分接开关受潮导致变压器绝缘电阻降低的分析

针对三绕组有载调压开关变压器绝缘电阻不合格问题展开检查,分析了变压器高压侧接线及绝缘电阻测试原理,综合分析各项试验,初步判断绝缘下降原因在分接开关。通过分接开关试验,发现有载分接开关进水受潮,造成绝缘电阻降低,经过处理绝缘电阻恢复合格。

Analysis on the insulation resistance reduction oftransformer due to tap switch moisture

For the unqualified transformer insulation resistance of the three winding on-load tapchanger, the high voltage side connection and the testing principle of transformer insulationresistance are analyzed. Through comprehensivly analyzing each test, the cause of the insulationreduction is preliminarily concluded to be tap changing switch. By the test of tap changingswitch, it is found that on-load tap changer dampened by the inlet water, and lead to the insulation resistance reduction. So through thetreatment method the insulation resistanceis qualified.