位置分解能を持つケーブルの水トリー劣化標定を目指した電荷挙動の測定

カテゴリ: 研究会(論文単位)

論文No: DEI10006

グループ名: 【A】基礎・材料・共通部門 誘電・絶縁材料研究会

発行日: 2010/01/18

タイトル(英語): Analysis of Charge Behavior Aiming for Localization of Water Tree Degradation in XLPE Cables

著者名: 樋江井 進(愛知工業大学),穂積 直裕(愛知工業大学),栗原 隆史(電力中央研究所),岡本 達希(電力中央研究所),辻 泰三(中部電力)

著者名(英語): Susumu Hiei(Aich Institute of Technology),Naohiro Hozumi(Aich Institute of Technology),Takashi Kurihara(Central Research Institute of Electric Power Industry),Tatsuki Okamoto(Central Research Institute of Electric Power Industry),Taizo Tsuji(Chubu Electric Power Co.,Inc.)

キーワード: 水トリー|ポリマーケーブル|診断|パルス|残留電荷|water tree|polymeric cable|diagnosis|pulse|residual charge

要約(日本語): 水トリー劣化診断法として著者らはパルス電圧を用いた残留電荷法を提案してきた。本研究では，本手法により位置標定が可能であることを確認するため，水トリー劣化した通信ケーブルを使用した基礎検討を行った。具体的には，健全ケーブル400メートルの中間点に水トリー劣化ケーブル5メートルを接続し，直流課電後，パルス電圧を課電し，残留電荷の応答を確認した。その結果，電圧課電端で水トリー劣化ケーブルから伝播してきたと推定される残留電荷信号を確認することができ，水トリー劣化が進んだケーブルであれば，本手法により位置標定が可能であるとの見通しを得た。

要約(英語): Water tree is a degradation mode of power cable with polymeric insulation. A water tree is composed of small droplets filled with water. As the conductivity in water tree is very high, it leads to dielectric breakdown when it grows up. As inside the water tree is filled with trap sites, it is polarized with a certain distribution of relaxation time when a DC poling voltage is applied. Although its depolarization process after removing the poling voltage is determined by ambient temperature, applying a "depolarizing voltage" with the opposite polarity can accelerate the process. If a short pulse propagating through the cable is employed as a depolarization voltage, we may locate the water tree by looking at the time-resolved pulse response. This would lead to a diagnosing method with spatial resolution. In order to retain 100 m of spatial resolution, the response should be as sharp as 1 μs. As a preliminary study, a coaxial communication cable with 5 m in length was aged to form water trees, and inserted in the middle of a 400-m-long non-aged cable. A DC poling voltage was applied followed by a pulse voltage with opposite polarity. The rising time of the pulse was several hundreds of nanoseconds. An echoic response with about 1 μs in width was observed, suggesting that a rapid depolarization took place. No such response was seen when the cable specimen was not aged. Although the charge intensity was lower compared to the response to conventional AC depolarizing voltage, we concluded that the technique is quite feasible.

原稿種別: 日本語

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