Thermal Analysis of a Station Class Arrester Model in Continuous Operation and Under the Operating Duty Test

Station class surge arresters play an important role in isolation coordination of transmission systems. To fulfill their protection tasks, thermal stability must be guaranteed. A coupled 2D Finite Element Method simulation approach is proposed. It enables an electroquasistatic-thermal investigation of full-scale arrester models. This implies, on the one hand, a multi-rate time integration scheme. On the other hand, the heat transfer within the arrester air gap is described by means of an equivalent nonlinear material model. Using these approaches, the arrester is, first, simulated at continuous operating voltage. Second, thermal stability is investigated based on the IEC operating duty test. For this purpose, the arrester cooling rate is introduced. It quantifies the thermal stability…