500kV香山变电站变压器中性点小电抗过电压研究

Study on Overvoltage of 500kV Xiangshan Substation Transformer with Neutral Point Grounded through Small Reactance

为限制单相接地短路电流,香山变主变中性点装设15Ω小电抗。通过对小电抗上的工频过电压及操作过电压进行计算分析,得出中性点小电抗的绝缘水平是足够的结论,并选择了中性点小电抗避雷器,确保该小电抗安全运行。

In order to limit the single-phase ground short circuit current,small reactor earthing device 15Ω is installed at the neutral point of Xiangshan substation main transformer.Through calculation and analysis of power frequency overvoltage and operating overvoltage on the small reactor,the conclusion is drawn that the insulation level of the small reactor connected to the neutral point is enough high,and lightning arrester shunted with small reactor connected to neutral point is chosen to ensure the safe operation of the small reactor.