge Propagation on Charged Surface in SF6 Gas and its Optical Observation"
IEE of Japan Power & Energy, No.142, pp.239-244, 1994.

ライン