大型变压器低压侧绕组直流电阻不平衡率超标原因分析

Reason Analysis of DC Resistance Imbalance Rate Over Standard of Low Voltage Side Winding of Large Transformer

在开展某大型水电厂主变压器电气预防性试验时,发现B相变压器低压侧绕组直流电阻不平衡率超标,经不同的试验方法检测及对比历年试验数据分析原因,在此基础上,结合笔者的工作经验,给出该类异常情况的原因排查方法和防范措施。

During the electrical preventive test of the main transformer of a large hydropower plant,it is found that the unbalance rate of DC resistance of the low-voltage side winding of phase B transformer exceeds standard.The cause of test data analysis is tested by different test methods and compared with that of previous years.In this paper,the cause investigation methods and preventive measures for this kind of abnormal situation are given.