Voltage control of a single phase, single-stage, isolated AC-DC converter

With the increasing interest in electric and solar vehicles, compact, efficient and cost effective power solutions are necessary. In this paper a voltage control strategy is proposed for a novel single-stage, isolated, bidirectional AC-DC converter with open loop power factor correction (PFC) for use in on-board electric vehicle (EV) chargers. The analysis presents a mathematical correlation between the modulation phase-shift and the DC component of the DC bus current. The phase-shift is used to control the DC bus voltage. A transfer function is developed for the plant and a PI controller is selected and designed. The modulation scheme is unaffected by the voltage controller therefore open loop PFC is maintained. Simulation and hardware results are presented and confirm the analysis.