A device suitability analysis is performed herein by comparing the performance of a silicon carbide (SiC) metal-oxide-semiconductor-field-effect transistor (MOSFET) and a gallium nitride (GaN) high-electron mobility transistor (HEMT), which are wide-bandgap (WBG) power semiconductor devices in induction heating (IH) systems. The WBG device presents advantages such as high-speed switching owing to its excellent physical properties, and when it is applied to the IH system, a high output power can be achieved through high-frequency driving. To exploit these advantages effectively, a suitability analysis comparing SiC and GaN with IH systems is required. In this study, SiC MOSFET and GaN HEMT are applied to the general half-bridge series resonant converter topology, and comparisons of the conduction loss, switching loss, reverse conduction loss, and thermal performance considering the characteristics of the device and the system conditions are performed. Accordingly, the device suitability in an IH system is analyzed. To verify the device conformance analysis, a resonant converter prototype with SiC and GaN rated at 650 V is constructed. The analysis is verified by an experimental comparison of power loss and thermal performance.

Because SiC MOSFET-based zero-voltage switching (ZVS) power converter circuits provide high-speed switching, high power density and high efficiency can be achieved. However, an undesired negative spike is formed at the gate-source voltage owing to the crosstalk phenomenon in leg structures, such as half-bridge switch configurations, during high-speed switching. Additionally, ringing voltage occurs owing to resonance between the snubber capacitor and the common source inductance of the SiC MOSFET. Because SiC MOSFETs have a lower gate voltage rating than conventional Si devices, it is essential to reduce the negative spike and ringing voltages to ensure reliability. In this paper, the gate driver circuit is proposed for reducing the negative spike and ringing voltages of the gate-source in ZVS circuits. Because the proposed gate driver circuit provides an effective impedance path for each section through an active switch, a stable driving voltage range of the gate-source can be achieved. To verify the proposed gate driver circuit, an accurate simulation model of the 3-pin SiC MOSFET package is proposed, and the validity of the proposed model is verified through comparison of the simulated waveforms with experimental waveforms. The performance of the proposed gate driver circuit is verified through PSpice simulation.