Simulation and verification of emergency diesel generator relay protection scheme in nuclear power plant based on loading inrush current

Abstract The relay protection of the emergency diesel generator system is significantly affected by the inrush current from the auxiliary motor loading. Therefore, the rationality of its setting and coordination is crucial. Based on actual data from a certain plant, this paper constructs a protection configuration model for the nuclear power plant’s emergency diesel generator. It conducts relevant simulation calculations to demonstrate the rationality and feasibility of the emergency diesel generator protection setting scheme. By integrating the relationship between the tripping zone and braking zone based on the physical characteristics and action periods of the emergency diesel generator, setting values are determined. Transient simulation tests are conducted in conjunction with the TCC curve and action sequence, and the results verify the rationality of the design work presented in this paper.