Single phase solar PV module integrated flyback based micro-inverter with novel active power decoupling

This paper presents a flyback based single phase solar PV integrated micro-inverter with a novel active power decoupling scheme (APDS). The APDS bridges the power mismatch between the instantaneous grid power and maximum power of the PV module i.e. reducing the low frequency power ripple across the PV module. This results in enhanced maximum power point tracking (MPPT) capability of the PV module while drastically reducing the input capacitor size. With the input capacitor size reduced, it may be replaced by a film capacitor, which increases the system's reliability. The APDS also helps with the recycling of the leakage energy of flyback's primary side, thereby reducing the voltage stress on the main controlling switch. The operating principle and modes of operation of the proposed topology are explained. Effectiveness of the proposed micro-inverter topology is tested with low values of PV side and decoupling capacitance in reducing the low frequency ripple in the PV voltage and clamping the voltage spike across the main switch. Analysis, control and simulation results of the proposed topology are presented.