Parameter Design of Capacitor for Z-source Circuit Breakers Considering the Influence of Line Resistance and Inductance

The line inductance and resistance will interact with the energy storage capacitor of the Z-source circuit breakers in practical applications, which will increase the possibility of mal-operation and non-operation of Z-source circuit breakers. Therefore, line parameters should be considered in the parameters design process. In this paper, the load capacitance is equivalent to a time-varying voltage source, and in this way the third-order circuit is turned into a two-order circuit. An accurate model of the circuit breaker is built based on this hypothesis. The Z-source capacitor value designed by this model is compared with the previous model. The results of simulation and experiment verify that the new model proposed in this paper is more accurate than the previous one and can effectively avoid mal-operation and non-operation of Z-source circuit breakers.