一起罕见的电容式电流互感器缺陷的发现和分析

介绍和诊断了一起罕见的因电容式电流互感器末屏没有处于等电位体的缺陷导致油色谱测试结果中乙炔含量超标的故障。不能通过状态检修例行试验中的介损测试结果有效地发现和诊断此类故障;在油色谱跟踪试验中,在氢气和总烃含量还没有明显增长即远没有超标的情况下,就出现很大的乙炔含量,这与一般绝缘故障的发展规律相违背。解体发现,故障原因是对缠绕末屏的铜编织带的设计缺陷使得末屏没有处于整体的等电位体。如果在色谱测试结果中氢气和甲烷含量尚无明显增长的情况下就直接出现乙炔含量,这说明电容式电流互感器有可能出现了此类故障。

The Discoverv and Analvsis of a Rare Defect of Capacitive Current Transformer

In this paper,a rare non equipotential fault of end shield of capacitive current transformer causing overproof acetylene in the oil chromatography test results is introduced and diagnosed.This fault can’t be effectively found through dielectric loss factor test in the condition maintenance and routine test.In the oil chromatography test,the overproof acetylene directly occurs in great deal when hydrogen and total hydrocarbon haven’t grown apparently(namely,in case of not exceeding standard),which violates the law of development of general insulation fault.When disassembled,it is found that the cause of the failure is on winding screens in the copper braid with design flaws making the end shiled is not in equipotential body.If in the color spectrum test results,the content of hydrogen and methane did not yet have significantly increased,it appears directly acetylene content,this indicating the capacitive current transformers may have occurred such failure.