Modeling and SVPWM control of quasi-Z-source inverter

Abstract

In today's renewable energy power generation systems, inverters have become key devices connected between energy sources and power grids. The newly presented quasi-Z-source inverter (qZSI) has the unique advantages of boosting DC bus voltage without additional boost link, lower component ratings, as well as constant DC input current compared with the traditional Z-source inverter. To better design the control schemes of this novel topology, the small-signal model is deduced using state variables perturbance mathematical analysis. By this model, the voltage-current closed-loop control of shoot-through duty cycle is designed. The space vector PWM (SVPWM) technique is modified to satisfy the particularity of qZSI. Simulation results certify the correctness and effectiveness of the proposed model and control strategies and demonstrate the applicability of qZSI technology to overcome the disturbances from DC link or AC loads in renewable energy power generation systems.