Modified Q-Z-Source DC Circuit Breaker for Next-Generation Electric Aircrafts

The global carbon footprint from the aviation sector is seeing a steep increase in the past half-century. To combat this challenge, electrifying the aircraft is a promising solution. Howbeit, the idea of aircraft electrification is introducing various dc power distribution architectures, increasing the complexity of aircraft electric power systems (EPS). The aircraft EPS is of low voltage and makes the system handle huge currents. Alongside this, the next-generation aircraft power system demands faster and more reliable protection. Solid-state circuit breakers (SSCBs) offer fast fault interruption capability and make the protection system compact. 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 faults. Also, it 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 $400\mu {\mathrm{s}}$. 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 the load during the QZSCB commissioning. The proposed solution also enables reduced current stress on the thyristor during reclosing. A prototype rated at 270V/10A has been developed to address the issues and validate the performance of the proposed MQZSCB.