Surface charge decay patterns of insulating polymers based on potential-mapping method

Abstract

The accumulation of surface charge on insulators can lead to electric field distortion. Therefore, measurement of the surface potential decay tendency has proven to be a practical technique for evaluation of the charge dissipation characteristics of dielectrics after corona polarization. The traditional method for evaluation of the surface charge dissipation behavior is based on using a stable suspended electrostatic probe. However, this method was found to be inadequate for analysis of the surface charge transport mechanism because the electrostatic probe was focused only on one point on the sample surface. Therefore, a scanning and mapping technique has been applied in the surface potential measurement that uses a movable electrostatic probe. This technique enables measurement of the complete surface charge distribution profile of the cellular electrets and provides a potential-mapping graph that reflects the exact surface charge distribution and decay tendency of the functional dielectric after discharge. This work describes the phenomenon of the surface charge diffusion pattern based on the mapping of the dynamic surface potential profile from a scanning and mapping graph. This method could be developed into an efficient tool for evaluation of surface charge dissipation on insulating polymers used in high-voltage apparatuses and energy-storage devices.