双频法在浮地交流电网绝缘故障定位中的应用

Research on application of double frequency principle to insulation fault locating in earth free AC system

针对浮地交流电网,提出了用双频法对电网绝缘故障支路定位的方案,分析了对浮地电网注入低频信号后的漏电流特性,给出了从包含复杂频率成分的信号中提取注入频率电量的方法。注入频率的选择直接影响到双频法应用于电网绝缘故障支路定位的效果,在给定注入信号频率的选定原则基础上,根据实际情况,确定了注入信号频率的可选择范围。通过现场实际应用表明,该方案是可行的。

Double frequency principle is adopted in detecting the fault branch of earth free AC system.Characteristic s of leaking current are analyzed after low frequency signal is injected into earth free AC system.The method is given for picking up the injecting frequency electricity from the sig-nal with complicated frequency components.The selection of injecting frequency directly influences the result of fault branch locating.Based on the given principle for injecting frequency selection,the selectable frequency range is determined according to the real condition.The site application shows that this method is feasible.