2022 IEEE International Conference on High Voltage Engineering and Application (ICHVE 2022)

Existing studies reported that the accumulation and dissipation of surface charge is an important reason for the failure of the turn-to-turn insulation of high-frequency transformers. However, the specific mechanism is unknown. In order to explored the effect of high frequency voltage on the surface charge accumulation and dissipation characteristics of Nomex paper in turn-to-turn insulation of high-frequency transformers, an experiment system is established based on the method of surface potential decay. The accumulation and dissipation characteristics of surface charge are investigated. The results show that the initial surface charge decreases with the increase of frequency and the relationship follows an inverse power function. The decay rate of surface charge shows the Gaussian distribution and exists a frequency-induced inflection point at 1kHz. The above researches can lay a foundation for the analysis of the failure of the turn-to-turn insulation of high-frequency transformers under high frequency stress.