地铁杂散电流对浙江电网变压器运行影响及治理措施

Influence of Metro Stray Current on Transformer Operation in Zhejiang Power Grid and the Control Measures

地铁在解决城市交通问题中发挥着重要作用,但也带来了振动、噪声、电磁干扰和杂散电流等问题。地铁杂散电流会通过大地流入中性点接地的变压器,造成变压器出现直流偏磁现象,影响变压器的正常运行。首先结合浙江电网发生的一起地铁杂散电流导致220 kV变压器直流偏磁事件,分析了地铁杂散电流的产生原因及其对变压器运行的影响。随后,介绍了地铁杂散电流的治理措施及变压器直流偏磁的抑制方法。最后,提出了杂散电流引起变压器直流偏磁的防治思路。

Subway plays an important role in intra-city public transportation. Meanwhile, it usually accompanies problems including vibration, noise, electromagnetic interference and stray current, which flows into the neutral-grounded transformer through the earth and leads to DC bias, affecting the normal operation of the transformer. In line with DC bias of a 220 kV transformer in Zhejiang power grid caused by stray current of metro, this paper analyzes the causes of the stray current and its impact on transformer operation. Besides, it expounds control measures against the stray current and control method of DC bias of transformer. Finally,the paper puts forward some ideas for preventing DC bias of transformer resulting from stray current.