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

<p dir="ltr">In recent years, the power handling capability of EV chargers has been growing to reduce the charging time. In order to enhance the design and efficiency of EV chargers, an in-depth investigation of the losses caused in plug-in EV chargers is needed. This article presents an accurate loss model of a novel single-stage single-phase isolated PFC converter for a bidirectional EV charging application. The EV charger includes a current-fed full-bridge converter with bidirectional switches on the grid side with a swinging boost inductor that is affiliated with a full-bridge converter at the dc-side coupled via a high-frequency transformer. The AC-side current can be controlled to obtain power factor correction with low current total harmonic distortion (THD). The AC-side switches are naturally commutated and attained zero current switching (ZCS) without any external passive components. Additionally, zero current turn-ON is accomplished for DC-side switches to realize a high-efficiency EV charger. This is achieved with a modified control strategy and novel modulation method are adopted for achieving soft-switching operation and bidirectional power flow. To ensure that the proposed EV charger is feasible, experimental results with loss analysis of a 1.5 kVA unit are presented showing that the operation, analysis, and design are perfectly accorded.</p>