A Novel Space Vector Modulation Based Control Strategy for Z-Source Inverter

Abstract

In this study, a novel control strategy based on Distributed Space Vector Modulation is proposed to improve dynamic performance of a Z Source Inverter (ZSI) while utilizing only capacitor voltage feedback. Distributed space vector modulation allows ZSI output voltage to be controlled by Z source capacitor voltage with a simple equation. Therefore, only one voltage feedback is enough to control inverter output voltage. Furthermore, zero state is not utilized in the proposed control strategy, so an additional control loop for the modulation index is no longer necessary. Flexible modulation index allows work with flexible dc line voltage and limits the voltage stresses in the inverter switches so ZSI has low cost switches and high efficiency. Moreover, the proposed control method was investigated for both resistive and inductive loads due to ZSI load power factor-dependent characteristics. The effectiveness of the suggested control method is verified by Matlab/Simulink simulations, considering the sudden changes in both the dc source and load level.