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 considering to improve dynamic performance of Z Source Inverter (ZSI) while obstructing high voltage stresses on inverter switches and high loss. Distributed space vector modulation lets 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, no zero state is utilized in the proposed control strategy so an additional control loop for modulation index is no longer needed. Flexible modulation index lets work with flexible dc line voltage and it makes it possible to limit voltage stresses across inverter switches so ZSI has low cost switches and also high efficiency. Moreover, the proposed control method has been investigated for both resistive and inductive loads due to ZSI load power factor depended characteristics. Effectiveness of the suggested control method is verified with Matlab/Simulink simulations considering sudden changes both in dc source and load level.