Comparative study of cycloconverter based double-ended isolated microinverter topologies for solar photovoltaic AC (SPVAC) module

This paper presents a comparative study of double-ended isolated full-bridge, half-bridge, and push-pull high frequency (HF) transformer isolated microinverter topologies for solar photovoltaic AC module (SPVAC) application. In the proposed microinverters, a simple Sinusoidal Pulse Width Modulation (SPWM) is employed for front-end devices, whereas the half-bridge cycloconverter devices on secondary operate at line frequency, thus providing direct high frequency ac (HFAC) to line frequency ac (LFAC) conversion with transformer isolation. From the comparative study, it is observed that half-bridge is cheaper than the other two topologies and has comparable efficiency to full-bridge. Thereby, for experimentation the half bridge microinverter has been selected. Experimental results are presented on 250 W half-bridge microinverter for to demonstrate its performance.