单相接地故障综合判据选线研究

通过对影响现有选线准确性因素的分析,认为单相接地选线原理的单一性和选线保护裕度低是影响接地选线准确性的主要原因,提出了基于电弧接地故障的暂态电流互积求和选线法和针对稳态接地故障的导纳互差求和选线法和融合电流选线法的综合选线方法.大量的6 kV电网模拟试验和实际电网运行情况表明,该方法有效地提高了选线的准确性.

Study on Single-Phase-To-Ground Fault Protection Using Synthetic Criterion

To present the main reason that effects fault line detection accuracy for indirect grounding power system is simplex selecting fault line method and low protective margin by analysing existing selecting fault line method. This paper presents synthetic detecting fault feeder method based on the method of summation of mutual integral of transient current for intermittent arc earth fault and the method of summation of admittance mutual difference and fused current method for steady earth fault. Lots of experiment and operation results shows that this method increases the accuracy of detecting fault line.