GaN-based High-Frequency, High-Power-Density, 2-in-1 Bi-directional OBC Design for EV Applications

Inhalt:
Product design based on GaN power ICs can improve the switching frequency, reduce the volume of passive devices, and further optimize the product power density and cost. However, due to the small die size and fast switching characteristics of GaN devices, a new series of challenges to heat dissipation design, drive design and magnetic component design may occur. Based on an integrated "2-in-1" design of bi-directional 6.6 kW on-board charger (OBC) with 3.0 kW low-voltage (LV) DC-DC converter, this paper proposes an efficient heat-dissipation technology using Navitas integrated-drive GaN power ICs. The switching frequency of CCM-PFC is set as 100 kHz, and the switching frequency of soft-switched bi-directional boost series-resonant converter (boost-SRC) is above 400 kHz, with maximum operating frequency of 800 kHz. The volumes of PFC inductance and transformer are reduced significantly, with overall power density up to 3.9 kW/L.