An Efficient Hybrid DC Circuit Breaker With Mechanical and Power Electronics Based on Current Commutation

The conventional mechanical and power electronic (MPE) hybrid dc circuit breakers (DCCBs) face challenges in balancing efficiency and performance. This study proposes an efficient MPE hybrid DCCB to address these limitations. The proposed topology reduces ON-state losses to a negligible magnitude utilizing only mechanical switches, such as the residual current switch (RCS), mechanical fast switch (MFS), and monostable mechanical switch in the main branch. Additionally, it reduces the number of semiconductor devices by employing a series connection between the MFS and the main current breaker (MCB). The dc interruption capability of the proposed MPE hybrid DCCB topology was verified through simulations based on an equivalent electric circuit, while its medium-voltage (MV)-class performance was confirmed through dc interruption tests. The proposed MPE hybrid DCCB offers an effective solution for improving the performance and reliability of dc power systems.