适用于矿山电网的单相接地故障选线新方法

A novel line selection method of single phase grounding fault suitable for coal mine power network

针对现有矿山电网故障选线方法信号检测灵敏度低、受中性点运行方式及接地点电弧的影响大等问题,分析了单相接地故障的序电流及谐波电流特性,根据基波负序电流主要经接地线路首端流向系统、非接地线路首端无基波负序电流流过等结论,提出了一种以基波负序电流为主判据、谐波总电流为辅助判据的单相接地故障选线新方法,并对该方法进行了可靠性分析及仿真计算。仿真结果表明,与传统故障选线方法相比,该方法受中性点运行方式、故障类型等因素的影响小,具有更好的可靠性和自适应性。

For problems that existing fault line selection methods for coal mine power network had low detecting sensitivity and were easily influenced by neutral point operation mode and electric arc at grounding point,characteristics of sequence current and harmonic current of single phase grounding fault were analyzed,and conclusions were gotten including that the fundamental negative sequence current was allotted to distribution system from grounding line head,and no fundamental negative sequence current flowed through health line head.According above conclusions,a novel line selection method of single phase grounding fault was proposed which took fundamental negative sequence current as the first criteria and harmonic current as the second criteria,and reliability analysis and simulation calculation about the method were taken out.The simulation results show that there is little influence on the method by neutral point operation mode and fault type,and the method has better reliability and adaptability compared with traditional methods.