研究者詳細 - 小島　寛樹

講演・口頭発表等 - 小島　寛樹

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小島寛樹

第14回アドバンストSEMセミナー 2024年10月29日日立ハイテクアドバンストSEMテクノロジ特別共同研究事業

Partial Discharge Progress and Breakdown in Oil-Impregnated Paper Insulation System of Capacitor Voltage Transformers 国際会議

Y. Nagaki, K. Hayashi, H. Kojima, M. Yoshida, N. Hayakawa

10th International Conference on Condition Monitoring and Diagnosis 2024年10月24日 The Korean Institute of Electrical Engineers

開催年月日： 2024年10月

記述言語：英語会議種別：ポスター発表

開催地：Gangwon-do 国名：大韓民国

In this paper, towards the insulation diagnosis of capacitor voltage transformers (CVTs) based on partial discharge (PD) measurements, PD progress and breakdown (BD) characteristics in aluminum foil/oil-impregnated paper composite insulation system were discussed, especially in the transition from creeping PD to penetrating PD. PD extended in the creeping direction of oil-impregnated papers with bubbles, eroded and penetrated the 1st layer of oil-impregnated paper. The penetrating PD with large charge, long length and red light emission extended in H2-based gases. PD sequentially penetrated the laminated oil-impregnated papers and led to BD.

DOI： 10.23919/CMD62064.2024.10766131

Scopus

Partial Discharge Characteristics of Aluminum Foil/Oil-Impregnated Paper Composite Insulation System with Misaligned Aluminum Foils 招待有り国際会議

N. Hayakawa, K. Hayashi, Y. Nagaki, H. Kojima, M. Yoshida

10th International Conference on Condition Monitoring and Diagnosis 2024年10月22日 The Korean Institute of Electrical Engineers

開催年月日： 2024年10月

記述言語：英語会議種別：口頭発表（招待・特別）

開催地：Gangwon-do 国名：大韓民国

Capacitor voltage transformers (CVTs) composed of aluminum foil/oil-impregnated paper composite insulation system have been operated over 30 years in substations. The insulation diagnosis of CVTs are expected to be based on the measurement of partial discharge (PD) leading to breakdown (BD). The misalignment of aluminum foil electrodes in the fabrication and/or operation of CVTs may cause PD. This paper discussed the PD characteristics of misaligned aluminum foil electrodes toward the insulation diagnosis of CVTs. PD progressed in the creeping direction of oil-impregnated papers within the misalignment width of aluminum foil electrode peripheries. The creeping PD eroded the surface of the 1st layer of oil-impregnated paper and penetrated the other layers, leading to BD.

DOI： 10.23919/CMD62064.2024.10766108

Scopus

Concept of Condition Monitoring for Capacitor Voltage Transformers 国際会議

H. Isaji, M. Yoshida, Y. Nagaki, H. Kojima, N. Hayakawa

10th International Conference on Condition Monitoring and Diagnosis 2024年10月22日 The Korean Institute of Electrical Engineers

開催年月日： 2024年10月

記述言語：英語会議種別：ポスター発表

開催地：Gangwon-do 国名：大韓民国

It is important to establish methods for detecting internal abnormalities and diagnosing the accuracy of the transformation ratio of instrument transformers. In the case of a capacitor voltage transformer (CVT) with multiple oil-impregnated paper capacitors connected in series, partial discharge (PD) occurs due to the deterioration of capacitor elements. When PD is extended, the capacitor electrode is short-circuited and the transformation ratio changes. Namely, the diagnostic of transformation ratio is effective for detecting internal abnormalities of CVT. The change in the voltage division ratio was investigated by experimentally reproducing the phenomena from the generation of PD to a short circuit in the capacitor elements. On the other hand, the effect on the transformation ratio due to the difference in the position and number of short-circuited capacitor elements in the CVT was simulated. In a digital substation, secondary voltage values of several CVTs are obtained simultaneously using intelligent electronic devices (IED). Therefore, using programmable devices supported by the IEC 61850 communication protocol, data can be acquired from IEDs and CVT condition monitoring can be achieved with simple calculations.

DOI： 10.23919/CMD62064.2024.10766186

Scopus

回転機絶縁システム適用に向けたセルロースナノファイバー（CNF）成形板の電気絶縁特性

木村啓韻，小島寛樹，早川直樹，古田尚，奥村浩史，安食厚志，山中雄太，岩永拓実，岡本徹志

第55回電気電子絶縁材料システムシンポジウム 2024年9月27日電気学会基礎・材料・共通部門誘電・絶縁材料技術委員会