Electrical Power Dissipation on the Surface of a Ceramic Insulator under Pollution Condition

An investigation is carried out on a contaminated insulator to determine the effects of acid rain pollution on its performance. The polluted insulator is modelled using a Finite Element Analysis (FEA) software. Two cases of pollution condition and one case of unpolluted insulator condition were investigated. When voltage was applied to the insulators, it was observed that higher power dissipation characterized the narrow edges of the insulator as compared to other regions in both cases of pollution. Similarly, high electric field stress was experienced in these regions, confirming that the power dissipated in these parts is directly proportional to the electric field strength. Due to these conditions, these areas become prone to dry band formation and partial discharges (PD). This is not the same for the unpolluted insulator were low power dissipation was observed; implying that the conditions experienced were caused by the pollution. Results from this work are expected to be applied in asset management of high voltage (HV) equipment, in detection of PD and predictive maintenance activities, thereby mitigating insulator flashover resulting from pollution and increase the reliability of power transmission systems and railway catenary networks.