Integrated Single-Phase Electric Vehicle Charging Using a Dual-Inverter Drive

Electric vehicles have the potential to reduce emissions from the transportation sector. However, the lack and/or expense of charging infrastructure has slowed their adoption. As such, vehicles are often equipped with small on-board chargers, which serve as the primary charging method. These chargers are discrete devices, with additional power electronics and magnetics, which increase the cost and weight of the vehicle. Another solution is to look at redeploying the existing drivetrain components to serve as an integrated charging system. This work proposes a charging scheme that utilizes the inverter and motor in a dual-inverter drive to directly charge from a single-phase AC grid, at power levels greater than existing on-board chargers. In concept, the dual-inverter drive is shown to be operable similar to a PFC based charger with high input voltage. The challenge addressed in this paper relates to how charging power can be arbitrarily divided amongst the energy sources of the dual-inverter drive. This ability to divide charging power is a critical feature needed to prevent overcharging of the batteries and is also a key feature required in a hybrid energy storage configuration.