A Compact 17.6 kW Single-/22 kW Three-Phase Compatible EV Charger: Analysis of Active Power Decoupling, Wide Voltage Range Operation

In this article, a single- and three-phase compatible battery charger with active power decoupling (APD) is proposed. The two-stage system consists of CLLC resonant converter for dc–dc converter and integration of two-level inverter (three-phase) and three-phase interleaved totem-pole inverter (single-phase) for ac–dc converter. Through the simple relay operation, the ac–dc converter switches the operations according to the grid phase. By applying the active power decoupling technique to reduce the used capacitance and substitute to film capacitor, it solves the problems of lifespan and stability caused by using electrolytic capacitors. The ac–dc converter variably control the dc link voltage to maximize the battery voltage range of the DCX region with good efficiency characteristics for the dc–dc converter. In addition, the CLLC resonant converter performs the seamless control combining with frequency control and phase-shift control by using only one PI controller. A 17.6/22 kW(1Ø/3Ø), 2.18 kW/L prototype is implemented to validate the proposed concept and demonstrated 95.77% and 94.98% peak efficiency for three- and single-phase, respectively.