Research Of Transient Simulation And Protection For Synchronous Generator Stator Ground Fault

The ground faults in the generator stator are by far common faults to whichgenerators are subjected. Internal short-circuit faults, which may immediately damagegenerator, are always preceded by the ground faults. With the development of powersystem, the capacity of single generator is growing, and this demands higherperformance for large generator protective relay. Based on above, firstly the paperpresents some research achievement on stator ground fault transient simulation of statorwindings in large generators. The transient simulation program is proved by theconstraction with the simulate experimentation date of an analog synchronous generator,which shows the same trend as the existing laws. To resolve the situation that the exitingprotcetion of third-harmonic, an atresia scheme of the protection based on the faultcomponent of the phase of third-harmonic voltage and a kind of protection scheme based onthe fault component of zero-sequence voltage and the phase of third-harmonic voltage at theterminalsandneutralaredeveloped,andtheycanobtainhighersensitivityandreliability andprovide 100% protection for the stator windings.