Virtual infinite capacitor applied to DC-link voltage filtering for electric vehicle chargers

Abstract

The virtual infinite capacitor (VIC) is a nonlinear active capacitor for DC voltage filtering. It can replace large and unreliable electrolytic capacitors and is intended for DC systems where random fluctuations of the DC bus voltage may occur. In this paper, we investigate the use of a VIC for stabilizing the DC bus voltage in an electric vehicle (EV) charger. In order to solve the intrinsic problem of the second harmonic ripple power in a single-phase AC/DC converter, a plug-and-play VIC is used to replace the bulky DC-link capacitor for voltage filtering.