Study of defects based on simulation of action currents of EM multi-column parallel arresters

The metallic return arrester(shortened as EM arrester) often adopts a multi-column parallel structure. The uneven current coefficient reflects its current sharing characteristics, affecting overall performance. This paper first simulates and analyzes the action characteristics of the EM arrester under typical fault conditions. As the deteriorated column volt-ampere characteristics decrease, the uneven current coefficient increases, accompanied by increases in the deteriorated column’s amplitude, head/tail slope, and absorbed energy. The head time remains stable, while the tail time varies irregularly. Based on the correlation analysis, the amplitude, head/tail slope, and absorbed energy are selected as the feature parameters, and their respective scale factor thresholds are calculated to be 1.098, 1.098, 1.099, and 1.101, respectively. The thresholds provide a theoretical basis for the EM arrester’s online monitoring and early warning, which is valuable for ensuring equipment safety and enhancing system operation stability.