An Accurate Loss Model of Single-Stage Single-Phase Isolated PFC Converter for Bidirectional Plug-in EV Charger

This paper proposes an accurate loss model for a novel single-stage, single-phase isolated PFC converter designed for bidirectional EV charging applications. The proposed EV charger features a current-fed full-bridge converter with bidirectional switches on the grid side, integrated with a swinging boost inductor connected to a full-bridge converter on the DC side, coupled via a high-frequency transformer. The AC-side current is controlled to achieve power factor correction with low total harmonic distortion (THD). The AC-side switches are naturally commutated, enabling zero current switching (ZCS) without the need for any external passive components. Furthermore, zero current turn-on is achieved for the DC-side switches to enhance the overall efficiency of the EV charger. This is accomplished through a modified control strategy and a novel modulation method that ensure soft-switching operation and bidirectional power flow.

Keywords: EV Charger, Wide Bandgap Device-Based EV Charger, Single-Stage Bidirectional Charger, Power Factor Correction (PFC), Isolated AC/DC Converter.