An Integrated Design of the Z-Source Circuit Breaker and the Cuk Converter

DC-DC converters and DC solid-state circuit breakers are critical to the stable operation of DC microgrids. However, they can interact with each other when cascaded, causing problems such as the inability of circuit breakers to isolate short-circuit faults or the amplification of converter output ripple. In order to solve the above problems, an integrated design scheme based on Z-source DC solid-state circuit breakers and DC-DC converters is proposed and applied to the Cuk converter in this paper. The proposed topology achieves functional integration by multiplexing the coupled inductors in Z-source circuit breaker with the inductor in Cuk converter. This scheme guarantees two performance targets, reducing the size footprint and achieving low-pass filtering characteristics. By comparing and analyzing the operation condition in steady state of the proposed topology with the Cuk circuit, the mathematical model is established, and its feasibility is verified by theoretical derivation. Finally, the simulation model is built on MatLab/Simulink, and the simulation results prove the correctness of the theoretical derivation.