Surface Charging of Polymeric Nanocomposites under AC Excitation

Surface charging of insulating materials is one of the factors which adversely affects the operating performance of an electrical system. The underlying cause of surface charge is the formation of plasma due to corona discharges originating in high-field stress regions. The accumulated charge on the insulator surface interrupts the local electric field, which may lead to the system malfunctioning. Silicon rubber (SiR) is an extensively used basic insulating material. The addition of fillers enhances the insulating properties of SiR and affects the surface charge dynamics. A lot of research has been done on surface charging of unfilled and filled SiR for DC excitation, but for AC excitation, it is still sparse. This work analyses the surface charge dynamics of unfilled and filled SiR for AC excitation. It was found that the addition of fillers, along with the polarity reversal in AC stress, governs the charge accumulation on the sample surface.