Analysis and comparison of PWM modulation strategies for Z-source inverter

Z-source inverter is a single-stage inverter,which has buck/boost characteristic.Compared with the widely used voltage source inverter and the voltage source inverter with cascaded boost chopper circuit,Z-source inverter has the advantages of simple structure,high efficiency and system reliability.This paper introduces the operating principle of Z-source inverter briefly,and focuses on PWM modulation strategies for Z-source inverter.Several PWM modulation strategies are presented including simple boost,maximum boost,maximum constant boost,boost modulation with third harmonic injection,short-through subsection based on SVPWM and sine carrier PWM.Through the qualitative analysis and quantity comparison,the paper contrasts the performance of different modulation strategies,sums up their advantages and disadvantages separately from boost capability,voltage stress and current ripple,and lists the parameters comparison table.All these provide a theoretical basis for system selection and application.