Analysis of the influence of unequal current distribution on the heating of parallel connected LV MOV surge arresters

摘要

In low-voltage (LV) electrical networks metal-oxide varistor (MOV) surge arresters connected in parallel are often used against overvoltages. The paper presents the results of laboratory experiments, duhng which pairs of parallel connected MOV surge arresters were subjected to surges of specified energy. The tests determined energy distribution between surge arresters for AC burst voltage stresses, temperatures recorded on their surface using contact sensors and temperature distribution images (IR thermograms). The analysis of results and conclusions are also presented.