Optimal design process for three-port flyback inverter with active power decoupling

In this paper, the design process for applying 250[W] micro-inverter using novel active power decoupling circuit with auxiliary winding are proposed. This type using three-port transformer for active power decoupling stores the surplus energy in decoupling capacitor and supplies sufficient energy to grid. Conventional decoupling circuit is applied in single phase grid connected micro-inverter especially single-stage configuration like flyback-type DC-AC inverter. In this passive power decoupling method, power decoupling capacitor for flyback inverter is fairly large so electrolytic capacitor is essentially required. However the decoupling capacitor is replaced with film capacitor by using active power decoupling(APD) method, thus the overall system can achieve smaller size and longer lifespan. Proposed three-port flyback inverter is verified by design optimization and simulation.