PROJECT TITLE :

Hybrid Pulsewidth Modulated Single-Phase Quasi-Z-Source Grid-Tie Photovoltaic Power System

ABSTRACT:

A hybrid pulsewidth modulated single-phase quasi-Z-source grid-tie photovoltaic (PV) power system is proposed. The hybrid pulse-width modulation (HPWM) combines the heart beat-width modulation (PWM) and the heart beat-amplitude modulation (PAM). The PWM works when the ac output voltage is not up to the dc supply voltage; otherwise, the PAM operates the one-section quasi-Z-supply inverter (qZSI). The HPWM ends up in the reduction of power loss, and also the quasi-Z-supply capacitance and inductance. An effective management strategy is proposed for the new PV power system to manage the most power point tracking (MPPT) of PV panel, grid-tie power injection, and dc-link voltage. A grid-tie current controller, combining a repetitive controller and a proportional-resonant regulator, achieves strong harmonic suppression, quick dynamic, and 0 tracking error. A 500-W prototype is constructed to verify the new system. Power loss estimation and impedance design are detailed. Experimental tests validate the HPWM, new PV power system with higher efficiency, and the related control methodology.