The frequent fuse of PT HV fuse at generator outlet under non-fault condition seriously threatens safe production of power plant. The PT HV fuse after the disassembly analysis and operation statistics analysis shows the characteristics of ‘slow fusing’. According to the actual field parameters in this paper

a calculation model taking into account the process of electromagnetic transient variation is set up

and the transient response of PT HV side is quantitatively analyzed. The electromagnetic transient impact effect of switching

PT remanence and single-phase grounding fault on PT HV fuse is discussed respectively. It is concluded that the superposition of closing shock

single-phase grounding fault

remanence or multiple transient processes can bring current shock several times that of the rated current to the high voltage side of PT. The long-term cumulative effect of current shock will affect the fatigue characteristics of the fuse and promote the ‘slow fusing’ of the melt. The analysis results are in agreement with the simulation results of ATP-EMTP. The corresponding technical rectification measures are therefore proposed

which play a positive role in promoting the safe production of the plant and

at the same time

have reference for further optimizing the operation specifications of the plant and improving the production technology and equipment structure of the equipment manufacturers.