Stability Predictions of Zinc Oxide Surge Arrester by Employing Finite Element Solutions

A well-designed metal oxide (ZnO, zinc oxide) surge arrester offers a desired nonlinear characteristic to ground the surges and overvoltages at the safest level. Although a revolutionary work has been carried out in material research, the apparatus still suffers from a few limitations e.g., nonidentical ZnO block characteristics and its nonuniform thermal and structural behaviour. It becomes imperative to test device prototype for their electrical, mechanical and thermal performances. The cost for actual testing is huge and varies with the rating of the surge arrester. The software-based technique offers near actual behaviour assessment / functional visualization of the lightning arrester prior to prototype making and saves on costly testing set-up and charges. In this paper, the metal oxide arrester has been modelled and analysed using finite element (FE) technique. Standard tests for surge arresters have been simulated with various configurations and these are analysed in the electrical and mechanical domain. The results and analysis of these simulated tests under normal and transient conditions are presented and discussed.