Single-phase multifunctional onboard battery chargers with active power decoupling capability

In this paper, a single-phase multifunctional onboard battery charger for electric vehicles (EVs) is proposed, where the active power decoupling capability is provided by utilizing the low voltage (LV) battery charging circuit. For this, the buck converter for the LV battery charger is used as an active power decoupling (APD) circuit while the high voltage (HV) battery is connected to the grid, by which the inherent second-order ripple power component of the single-phase charger is filtered out. Hence, small film capacitors can replace the large electrolytic capacitors, leading to the reduction of cost and the volume of the charger for EV applications. The effectiveness of the proposed charger is verified by experimental results.