大型水轮发电机中性点接地装置对中性点位移电压的影响

The Influence on Neutral Displacement Voltage of Neutral Grounding Equipment in Giant Hydro Generator

大型水轮发电机接地电容电流较大,为限制接地点故障电流,一般在中性点接地装置中引入感性电流以抵消部分容性电流。近年来,部分大型水轮发电机发生了明显的中性点位移现象,且在接入中性点接地装置后有放大趋势。本文对中性点接地装置补偿电流及参数设定、中性点位移电压的成因以及中性点接地装置对其影响进行分析并给出建议。

The grounding capacity current of giant hydrogenerator is large,generally,in order to restrict fault current,the inductive current is introduced by the neutral grounding device to offset some capacity current.During past years,the phenomenon of neutral displacement has occurred in some giant hydrogenerator,and there is a enlarge trend after connecting the neutral grounding device.In this paper,the compensating current and parameters setting of neutral grounding device,the causes of neutral displacement voltage and the influence of neutral grounding device are analyzed,and the suggestions are given in the end.