High Efficiency GaN-based Non-isolated Electric Vehicle On-board Charger with Active Filtering

Electric vehicle (EV) on-board chargers (OBCs) should have high efficiency and high power density. Since the transformers in isolated OBCs generally lower both of these metrics, this paper proposes a novel non-isolated OBC with very high efficiency and a low component count. Active filtering is proposed to allow the use of smaller dc-link film capacitors to further improve power density. This paper discusses the design process for the dc-link capacitors and the operation of the active filtering control. Simulation results show that for level 2 charging, the proposed converter has a peak efficiency of 98.8% and efficiency of 98.6% at full 3.3 kW load. Furthermore, the simulation results confirm acceptable THD and power factor performance of the proposed topology.