GaN HEMT Outperforms Silicon in Low Frequency Applications

For some efficiency-oriented applications such as traction inverter, energy storage systems and home appliances, the switching frequencies are usually much lower than the capability of wide-bandgap-devices. The potential of GaN HEMT in such applications will be investigated in this paper. To maximize the energy saving and reduce battery cost (if applicable), the weighted-average efficiency is always taken into considerations. According to their operating mission profiles, these systems are operating under 30% of load or less most of the time. The experimental data shows that in this case, the GaN device has both lower switching and conduction loss versus the silicon component so that the advantages of GaN HEMTs are fully utilized with the switching frequency limited to 50kHz. Examples of a GaN-based air conditioner, refrigerator, traction inverter and energy storage system are presented.