Bidirectional DC Circuit Breaker with Improved Performance during Commissioning and Reclosing

DC circuit breakers play a major role in developing and expanding electric power system networks by protecting the network elements from short circuits and overloads. This paper proposes a modified bidirectional z-source dc circuit breaker (MBZSDCCB) by retaining features such as common ground between source and load side terminals, low pass filtering, minimised reflected fault current, and in-corporates the features of reduced starting current, elimination of negative current flow during starting and reclosing, and bidirectional power flow capability. The sizing of the components used in the pro-posed dc circuit breaker is analysed in detail. The MBZSDCCB operation during a short circuit, and commissioning/reclosing instances is demonstrated in SPICE simulation. The issues with the existing z-source circuit breaker are identified by an experimental prototype with a system rating of 120V/3.5A. The performance testing of the proposed MBZSDCCB is validated using simulations in spice and also by developing an experimental prototype of a system rating 400V /10A.