Generator Excitation Circuit And Ground Fault Protection Programs

So far ,there has existed several kinds of theory of ground fault protection for field winding of generator . In these methods, pingpong bridge field ground protection is a simple and effective one.This paper is based on the pingpong bridge field ground protection ,itpresents one point to ground protection scheme which include the self-checking method of switches. The two point to ground protection scheme presents self-adapting fault location warp criterion after evaluating the effect on the calculation of fault location made by the change of transient resistance in the process of bridge switch. In order to make up the shortcoming of location warp criterion, this paper presents a comprehensive scheme into which integrate the second harmonic criterion.