A Novel Single Phase Modified Quasi-Z-Source Inverter Circuit Design and Analysis

Abstract

This study presents a novel single phase modified quasi-Z-source inverter (qZSI) with high boost voltage conversion ability by using an additional switching device across the impedance network. Compared with traditional qZSI, the boost ability of the presented circuit is increased. Furthermore, the total harmonic distortion (THD) for the voltage and current at the output is reduced because of a modified unipolar pulse width modulation (PWM) technique adapted for the qZSI. Therefore, the overall efficiency of the circuit is improved. The operation principle of the single phase modified qZSI is analysed using theoretical calculations. Simulations are performed to prove the effectiveness of the high boost voltage conversion ability for different modulation indexes using Matlab/Simulink. The applied modulation technique is compared with the traditional PWM control techniques to show reduced THD value which is very close to the IEEE distortion limit. A laboratory prototype is developed to validate the proposed theory.