Dual Active Bridge-Based Full-Integrated Active Filter Auxiliary Power Module for Electrified Vehicle Applications with Single-Phase Onboard Chargers

In single-phase AC onboard chargers for electrified vehicles, second-order harmonic current and corresponding ripple voltage exist on the DC bus. The low-frequency harmonic current is normally filtered using a bulk capacitor or an additional active filter (AF) circuit. This presents an obstacle for improving the power density as well as reducing the cost. In this paper, a dual active bridge (DAB)-based full-integrated active filter auxiliary power module (AFAPM) is presented so that when the high-voltage (HV) battery is charging, the DAB converter acts as an active filter; and when the low-voltage (LV) battery needs to be charged, the DAB converter works as a LV battery charger. Therefore, the required DC-link capacitance in the HV battery can be reduced significantly and, hence, the cost and volume of the dual-voltage system in the electrified vehicle applications can be reduced. The effectiveness of the proposed method is verified by simulation results.