配电网离线故障定位方法研究与实现

Research and Implementation of Off-line Fault Location for Distribution Network

分析了配电网单相接地故障定位中接地过渡电阻和线路分布电容对注入信号的影响,由此确定了线路的定位模型,并进一步分析了接地过渡电阻、线路分布电容与定位可靠性之间的函数关系,得出以下结论:定位可靠性随过渡电阻的增大而降低,随注入信号频率的增大而降低,随线路结构的复杂而降低。进一步提出交直流综合的定位方法以及电阻—长度积的定义,用电阻—长度积作为选用交流或直流方法的依据,并通过现场试验对交直流综合方法的有效性进行了验证。

This paper discusses the influence of grounded fault resistor and line＇s distributed capacitance on the injected signal for location of single phase grounded fault in a distribution network. It develops a model of line for location as well. Based on the discussions, functions of location reliability with grounded fault resistor and line＇ s distributed capacitance are derived. Based on the functions, following conclusions are obtained： the reliability drops with increasing of resistor value, injected signal＇s frequency and complexity of line＇s structure. A location method of combining DC method with AC method is presented. The definition on product of grounded fault resistor value with line length is made as a basis of choosing DC method or AC method for location. The location method proposed is validated by field experiments.