A Comparative Analysis of GaN, SiC, and Si Transistors in kW-range Synchronous Converters

In this paper, the power-frequency capabilities of different semiconductor technologies are explored. The maximum achievable output power for different switching frequencies of GaN-, SiC-, and Si-based converters are established and compared, providing insights into the limits of each semiconductor technology in kW - range applications. In addressing the posed objective, this paper explains modelling techniques that can be universally applied to accurately approximate waveforms and calculate losses for converters under both hard- and soft-switching conditions. These models form a theoretical framework to analyze the power-frequency design-space in power electronic systems. Based on the models developed and results obtained herewith, it can be concluded that GaN switches stand out in terms of power-frequency capabilities, enabling MHz-level operation of a single half-bridge at multi-kW power levels, something which is not possible using SiC or Si under similar system parameters. The models and methods presented in this paper can be applied to various semiconductor switches and converter topologies, providing a foundation for other comparative analyses as well.