The control rod drive mechanism (CRDM) is the core component that regulates the nuclear reaction rate. And it is one of the most important loads in the nuclear power plant. The CRDM power system uses two parallel generators to achieve reliable power supply. Stator single-phase ground fault is the most common fault type of the CRDM power system generator. When ground fault occurs, it is of great significance to accurately solve the fault location of the winding for rapid fault repair and timely restoration of power supply. In this paper, combined with the structural characteristics of the CRDM power system, the winding potential distribution characteristics under the Zig-Zag winding wiring form are geometrically modeled, and the winding fault location method is constructed. PSCAD/EMTDC simulation analysis verifies the accuracy of the proposed method. It shows that the proposed method is not affected by the location and transition resistance of the ground fault, and has strong engineering practicability.

CRDM power system,stator ground fault,fault locating,Zig-Zag wiring form