A Smart and Highly Compact Power Electronics Box to Provide Universal Charging Technologies (OBC, Wireless and DC Fast Charging) along with DCDC


To use 650V GaN devices when receiving 480VAC input and outputting 800VDC, we need three-level PFC and DCDC topology. Furthermore, this project is a bold attempt to make the charger more versatile by including DCDC, OBC and WPT into one box. This requires novel magnetic coil design as well.


EV charger station example

The project described will develop a highly integrated power electronics box embracing multiple functions for electric vehicles (EVs), e.g., three-phase 22kW charging, single-phase 6.6kW charging, wireless charging, fast charging and 2.5kW (scalable to higher power for future autonomous and connected vehicles, say 3.7kW) DCDC conversion from HV battery (up to 800V) to 12V. Key technological innovation includes 1) Co-sharing the legs between accessory power module (APM) and the on-board charger (OBC) to reduce the usage of power switches, yielding lower cost, 2) Advanced control strategy to secure soft switching for DC-DC stage yielding high efficiency; 3) novel design of the magnetic coupler; and 4) Advanced control algorithms to realize V2G, G2V and V2L (vehicle-to-load).

How WBG Can Help

The success of this project demonstrates the application of LV GaN in HV areas, which eventually yields to cost and size reduction. Lower loss compared to Si based OBC makes the air cooling possible, which further reduces the cost of the mechanical and heatsink.

Personnel Involved

  • Liyan Zhu
  • Ziwei Liang
  • Yue Sun
  • Ruiyang Qin
  • Jie Li