Analysis of Temperature Fields of a 10kV Electromagnetic PT Under Ferroresonance

Electromagnetic potential transformer(PT) may undergo ferroresonance when subjected to external disturbances, which causes overvoltage and affects the stable operation of the power system. In order to provide reference advice for the installation and monitoring of the sensor, the temperature field of 10kV electromagnetic PT was simulated by utilizing the finite element method. In this paper, after establishing a three-dimensional model, joule loss, eddy current loss and hysteresis loss were calculated as heat sources, and then the temperature field distribution was simulated. Subsequently, the differences before and after the ferroresonance were compared to analyse the influence of the ferro resonance and inferred the location where the abnormal temperature rise occurs. The simulation results showed that the highest temperature of the shell is located at the side closest to the heat source, where the epoxy resin is the thinnest and most sensitive to temperature changes. Therefore, the temperature sensor should be mounted at this location, where the abnormal temperature rise can be detected quickly. This study not only will provide suggestions for the installation and monitoring of sensors, but also will lay a foundation for the realization of the “self-healing” function of the robust smart grid, and improve the reliability and security of the grid operation.