Charge distribution on polymer insulator surface under AC voltage

Charge accumulation on an insulator surface under AC electric field is uncertain and is different from DC. In this paper, a method of extracting the phase of voltage truncation time is proposed. The characteristics of charge distribution on an insulator surface under AC voltage is obtained, and the relationship between the voltage phase and the surface charge distribution is investigated. The measurement results of charge distribution and the microscopic discharge process are compared and analyzed which can overcome the deficiency of the traditional off-line measuring method. In addition, the effect of voltage amplitude and insulator material characteristics on the surface charge are studied. It is shown that the charge distribution on an insulator surface shows a three-tier concentric circular structure, and the distribution characteristic of the charge is closely related to the phase of the AC voltage truncation time and the insulation material. The charge density is also affected by the voltage amplitude.