ANALYSIS OF PWM STRATEGIES FOR A THREE PHASE QUASI Z-SOURCE INVERTER FOR PV APPLICATIONS

Recently, Quasi Z-source Inverter (QZSI) has gained attention due to its advantages of lower component ratings, reduced source stress, reduced component count and simplified control strategies. This paper presents the complete analysis of the three main pulse width modulation strategies namely simple boost, maximum boost and maximum constant boost for a three phase quasi z source inverter. Voltage stress and voltage gain are compared for the three strategies for various modulation indices with a constant boost factor. It has been verified using simulation results that the maximum constant boost technique gives a reduced voltage stress and higher voltage gain compared to the other two PWM techniques