Impact of Electrode Shape on the Performance of a Gas Discharge Arrester

This paper deals with the impact of a gas discharge arrester´s electrodes´ shapes on its performance. When after extinguishing the electric arc between the electrodes of the gas discharge arrester and the electric-field strength between the electrodes exceeds the critical value, reignition occurs. Computation of the electric-field strength between the electrodes of the existing gas discharge arresters using the finite elements method shows that electric-field strength reaches its highest values at the edges of the electrodes. It therefore makes sense to reduce the electric-field strength E at the edges of the electrodes by changing the electrodes´ shapes. This also reduces the risk of reigniting the electric arc between the electrodes and improves the arrester´s ability to self-extinguish. The electrodes can be geometrically shaped in such a way that ensures much uniform distribution of the electric-field strength E as possible. This paper describes the model of a gas discharge arrester and the use of a differential evolution optimization algorithm for computation of the more adequate shapes of electrodes. Thus, uniform distribution of the electric-field strength is ensured between the gas discharge arrester electrodes.