Soft Switching Controlled AlGaN Based Power Transistors for Induction Heating Applications

This paper reports on our first and series trial to apply the AlGaN heterojunction field effect transistors (HFETs) for in substitution for Si transistors in the induction heating (IH) applications. The on-resistance of the 800 V/50 A AlGaN HFET was 0.11 ohm, and the turn-on and turn-off times were less than 20 ns, respectively, which are lower than that of conventional Si based metal-oxide-semiconductor field effect transitors (MOSFETs). The input capacitance of the AlGaN HFET of up to 350 V was one digit smaller than that of the conventional Si MOSFETs. We fabricated the IH system with a soft switching circuit driven by the AlGaN HFETs. We realized the operation of this IH cookers at an operation voltage of 280 V and current of 8 A at a frequency of 29.6 kHz.