A Multimode On-Board Charger With Multiport Outputs With Reduced Switch Count for EVs

This article proposes a multimode onboard charger with three simultaneous outputs (one ac and two dc in motoring mode; three dc outputs in charging mode) and reduced switch count for electric vehicles. In multimode operation, it behaves as an inverter in motoring mode and battery charger in charging mode. Thus, eliminates the requirement for two separate converters resulting in reduced overall system's switch count. In motoring mode, inverter drives the brushless dc (BLDC) motor using high-pulsewidth modulation-low-
on
switching scheme. In the charging mode, the system is transformed into a front-end converter with half-bridge LLC converter which maintains unity power factor (UPF) at the source and charges the battery with constant-current constant-voltage optimal charging technique utilizing a single control loop. The design equations of the converter are derived and its performance with cost comparison are presented. The operation of the proposed charger is validated using a laboratory-developed prototype to charge a 36 V battery from 120 V, 50 Hz supply while maintaining UPF in charging mode; and driving a 1000 W, BLDC motor in motoring mode. In addition, it generates 48 and 12 V for auxiliaries, thereby eliminating the need for an extra 12 V battery and its charger.