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

This presentation describes 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 the maximum power of the PV module, i.e. reducing the low-frequency power ripple across the PV module. This results in an 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 the flyback's primary side, thereby reducing the voltage stress on the main controlling switch. The operating principles and modes of operation of the proposed topology are explained. The 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.