An Experimental Study to Investigate the Condition of Metal Oxide Surge Arrester under Polluted Environment

In this paper an experimental study has been performed to assess the condition of MOA under dry and polluted environment based on internal leakage current information. Metal Oxide Surge Arrester (MOA) is important equipment in electrical power system as it protects other valuable equipment from electromagnetic transients. Therefore, internal leakage current or current flow through the volume of MOA has been recorded in this paper based on IEC 60507. For better understanding of the condition of MOA resistive component of leakage current has been extracted using improved phase shift current method. The change in nonlinear V-I characteristics of MOA with respect to exterior polluted layer is also investigated based on the resistive leakage current signal.