On-Board Integrated Buck and Boost Charger with Constant-Current and Constant-Power Charging Modes

The development of integrated on-board charger has improved the space utilization and conserved hardware resources in electric vehicles (EVs). However, many chargers only have buck or boost charging mode. That may cause the EVs to be unable to match different external charging voltage. Therefore, this paper proposes an integrated on-board charger with buck and boost charging function. The charger reconfigures the inverter and motor winding into a Cuk converter. It does not affect the driving function of the motor, meanwhile, that also gives consideration to the charging function. In addition, both the input current and the output current are continuous when boost or buck charging. And two charging modes are proposed. 1) Constant-current charging mode which keeps the battery current constant when charging. 2) Constant-power charging mode which makes the input power constant. The paper analyzes the whole process and control mode of the two charging modes. Finally, simulation realized the fast and healthy charging for supercapacitors.