直流输电导致变压器噪声异常的测试及分析

Testing and Analysis of Transformer Abnormal Noise Caused by DC Transmission

摘要:

变压器噪声增大可能由于变压器内部故障，或非正常运行工况引起。针对220 kV 某变电站主变压器噪声异 常的情况，通过分析运行工况，对噪声振动、中性点直流量进行测试及分析，以及将主变压器噪声异常时的时间与德 阳换流站切换单极大地回路运行的时间进行对比，发现该主变压器噪声异常的原因是德阳换流站直流接地极电流导 致其发生直流偏磁，直流接地极电流导致单相三柱式变压器噪声异常的距离可达到300 km。介绍了特高压直流接地 极电流对四川电网变压器的影响情况，并提出了变压器直流偏磁的防护建议。

Abstract:

The increase of transformer noise can be caused by its internal fault or abnormal operating conditions． Based on a main transformer in a 220 kV substation，the reason of its abnormal noise is found out． Through analyzing the operating conditions， testing noise and vibration，measuring DC of the neutral point and comparing the time of abnormal noise with the time of monopole ground return operation switched by Deyang converter station，the results show that the transformer abnormal noise is caused by its DC bias which is due to the current of DC grounding pole in Deyang converter station． And its affecting distances are up to 300 km． The protection measures for UHV DC bias current of transformers in Sichuan power grid are introduced．