Multiple Outputs Converter Design for BMS Integrated Li-Ion Battery Charger Appropriate for Electric Vehicle

This paper presents a high-power density onboard integrated charger with multiple outputs-based H-bridge converters for BMS (Battery Management System) integrated li-ion battery bank used in upgraded electric vehicles. The proposed converter can operate as AC to DC battery charger and to transfer power from the supply grid to multiple battery packs through discrete BMS of the system drivetrain. The BMS controls over voltage, overcurrent, and temperature of the battery pack. This operation will be done more efficiently with the separate power supply to these discrete BMSs. To obtain a high efficiency and high-power density, an HF tapped-transformer is used to meet the requirement of improved system size and reliability by attenuating magnetizing and copper losses with high-switching frequency operation. But the traditional H-bridge circuit suffers from switching loss due to HF operation. To solve this, zero-voltage switching (ZVS) topology was integrated. The impact of the proposed topology and control strategy on the integrated charger power losses, efficiency, and power density has been simulated and analyzed by computer simulation and practical implementation.