A Novel Approach to the Ageing Process of Metal Oxide Surge Arresters

Gapless surge arresters constructed with zinc oxide (ZnO) elements, commonly known as Metal Oxide Surge Arresters (MOSA), are widely used for protecting electrical systems from lightning-induced overvoltages. Over time, these arresters are subjected to various environmental and electrical stress factors such as continuous overvoltages, lightning surges, elevated temperatures, pollution, and humidity. These factors contribute to the ageing of the surge arrester, which leads to a degradation in its performance. Thus, assessing the health of a surge arrester is crucial for system reliability, and one of the most effective diagnostic methods is the measurement of leakage current. In this study, the effects of ageing on the performance of MOSA have been investigated through a novel ageing procedure, and its impact on arrester performance has been systematically analyzed. The degradation was evaluated through leakage current measurements, and the results were further validated by conducting standard electrical tests in a high-voltage laboratory.