Flyback configuration based micro-inverter with distributed MPPT of partially shaded PV module and energy recovery scheme

200W PV modules consist of two or three bypass diodes in the junction box to bypass the shaded portions of the sub-modules when partial shading of the PV module occurs. This results in multiple peaks in the Power-Voltage characteristics of the PV module. This paper proposes a novel flyback configuration based micro-inverter capable of extracting maximum power from the PV module even during partially shaded conditions. This is achieved by incorporating a novel equalization circuit across the module. The equalization circuit consists of a network of series combination of diode and a `special´ winding derived from the secondary side of the flyback transformer based micro-inverter. The equalization circuit is also capable of energy recovery from the primary side leakage inductance, when the main switch is turned off. The proposed topology consists of features such as extraction of maximum available power, energy recovery capability and dc to ac conversion. The effectiveness of the proposed topology is investigated and confirmed for a partially shaded PV module along with the energy recovery. Operating modes, analysis, control strategy and simulation results of the proposed topology are included.