Metal oxide surge arrester condition monitoring based on analysis of leakage current components

• Novel study on surge arrester condition monitoring has been performed.
• New indicators based on leakage current analysis have been proposed.
• Medium and high voltage surge arresters have been modeled.
• Voltage fluctuation, third harmonic, over-voltage and varistor aging have been studied.
• There are obvious differences between extracted indicators of different situations.

This paper presents proper indicators for evaluation of the surge arrester condition based on the leakage current analysis. Maximum amplitude of fundamental harmonic of the resistive leakage current (Imr1), maximum amplitude of third harmonic of the resistive leakage current (Imr3) and maximum amplitude of fundamental harmonic of the capacitive leakage current have been used as indicators for surge arrester condition monitoring. The effects of operating voltage fluctuation, third order of voltage harmonic, over-voltage and varistor aging have been investigated to show the ability of introduced indicators for accurate diagnostic of arrester’s conditions. In order to have accurate values of stray capacitors, 3D-FEM has been used. Moreover, surge arrester model for calculating leakage current has been performed in ATP–EMTP. In addition, the signal processing has been done using MATLAB software. This study shows that the introduced indicators are proper criteria for surge arrester condition monitoring.