发电机中性点接地变压器短路电阻和短路电抗测算方法

Calculation Method for Generator Neutral Earthing Transformer Short Circuit Resistance and Reactance

本文提出了一种发电机中性点接地变压器短路电阻和短路电抗测算方法,通过模拟定子单相接地故障,由保护装置记录故障时的机端和中性点零序电压,利用发电机定子单相接地故障时机端零序电压和中性点零序电压工频分量近似相等的特征,采用傅立叶算法求得短路电阻和短路电抗。现场定子接地故障录波数据验证了该方法的正确性。

This paper presents a new method to calculate the short circuit resistance and reactance of generator neutral earthing transformer. Theoretical basis is that term zero sequence voltage equal to neutral zero sequence voltage during stator earth fault. Short circuit resistance and reactance of generator neutral earthing transformer can be calculated by full-wave Fourier algorithm. Actual stator earth fault record data indicate that the method is correct.