Harmonic Analysis of Metal Oxide Surge Arrester Leakage Current Considering Fan-Shaped Type Pollution Effect
Mohammad Hossien Teymourian, Seyyedmeysam Seyyedbarzegar, Masume Khodsuz
Abstract
This article investigates the leakage current (LC) analysis of metal oxide surge arresters (MOSAs) under both uniform and fan shape as a nonuniform pollution conditions and at different humidity levels (H) through experimental methods. The main contribution of this article is examining the effect of fan-shape pollution on MOSA LC. Increasing the degree of nonuniformity (D) decreases the MOSA LC and its harmonic components. The experimental results show that D has a greater impact on reducing the harmonic components of the resistive LC, with a lesser effect on the fifth-order harmonic (Ir5) compared to the first- (Ir1) and third-order harmonics (Ir3). The first-, third-, and fifth-order harmonics of the resistive LC demonstrate an approximate linear relationship with D. Therefore, D can influence on condition monitoring criteria, potentially leading to incorrect diagnosis of the MOSA condition. For instance, the variation of pollution from uniform to D = 0.75 causes a twofold decrease in the Ir3/Ir5 criterion.