Electric Vehicle Auxiliary Power Module Using GaN HEMTs

The auxiliary power module (APM) of electric vehicles (EV s) provides power for the 12 V battery system. Since the EV s are becoming more intelligent and versatile, the increasing load requires a compact size, lightweight, and high-efficiency APM. Gallium nitride (GaN), as a kind of wide bandgap power device, has the advantages of low loss, zero reverse recovery current, etc. The aforementioned features enable GaN HEMTs to be a good solution for next-generation EV auxiliary power modules. This paper aims to design and optimize a 2.5 kW, 400/12 V APM using GaN HEMTs. It employs a dual active bridge DC-DC converter as the topology. The hardware and the magnetic components are optimized via theoretical analysis and simulation. Due to the large output current., extended phase-shift control is employed to minimize the current stress on the power devices. The experimental results have validated the theoretical analysis and the hardware optimization.