A High-Efficiency, High-Power-Density Integrated DC/DC with OBC Using SiC and GaN Devices for Electric Vehicles


The project is to provide automotive companies a high-efficiency and high-compactness integrated DC/DC with on-board charger (OBC), e.g., able to do three-phase on-board battery charging@22kW, or single-phase charging @ 19.2kW, and a 6kW-peak-power DC/DC conversion between the high-voltage battery (200~500VDC) and low-voltage battery (6~16VDC). Efficiency >96% is expected for both OBC and DC/DC. The charger and DC/DC will share what would be redundant circuitry in a non-integrated design to reduce the overall system cost and complexity.


UTK 400V/12V/6kW DCDC Converter using WBG Devices.

The final deliverable of this project is an integrated DCDC with OBC. The system will be designed to meet the OEM vehicle specifications and safety standards. More specifically, the team proposes two stage design. Phase 1: Literature review, simulation and comparison. At this stage, the team will process the "paper" design by investigating, simulating and comparing the various topology. This will help the UTK and company better understand the component selection, design limit and cost of various topology. The best topology will then be selected for Phase 2: Prototyping and testing, when the team will then design, prototype and test the circuit to validate the proposed topology.

How WBG Can Help

To provide EV companies a compact, light and efficient OBC+DCDC, >650V SiC/GaN devices will be used at the HV side and <100V GaN devices will likely be used at LV side. Such affordable and integrated approach is EV companies' favorite choice thereby expediting WBG application in automotive domain.

Personnel Involved

  • Changchieh Lo
  • Liyan Zhu