Modified bi-directional Z-source breaker with reclosing and rebreaking capabilities

A modified topology of a bi-directional z-source circuit breaker with coupled inductor (Bi-CZSB) with reclosing and re-breaking capabilities is introduced in this paper. The proposed breaker can operate with a single coupled inductor for bi-directional power flow. Therefore, the size of the inductor is optimized to 50%, thus the total cost of the breaker is minimized. A brief overview of reclosing and re-breaking requirement is discussed in this paper. The breaker is intended to perform operating duty of reclosing and re-breaking based on the field conditions. Most of the times, faults in the overhead system are due to the temporary transient conditions. Such faults get cleared after the breaker opens and disconnects the circuit. Very few faults lead to permanent damage to the system where they are required to be isolated. Operation of previously proposed Bi-CZSB is discussed under reclosing and re-breaking conditions. Necessary modifications are introduced to perform the reclosing and re-breaking operation in modified Bi-CZSB. Simulation results are presented verifying the desired performance.