Multi-stress Aging Studies on Polymeric Surge Arresters for HVDC Transmission

In recent times, High Voltage DC transmission systems have played an integral role in transmitting a massive amount of electrical energy over very long distances economically. As the transmission system is exposed to the environment, it is prone to lightning surges and atmospheric stresses leading to insulation damage. Metal oxide surge arresters are widely used for protecting the power system from surges. The polymer housing of the arrester has several advantages over ceramic housing. However, it was reported that the polymer housing is affected by environmental factors leading to the failure of the insulation over the period. From the available literature, it was observed that there is no clear understanding of the aging on the polymeric housed surge arrester for the HVDC transmission system. Hence, an experimental investigation was conducted wherein the polymeric housed surge arresters were subjected to the cyclic exposure of the environmental stresses like UV, thermal and humidity similar to the field conditions along with the continuous application of HVDC and the leakage current was continuously recorded at regular time intervals. Visual inspection, hydrophobicity and FTIR (Fourier Transform Infrared) analysis were performed to understand the surface performance of the arresters.