A High Step-up DC-DC Converter With Interleaved and Coupled Inductor Based on Topology Combination

Aiming at the application scenarios of high voltage transmission ratio in distributed generation systems, and aerospace and electric vehicles, this paper proposed a novel high step-up DC-DC converter with interleaved and coupled inductor. The proposed circuit structure adopted the form of topology combination for interleave. On the one hand, it enlarged the capacity of the converter; on the other hand, the input current ripple was reduced. Also, when the turns ratio was the same, and the power of coupled inductor of two-phase converter was equal, there was no power imbalance problem. By integrating voltage doubled capacitors, the voltage gain was further improved and the voltage stress of power devices was reduced. Therefore, low voltage level and high performance power devices could be used to improve the operating efficiency of the converter. The passive clamping circuit recycles the energy of the leakage inductor, which reduced the voltage spike of the switches. Moreover, the leakage inductor alleviated the reverse recovery problem of the diodes and improved the reliability of the converter. The operating principle and steady-state performance of the converter were analyzed in detail, and a 1000W prototype was built for verification. The measured maximum efficiency was 97.2%, and the efficiency at full load was 94.5%. The experimental results verified the correctness of the theoretical analysis and the feasibility of proposed converter topology. © 2021 Chin. Soc. for Elec. Eng.