Current control of Z-source inverter for hybrid energy storage system of mine-used electric vehicle

Aiming at problems of low voltage gain, low power density and low conversion efficiency of traditional Z-source inverter or single-switch inductor Z-source inverter used in hybrid energy storage system of mine-used electric vehicle, a novel Z-source inverter was proposed. Modular switch coupled inductance units based on array magnetic integration technology is used to replace inductance of traditional Z-source inverter, so as to improve power density and voltage gain. By introducing auxiliary soft switch branch to realize zero-voltage switch of power devices, conversion efficiency is improved. Hybrid energy storage system based on the novel Z-source inverter was modeled. Through pole analysis, one pair of conjugated poles causing the system to oscillate and frequency of system oscillation were found, current controller parameters are designed with the model, and design criteria of proportional and integral parameters of current controller were derived. The simulation and experimental results verify correctness of the design criteria of the current controller.