10kV小电阻接地系统特殊问题的研究

Study on Special Problems of 10 kV Systems with Low Resistance Grounding

提出了 1 0 k V小电阻接地系统的系统模型和节点电压方程 ,分析了该系统电缆线路对地电容参数不对称所引起的流过接地变压器中性点的零序电流的变化规律、高压侧出现单相接地故障对低压侧的影响及变电所接地网接地不良所产生的接地变压器中性点零序电压升高 。

This paper uses node method to illustate that asymmetric line capacitance parameter will generate zero sequence current which flows the neutral point of earthing transformer in 10 kV low resistance grounded system, and shows that if grounding network of substation is imperfect, the zero sequence voltage will increase, finally, gives the conclusion through simulation that zero sequence current protection may misoperate.