Power decoupling method for single-phase buck-boost inverter with energy-based control

This paper presents a single-phase differential buck-boost inverter with an energy-based control, which adapts to various DC input voltages and achieves active power decoupling without additional devices. The proposed energy-based control technique calculates the duty cycles of the switches according to the energy demanded by the load. To achieve active power decoupling, the double line-frequency pulsating power is controlled to deliver to the output capacitors instead of to the DC side. An active damping control method is also employed with the energy-based control to suppress the voltage and current pulsation at the resonant frequency. Simulation and experimental results show that the proposed control technique achieves successful power decoupling with substantial reduction of second-order component in the DC current, and effectively mitigates the ripple current at the resonant frequency.