Control Method of Grid-connected PV-AC module with Decoupling and Energy Storage

In single-phase flyback inverter for grid-connected photovoltaic (PV)-AC module, there is power mismatch on input capacitor between DC power of PV module and AC power of output. This mismatch makes power oscillation and it makes hard to control maximum power point tracking (MPPT). So, decoupling method to eliminate power ripple has attracted interest recently. Also, power generation of PV is depending on surrounding condition like irradiation, temperature etc., so PV generation power is continuously changing and transfers to grid. Therefore, PV generation power cannot be efficiently dealt. To solve this problem, energy storage system is needed. In this paper, flyback inverter having decoupling and energy storage function is proposed and verified by simulation.