小电流接地系统的接地故障处置方法

Ground Fault Handling Method for Small Current Grounding System

小电流接地系统发生单相接地引发电力系统设备损坏、人畜触电情况已屡见不鲜。从安全角度考虑,已经对电力系统内老旧变电站配网进行了技改,当配网发生单相接地时,零序保护动作跳闸切除接地故障。由于需要改造变电站存量大,在一段时间内,配网接地后发信号与跳闸两种情况会同时存在。文章主要针对小电流接地系统发生单相接地后仅发信号的情况进行分析、总结,制定相应处理方法供运行人员参考。

Single phase grounding in small current grounding system causes power system equipment damage and electric shock to human and livestock.From a safety perspective,the old substation distribution network in the power system has been technically modified.When a single-phase grounding occurs in the distribution network,the zero-sequence protection action trips to remove the ground fault.Due to the large stock of substations that need to be retrofitted,within a period of time,both the signal and the trip after the distribution network is grounded will exist simultaneously.In this paper,the situation of single-phase grounding in small current grounding system was analyzed and summarized,and the corresponding processing methods for reference of operators were formulated.