Single-Loop Control of Buck Power-Pulsation Buffer for AC-DC Converter System

Power converters interfacing single-phase ac and dc power sources and loads typically require an energy storage device to handle the double-line frequency power ripple. Among the active power storage solutions, called power-pulsation buffers (PPBs), the bidirectional buck topology is popular for its low component count and voltage stress, as well as good performance. However, existing control methods of the buck PPB are rather complex and typically employ at least two feedback loops. This paper presents a simplified, single-loop control of the buck PPB. To achieve the dc-bus-voltage-ripple magnitude below 3 % of the average bus voltage, the voltage feedback loop action was supplemented with current feedforward control. The performance of the proposed control was evaluated on a 1-kW PPB experimental prototype.