Application of the percentage differential relay and stator earth fault protection in synchronous generators

Abstract Synchronous generators play a vital role in the power system. The relay protection distributed in the system can quickly remove the fault, effectively respond to it, and solve the problem. In this paper, the characteristics of a synchronous generator neutral ungrounded are analyzed when various unsymmetrical and symmetrical faults occur in the internal and external areas, and the percentage differential relay is used to solve the problem of short circuit faults. For the single line-to-ground fault, the stator earth fault protection is also introduced to compensate for the shortcomings of the generator neutral ungrounded. The simulation software MATLAB/Simulink is applied for modeling and analysis, and the strategy of composite protection solves the problem of unsymmetrical failure for the neutral point ungrounding generator.