Power Decoupling Method for Single Stage Current Fed Flyback Micro Inverter

Among different micro inverter topologies, single stage micro inverters duo to their lower component, low cost and simple control structure are paid more attentions. One of the biggest problem in single phase micro inverter is power ripple in twice frequency of line. This phenomena causes voltage and current ripple in the side of PV so that designing MPPT controller becomes very hard. To eliminate power ripple (power decoupling) in conventional micro inverters, large electrolytic capacitors are used in parallel of PVs. Drawbacks of electrolytic capacitors are large ESR and lower life cycle in comparison of other type of capacitors. In this paper, a power decoupling method for Single stage flyback based current fed micro inverter is presented. By this method, the required capacitance for power decoupling and current stress of semiconductors are decreased which film capacitors can be used instead of electrolytic. The effectiveness of this method is confirmed for 100w micro inverter by PSIM simulation.