Study Of Adaptive Judgement Of Generator Protection For Stator Winding Single-ground Fault

Stator winding single-ground fault, one of the common electrical faults, is caused by the destruction of insulation. It may destroy the iron core or expand to phase–to-phase fault and winding fault in the same phase, which is very disastrous to the generator. Therefore, it's urgent and practical to find an adaptive judgement of stator winding single-ground fault protection, which can detect the fault and then open the breaker or send a signal at once.This paper puts forward the adaptive judgement of stator winding single-ground fault protection, based on fault transient component of basic zero-sequence voltage and harmonic voltage. The judgement can adjust the restrain quotiety adaptive through the relation of spectrum energy of generator's terminal and neutral voltage of the transient component of basic zero-sequence voltage and third harmonic voltage. The restrain quotiety can adjust to the working condition adaptive, which can get a higher sensitivity effectively.Because there is no such software of stator winding single-ground fault by now, the author puts up with a new simulation software on the basis of the model of multi-loop and capacitance pre-distribution, in order to checkout the action effect of the adaptive judgement. This paper simulates the condition of stator winding single-ground fault by using this software. The result shows that the characteristics of the adaptive judgement are high sensitivity, high reliability and high antinoise capability.