External power supply type grounding protection system and method

The invention discloses an external power supply type grounding protection system and method, which are used for a nuclear power supply system. The system comprises a power supply unit used for outputting a test power supply, an adjusting unit used for adjusting a resistive current of a nuclear power supply system according to a capacitive current of the nuclear power supply system, and a resistance increasing unit used for reducing a shunt current shunted to the power supply unit in a test process. The acquisition unit is used for acquiring feedback data; the processing unit is used for generating a grounding protection signal according to the feedback data; by implementing the invention, the resistive current of the nuclear power supply system can be adjusted, the shunt current shunted to the power supply unit is reduced, the adverse effect of lowering the grounding resistance of the nuclear power supply system is reduced, the calculation accuracy of the grounding protection signal is improved, and the prot