A Three-port Flyback for PV Microinverter Applications With Power Pulsation Decoupling Capability

A novel single-stage photovoltaic (PV) microinverter with power decoupling capability is proposed in this paper. The proposed topology is based on three-port flyback with one port dedicated to power decoupling function so as to reduce the decoupling capacitance, thus allowing for long lifetime film capacitor to be used. Operation principle is analyzed in details. Key design considerations, including key parameter selections, predictive control strategy, and the dc voltage balance control across the power decoupling capacitor, are given in this paper. A 100-W microinverter prototype is built to verify the proposed topology. Experimental results show the proposed topology can achieve power decoupling, while maintaining good efficiency.