A Fast DC-Bus Voltage Controller for Bidirectional Single-Phase AC/DC Converters

This paper presents a new dc-bus voltage control technique for single-phase bidirectional ac/dc converters. The proposed controller is able to significantly improve the transient response of the dc-bus voltage control loop and provide a robust and reliable closed-loop control system. In the proposed approach, the dc value of the dc-bus voltage is precisely estimated through a specific adaptive filter. The structure of the proposed filter provides a very fast and robust estimation for the dc value of the dc-bus voltage. In particular, the proposed dc-extraction technique is able to precisely estimate the dc value in presence of double-frequency ripple mounted on top of the dc-bus voltage in single-phase ac/dc converters. Simulation and experimental results demonstrate the superior performance of the proposed closed-loop control system compared to the conventional ones.