一起有载调压开关故障导致220kV变压器停运事件分析

Analysis of a 220 kV Transformer Outage Caused by the OLTC Fault

对一起有载调压开关故障导致220kV变压器停运的事件进行分析。通过外观检查、保护及二次回路检查、电气试验及油样分析和解体检查,确定该起故障的直接原因为有载调压开关在切换过程中发生极间和相间短路,而根本原因为有载调压开关的零部件及其在生产安装过程中存在质量缺陷,不能有效防止切换过程中产生的电弧。为了防止类似故障再次发生,从生产、运行和维护等方面给出相关建议。

A 220 kV transformer outage caused by the OLTC(on-load tap-changer) fault is analyzed.Based on the appearance inspection,protection and secondary circuit inspection,electrical test,oil sample analysis and disassembly inspection,it is determined that the direct cause of the fault is the interelectrode short circuit and the interphase short circuit during the switching process of the OLTC.The underlying cause is quality defects of OLTC’ s parts in the process of production and installation which can not effectively prevent the arc generated in the switching process.In order to prevent similar faults from happening again,suggestions are proposed from aspects of production,operation and maintenance and so on.