Modified T-Source Circuit Breaker for Bidirectional Operation in MVDC

Z-Source circuit breaker is immersing as an attractive research area on the DC system protection because of its property of automatically responding to faults without the external control system. With the first proposed classical Z-source breaker, many more modifications have been made to minimize the operating time as well as to facilitate bidirectional operation. This paper modifies the previously proposed T-source breaker for the bidirectional operation which can be applied in the MVDC system where bidirectional power flow between different sources and load is required. The scheme uses the arrangement of a coupled-inductor, capacitor, and diodes to provide the protection against short-circuit or overload condition during forward and reverse flow while maintaining the same direction of current flow for T-source breaker. Firstly, circuit design is done to estimate the proper size for the breaker components and then overload and short circuit condition is simulated for single-mode power flow on simulation. Finally, the analysis of each condition is presented with validation on MATLAB.