A Universal Battery Charger with Wide Operating Voltage Range and Active Power Decoupling for Electric Transportation

Onboard electric vehicle (EV) chargers face limitations in charging speed, size, weight, and automotive compliance standards, resulting in extended recharge times. To address these constraints, chargers capable of accommodating a wide range of EV battery voltage levels play a crucial role. This paper proposes a wide-voltage-range battery charger with an output range of 120V to 900V, designed to charge existing and future battery packs from conventional single-phase AC supplies (85V to 265V). The proposed charger's buck-boost capability eliminates the need for a high-input filter on the grid side. Additionally, an active power decoupling method is implemented to remove the high-voltage DC link capacitor, thereby reducing space requirements and enhancing DC link voltage quality. A voltage doubler circuit in the charger's back-end minimizes the voltage transformation load on the DC-DC converter. To achieve these objectives, three streamlined control algorithms are employed. The viability of the proposed charger across all practical EV voltage ranges from 120V to 900V is demonstrated through both simulation results, utilizing a 3.3 kW wide-bandgap-based laboratory prototype.