Evaluation of integrated active filter auxiliary power modules in electrified vehicle applications

In electrified vehicles, distinct harmonic currents and corresponding ripple voltages exist mainly on the DC-links of the traction inverter and single-phase high voltage (HV) battery charger. Those harmonic currents are normally filtered by 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. This paper explores and evaluates a new method for reducing the bulk film capacitors in electrified vehicles. It applies a proposed integrated active filter auxiliary power module (AFAPM) to fulfill both the low voltage (LV) battery charging mode and the active filtering mode functions. Hence, the integrated AFAPM can achieve the AF function without extra power switches, heat sinks, and corresponding gate drivers. Therefore, the proposed method can reduce the cost and volume of the power electronics system in electrified vehicle applications. The evaluation results show that using the AFAPM to mitigate the single-phase HV battery charger´s second-order harmonic current is promising and easy to achieve.