Charge migration of multilayer oil paper on the process of partial discharge under AC voltage

• Main Authors: Bo Gao, Yixuan Li, Kai Liu, Xiaonan Li, Yan Yang, Guangning Wu
• Format: Article
• Language: English
• Published: Wiley 2021-07-01
• Series: IET Generation, Transmission & Distribution
• Online Access: https://doi.org/10.1049/gtd2.12157

Abstract As one of the main reasons for the deterioration of Nomex paper and charge migration, partial discharge (PD) plays a critical role during PD degradation. In this study, the PD characteristics of multilayer oil paper are focused on. In order to explore the characteristics of charge migration, the experiments of the relative permittivity, conductivity, isothermal surface potential decay, scanning electron microscopy and Fourier infrared spectroscopy have been carried out. The results show that the discharge branches of the second layer are two and three times longer than those in the first layer. In addition, the trap level of the first layer for PD degradation samples increases with the degree of PD degradation. The charges captured by deep traps provide seed charges for PD on the surface of the first layer. The charge transportation will accelerate the formation of shallow traps. The charge distribution and shallow traps contribute to the expansion of discharge branches.