A grid-connected hybrid cascaded H-bridge inverter

To satisfy the need of high performance, a grid-connected hybrid cascaded H-bridge single-phase inverter is proposed. The topology of the inverter has different DC voltages, and a modulation method minimizing the switching loss is applied. In order to improve the control performance, the phase lock loop (PLL) based on generalized second-order integrator is adopted. A current controller based on Proportional-Resonant (PR) regulator is also employed. The feasibility and effectiveness of the cascaded grid-connected inverter system are verified by simulations and experiments.