Integrated active power filter auxiliary power modules for electrified vehicle applications with single-phase on-board chargers

In single-phase on-board charger for the electrified vehicles, second-order harmonic currents and corresponding ripple voltages exist on the dc bus. The low-frequency harmonic current is normally filtered using a bulk film capacitor or additional active power filter (APF) circuit. This presents an obstacle for improving the power density as well as reducing the cost. This paper presents a new method for reducing the bulk capacitor in the single-phase charger. It applies the low voltage (LV) battery charger auxiliary power module (APM) as an APF to filter the low-frequency harmonic currents in the high voltage (HV) battery charger when the HV battery is charging. Hence, the integrated APM can achieve the APF function without extra power switches, heat sinks and corresponding gate drivers. Therefore, the proposed method can reduce the cost and volume for the dual-voltage charging system in the electrified vehicle applications. The effectiveness of the proposed method is verified by simulation results.