This article proposes a modified Q-Z-source (MQZSCB) dc circuit breaker (DCCB) topology that employs a thyristor as the main fault interrupting device and uses a coupled inductor for its commutation during fault. Also, the proposal employs fewer components thereby reducing the weight/volume of the system, which benefits the design aspects of the aircraft. The proposed topology can interrupt the fault approximately within 400µs. And moreover, this topology is advantageous to the existing QZSCB by mitigating the issues of negative current flow through the load especially during reclosing, and unwanted power flow to load during the QZSCB commissioning. The proposed solution also enables reduced current stress on the thyristor during reclosing. A prototype of the system rating 270V/10A has been developed to address the issues and validate the performance of the proposed MQZSCB.
