Modeling SF6 Circuit Breaker for Characterizing Shunt Reactor Switching Transients

The black-box arc models are commonly used for describing the interaction between a switching arc and the surrounding circuit during a circuit breaker interruption process. This paper proposes an extended Mayr´s equation based arc model for the SF₆ circuit breaker to characterize the transients associated with switching off a shunt reactor. The proposed model includes Mayr´s arc model with estimated parameters input, a time-controlled switch, and a dielectric recovery voltage control unit. From the transient simulation aspects, the paper not only provides the guidelines for estimating parameters required for Mayr´s equation to simulate the arc dynamics, but also describes a method for modeling post-arc behavior that cannot be simulated by conventional black-box models. Several study cases are performed to show the usefulness of the proposed model. Results obtained are compared with the measured and calculated data. It shows that the proposed SF₆ circuit breaker arc model is relatively accurate for characterizing the shunt reactor switching transients.