330 kV倒置式電流互感器噴油事故分析及預防措施
劉威峰,閆振華,周秀,馬云龍,李奇超,徐玉華
(國網寧夏電力有限公司電力科學研究院,寧夏 銀川 750011)
摘 要:針對一起倒置式電流互感器的噴油事故,分析了互感器的結構及絕緣特點,綜合三比值法、特征氣體組分、大衛三角形法對試驗數據進行判斷,并結合解體檢查認為造成此類故障的原因:一是主絕緣制造工藝不良,絕緣包裹過程包扎不均勻,極易引起局部電場不均勻、局部發熱;二是安裝工藝不良引起密封不嚴所致,極易引起絕緣內部受潮。上述缺陷會引起絕緣油劣化分解產生大量氣體,嚴重者導致頭部金屬膨脹器冒頂、噴油甚至爆炸事故,給出了相關處理措施,避免此類故障再次發生。
關鍵詞:倒置式電流互感器;膨脹器;油中溶解氣體;絕緣油
中圖分類號:TM452 文獻標識碼:B 文章編號:1007-3175(2020)02-0058-04
Analysis and Preventive Measures of 330 kV Inverted Current Transformer Oil Injection Accident
LIU Wei-feng, YAN Zhen-hua, ZHOU Xiu, MA Yun-long, LI Qi-chao, XU Yu-hua
(State Grid Ningxia Electric Power Company Electric Power Research Institute, Yinchuan 750011 , China)
Abstract: Aiming at an oil injection accident of inverted current transformer, this paper analyzed the structure and insulation characteristics, synthesized three-ratio method, characteristic gas component method and David triangle method to carry out judgments for testing data, and combined strip inspection to conclude this type of faults causes: on the one hand, major insulation manufacturing technique badness and insulation-wrapping process bind-up asymmetry are easy to cause the partial electric field asymmetry and local heating, on the other hand, the installation technology badness causes untight seal, easy to cause insulation interior damp. The above mentioned defects will cause the insulation oil degradation decompose to generate a large amount of gas, which may cause the head metal expander collapse, the oil injection or even the explosion accident. This paper gave the relevant treatment measure to avoid this type of faults happening again.
Key words: inverted current transformer; expander; dissolved gas in oil; insulating oil
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