Phase-shifted pulse-width-amplitude modulation for quasi-Z-source cascade multilevel inverter based PV power system

A phase-shifted pulse-width-amplitude modulation (PS-PWAM) is proposed for quasi-Z-source cascade multilevel inverter (qZS-CMI) applied to photovoltaic (PV) power system. The detailed modulating principle is disclosed. A switching loss model is built to evaluate the qZS-CMI's power dissipation when the PS-PWAM and the traditional phase-shifted SPWM (PS-SPWM) are respectively employed. The simulation and experimental results verify that the proposed PS-PWAM has a lower power loss and higher voltage utilization than the traditional PS-SPWM for the qZS-CMI.