Active Power Decoupling Design of AC-DC Converter for On-board Chargers

Single-phase converters are widely used in On-board Chargers (OBC) of electric vehicles, however, the second-order ripple power of single-phase converter causes second-order ripple voltages on the dc bus. Thus, an active power decoupling method based on single-phase converter is proposed in this paper. The control method, taking single-phase PWM rectifier as the basic converter and adopting buck-boost power decoupling circuit, introduces second-order ripple of DC bus voltage into power decoupling circuit, which acts as compensation of the phase deviation between the command value and the actual value of the second-order ripple current. Therefore, the estimation of the second-order ripple current is more accurate, the power decoupling circuit absorbs the second-order ripple power behind the H bridge more completely, and the DC bus voltage ripple is effectively suppressed. Finally, experiment results of the single-phase PWM rectifier has been given to verify the validity of the proposed method.