Charging Characteristics of Outdoor Polymeric Insulators Under AC and DC Voltages

Surface charge accumulation phenomenon possesses a serious threat to the insulation performance of polymeric insulators. This paper presents the results of different surface charging mechanisms occurring in outdoor polymeric insulator under AC and DC voltage applications. The mechanisms responsible for charge accumulation on the surface of outdoor polymeric insulators are analyzed using experimental results. The charge accumulation is imperceptible under AC voltages even for higher voltages and longer durations. On the other hand, it becomes predominant under DC voltages due to space charges and corona. The polarity and density of accumulated charges under DC voltages depend on the applied voltage polarity, magnitude and the duration of voltage applied. The decay of accumulated charges shows that the charges remain on the insulator surface over a period even after the supply is removed. © 2022, The Institution of Engineers (India).