Simulation research on improved switched-inductor quasi-Z-source inverter

Traditional Z-source inverter can boost or buck voltage for its unique impedance network, but also has its own drawbacks, such as input current is not continuous, boost capacity is limited, the capacitor voltage stress is large and etc. In order to overcome the shortcomings of the traditional Z-source inverter, a series of Z-source inverters are proposed. In this paper, the topology of three kinds of Z-source inverter are studied, and the principle of boost voltage and the capacitor voltage stress of the switched-inductor quasi-Z-source inverter and the improved switched-inductor quasi-Z-source inverter are analyzed in detail. Based on the theoretical analysis, the Z-source inverter with different topologies is simulated. The simulation results show that the improved switched-inductor quasi-Z-source inverter increases the boost factor, which has an obvious voltage boost ability. And in the case of the same boost effect, a higher modulation index can be used to ensure a good output power quality. Meanwhile, the capacitor voltage stress of improved switched-inductor quasi-Z-source inverter can be reduced and the reliability of the circuit can be improved. Simulation results were presented to demonstrate the new features of improved topology.