Abstract When the single to ground fault occurs in neutral unearthed system, the fault point must be found as soon as possible to avoid a phase to phase short. This paper discusses the zero-sequence voltage, zero-sequence current of the system and the power losses and temperature change in fault point. The conclusion is: the zero-sequence voltage make the fault point give out heat which can be detected by Infrared Thermometer,field test performed proves that this method is practical and feasible .
2014, Vol. 15 
