SiC Power Devices in a Soft Switching Converter, Including Aspects on Packaging
In a recent paper, , frequency dependent IGBT losses are evaluated. Fig 2 shows the on-state voltage of an IGBT when conducting a sinusoidal current at different frequencies. At the higher frequency (30 kHz, Tr4) the increase of conduction losses is evident.
Power switches made from SIC show excellent properties enabling; low conduction losses, high frequency operation and an ability to operate at high die temperatures . Fig 3 (a) shows the on-state voltage of an unipolar SIC switch while Fig 3(b) shows the on-state voltage of a bipolar switch. Measurements have been performed up to 200 kHz without showing any high-frequency effects.
High voltage SiC PiN diodes can replace several series connected Si diodes due to the higher critical field strength in SiC. This enables substantially reduced conduction losses in the output rectifier. In Fig 4 on-state voltages of 10 kV SiC and Si-diodes are shown, indicating a 50% reduction of losses.
 V. Vlatkovic, M. J. Schutten, and R. L. Steigerwald, “Auxiliary Series Resonant Converter: a New Converter for High-Voltage, High-Power Applications,” in Proc. of PESC -96, 1996.
 P. Ranstad, and H-P. Nee, “On dynamic effects influencing IGBT losses in soft switching converters,” IEEE Transactions on Power Electronics, vol. 26, No. 6, December 2010.