Modeling SF6 circuit breaker for shunt reactor switching transient analysis

The transients generated by switching off the shunt reactor via a SF₆ circuit breaker may cause power quality problems in the transmission system. In traditional analyses, the shunt reactor switching simulation usually uses an ideal switch model instead of a more realistic model. As a result, such ideal switch model cannot reflect the actual transient phenomena caused by the energy interaction between contacts of the circuit breaker. In the study, a practical SF₆ circuit breaker model which is in combination of Mayr´s arc model, EMTP TACS switch control with dielectric strength control, and a voltage comparator is proposed to simulate the switching process of the shunt reactor and to observe the associated transient behaviors. Two test cases are performed to validate the usefulness of the proposed model. In comparing with the estimated and measured data, simulation results show that the proposed circuit breaker model is relatively accurate to predict the shunt reactor switching transients.