橋絡水トリーが発生した乾式架橋・三層同時押出方式6.6 kV CVケーブルの水トリー劣化診断に関する基礎検討

カテゴリ: 論文誌(論文単位)

グループ名: 【A】基礎・材料・共通部門

発行日: 2019/04/01

タイトル(英語): Fundamental Study on Water-tree Degradation Diagnosis for Dry-cured and Extruded Three-layer (E-E Type) 6.6 kV XLPE Cables with Penetrated Water Tree

著者名: 栗原　隆史（（一財）電力中央研究所），佐藤　智之（東北電力（株）），樺澤　祐一郎（東北電力（株）），長嶋　友宏（東北電力（株））

著者名(英語): Takashi Kurihara (Central Research Institute of Electric Power Industry), Tomoyuki Sato (Tohoku Electric Power Co., Inc.), Yuichiro Kabasawa (Tohoku Electric Power Co., Inc.), Tomohiro Nagashima (Tohoku Electric Power Co., Inc.)

キーワード: 高圧CVケーブル，三層同時押出，橋絡水トリー，加速劣化，劣化診断　　high-voltage XLPE cables，E-E type，penetrated water tree，accelerated water-treeing test，degradation diagnosis

要約(英語): Harmful water trees, such as penetrated water trees bridging insulation, have not been found in removed dry-cured and extruded three-layer (E-E type) 6.6 kV cross-linked polyethylene (XLPE) cables since they were introduced into electric power systems more than 30 years ago. However, water-tree degradation becomes a serious problem as the operating duration increases, making it essential to diagnose water-tree degradation. Therefore, to establish the degradation index of water-tree degradation for these cables, growth of water trees should be accelerated for removed XLPE cables. In this study, an accelerated water-treeing test was performed for dry-cured and E-E type 6.6 kV XLPE cables removed after approximately 20 years of operation. As a result, we successfully found a penetrated water tree in one of the XLPE cables. Additionally, for the cable with a penetrated water tree, the values for electrical insulation characteristics, such as a DC leakage current, an AC superposition current, and dielectric loss tangent, were investigated. As a result, its DC leakage and AC superposition currents were above the threshold values indicating the existence of at least one penetrated water tree for E-T type 6.6 kV XLPE cables, whose type is older than E-E type. This result suggests that DC leakage and AC superposition currents are useful in finding penetrated water trees in water-tree degradation diagnosis for dry-cured and E-E type 6.6 kV XLPE cables.

本誌: 電気学会論文誌A（基礎・材料・共通部門誌） Vol.139 No.4 （2019） 特集：平成30年基礎・材料・共通部門大会

本誌掲載ページ: 226-233 p

原稿種別: 論文／日本語

電子版へのリンク: https://www.jstage.jst.go.jp/article/ieejfms/139/4/139_226/_article/-char/ja/