Full-bridge Current-fed PV Microinverter with DLFCR Reduction Ability

A simple current-fed full-bridge converter (CF-FBC) is proposed as a prestage for photovoltaic (PV) microinverter after comparing it with the existing topologies. A modulation strategy based on the CF-FBC with two control freedoms is presented in this article. One freedom is the boost duty cycle, which controls the voltage of the PV panel. The power duty cycle is other freedom, which controls the voltage in the low-voltage side. The operational principle of the proposed CF-FBC is analyzed. A control strategy composing three closed loops is proposed. The regulator parameters are designed based on the small signals model of the converter. The experimental results verify the effectiveness of the proposed converter and its corresponding modulation and control strategy.