A hybrid DC circuit breaker for DC microgrid based on zero current switching

Abstract

In this paper, a hybrid DC circuit breaker based on natural Zero Current Switching for DC microgrid is proposed. In the DC networks, arc quenching is a dramatic challenge due to lack of zero crossing of current, which results in corrosion and reduction of circuit breaker lifetime. The hybrid circuit breaker conducts the current using a mechanical switch in normal condition. In fault condition, counter current of a discharging capacitor makes mechanical switch to experience zero crossing condition. Therefore, the arc can be quenched safely. Also, the fault current with relatively higher impedance can be interrupted using zero voltage switching. The proposed breaker structure is described and its performance is evaluated using different simulations.