Simulation calculation and real-type experiment verification of single-phase ground fault in power system of 6.6kV nuclear power plan

The high-voltage plant power system of nuclear power plants contains various cables. When a single-phase ground fault occurs in the system, the input of a large number of cables will increase the capacitive current of the system. At the same time, in the environment of strong radiation and high temperature, the cable insulation is very easy to age. At present, the research on single-phase fault of 6.6kV system mainly focuses on simulation calculation, and lacks the verification of real-type experiment due to the cost and difficulty. Aiming at the problems faced by a domestic nuclear power plant, this paper established a 6.6kV high-voltage utility power ground fault simulation model based on the high-voltage utility cable wiring topology, and studied the fault characteristics of the system under different single-phase faults. A 6.6kV system real-type experiment platform was built to simulate metal grounding and cable insulation faults when the neutral point was not grounded and the extinction coil was grounded, and the agreement between the test and the simulation calculation results is high, but there is a difference in the arcing ground triggered by the cable insulation faults, so as to provide a reference for the maintenance and safe operation of the cable of the power system of the plant of the nuclear power plant.