Efficiency improvement of grid-tied inverters at low input power using pulse skipping control strategy

Pulse skipping control strategy is applied to improve efficiency of grid-tied inverter at light load. To maximize the efficiency of pulse skipping operation mode, three key parameters are identified and can be optimized based on a loss model, which is developed to find the maximal efficiency points using three-dimension searching technique. To reduce the potential of pulsating on the power grid, the synchronization of the power pulse to the grid is addressed by varying the DC bus voltage window, namely varying the upper and lower DC voltage limits. A 200 W prototype is setup to verify the proposed strategy. The experimental results show that the proposed strategy greatly improves the efficiency at light load and match the simulation results fairly well, thus verifying the validity of the proposed optimization method for pulse skipping.