An Isolated Three-Port Interleaved Flyback Boost Converter (ITPIFBC) for Grid-Connected Photovoltaic Applications

In this paper, an Isolated Three-Port Interleaved Flyback Boost Converter (ITPIFBC) operated micro-inverter is presented to interface the Photovoltaic (PV) power generation system with the three-phase power distribution network. The integration of interleaved flyback boost circuit reduces the switching and conduction losses of the converter. The addition of a voltage multiplier circuit in the secondary side of the high-frequency transformer enhances the voltage gain and reduces the voltage stresses of the semiconductor devices used in the rectification part of the circuit. The introduction of a voltage multiplier circuit reduces the required turn's ratio, power rating and voltage rating of the IGBTs and diodes. The duty cycle of the converter controls the power flow between the two independent power sources. The voltage control loop incorporated with the maximum power point tracking algorithm regulates the output voltage of the converter. In this work, the design, operation principle and implementation of the ITPIFBC based micro-inverter are discussed. The dynamic behavior of the proposed micro-inverter is validated by developing the 4 kW, 400 V model in both software and hardware. The simulation and experimental results showed the superior performance of the ITPIFBC converter in boosting the input voltage under various test conditions.