Nonisolated On-Board Charger Capable of Reducing Common-Mode Leakage Current and Balancing Voltage of Y-Capacitor on High-Voltage Battery

This article proposes a novel nonisolated on-board charger (OBC) that can reduce common-mode (CM) leakage current and balance the voltage of Y-capacitors on a high-voltage (HV) battery. The proposed nonisolated OBC is configured with an inverter power factor correction circuit and a nonisolated LC series resonant converter (SRC). A new pulsewidth modulation method is applied to inverter power factor correction (IPFC), which can balance the voltage of Y-capacitors and prevent the misdiagnosis of HV battery isolation breakdown by the battery management system (BMS). Additionally, a nonisolated LC SRC is applied to the dc/dc stage to reduce the CM leakage current. The effectiveness of the proposed OBC is verified by prototype circuit experimental results.