Integrated High- and Low-Frequency Current Ripple Suppressions in a Single-Phase Onboard Charger for EVs

Abstract

Current ripples produced in single-phase onboard charging systems of electric vehicles (EVs) impact the lifetime of their batteries. In this article, an isolated multifunctional charger topology is proposed. The charging system can be used to charge the auxiliary batteries or serve as an active filter (AF) for the power battery charger. By time-sharing multiplexing it, the high-frequency (HF) and low-frequency (LF/second harmonic) current ripple can be suppressed in driving and parking charging modes, respectively. The proposed topology can also achieve zero voltage switching for all power switches under a full-load range in the driving charging mode. In addition, the integration and the power density of the charging system can be improved due to the reconstruction of the capacitive energy storage AF in the parking charging mode. Finally, a 400-W experimental prototype is developed and the experimental results are presented to validate the performance and feasibility of the proposed topology.