联合搜索零序电压变化量的小电阻接地配电网故障测距

Fault location of low resistance grounding distribution network based on joint search of zero sequence voltage variation

针对小电阻接地配电网单相故障后保护直接作用于跳闸,供电可靠性低的问题,提出一种基于零序电压变化量的故障测距方法。首先建立了考虑分布与集总参数相结合的配电线路故障分析模型,分析了零序电压沿线分布规律,推导了故障位置与故障区段首、末端零序电压、电流的关系,根据双端推算零序电压在故障点处差值最小原理来构建故障精确测距方程,采用进退-黄金分割法联合搜索求解故障距离。利用电磁暂态仿真软件搭建改进型IEEE34节点小电阻接地配电网故障仿真模型,同时在10 kV配电网真型故障试验平台进行验证。结果表明,所提方法测距精度高、定位速度快、鲁棒性强,具有良好的应用效果。

To solve the problem of low reliability of power supply due to the direct action of post fault protection on tripping in low resistance neutral grounded distribution network, a fault location method based on zero sequence voltage variation was proposed. Firstly, a distribution line fault analysis model considering the distribution and lumped parameters was established, the distribution of zero-sequence voltage along the line was analyzed, and relationship between the fault location and the zero-sequence voltage and current at the start and end of the fault section was deduced. The principle of the minimum difference of zero-sequence voltage was used at the fault point to construct the precise fault location equation. Advance and retreat-golden section joint search method was used to quickly determine the fault location. The model of improved IEEE34 node distribution network was created by power systems electromagnetic transient simulation software and various fault simulations were conducted. The fault location method was verified with a true fault test platform of 10 kV distribution network. The results demonstrate that the proposed method has the advantages of high positioning accuracy, quick positioning speed, good robustness, and a good application effect in actual comprehensive fault scenarios.