Investigation of the circuit breaker reignition overvoltages caused by no‐load transformer switching surges

When an unloaded transformer or motor is switched under certain conditions, the circuit breaker can be exposed to a re‐strike effect that leads to voltage escalation. The effect of reignition depends not only on the type of circuit breaker, but also on the surrounding network. In this paper we describe a detailed model of all system components, which is extended where necessary, for the calculation of transients caused by the vacuum circuit breaker switching surges. Especially the transformer modelling is explained in detail for a broad frequency range because of a very complex transient behaviour. The system configuration consisting of a circuit breaker, a cable, a transformer and arresters is observed and modelled by means of some provided measured data. The results of some models are compared with measurements. The models have been imbedded into the Alternative Transient Program (ATP). The program developed here can be widely used for studies of transient recovery overvoltages caused by interruption of transformer steady‐state and inrush currents if the measured data and parameters for the system components are known.