Influence of Low Frequency Oscillation on the Fuse of Potential Transformer

In the medium voltage distribution network grounding system through arc suppression coil, the fuse failure of potential transformer on the high-voltage side occurs frequently, including the fuse during startup and grid connection, the fuse during operation and the fuse during shutdown, which will have a direct impact on the action accuracy of secondary equipment such as measurement, metering and protection. The statistical data show that the fuse on the high-voltage side of potential transformer in most hydropower stations is blown during unit startup, Therefore, this paper takes the fuse fusing event of the high-voltage side of the 18kV potential transformer in the hydropower plant as the research object, focuses on the impact of the system low-frequency nonlinear oscillation caused by the single-phase grounding fault of the unit system on the fuse fusing of the high-voltage side of the potential transformer, and uses the EMTP electromagnetic transient simulation program to establish the fuse fault simulation model, which lays a foundation for the subsequent research on the method of restraining the fuse fusing of the high-voltage side of the 18kV potential transformer in the hydropower plant.