IEEE Workshop on Wide Bandgap Power Devices and Applications in Asia (WiPDA Asia 2018)

330 / 2017-12-08 21:44:39

Analytical Switching Loss Model of Cascode GaN HEMTs Based Totem-Pole PFC Converters Considering Stray Inductances

Plenary track > Very high efficiency and compact converters

A new analytical switching loss model is presented in this study to predict power losses and waveforms of high-voltage cascode GaN high electron mobility transistors (HEMTs) during half-bridge hard-switching operation. This model depends on datasheet parameters of the devices, as well as the stray inductances obtained from the printed circuit board. It is important to note that it clarifies the switching process and waveforms, providing information about how these stray inductances determine switching loss and hence the final converter efficiency. Moreover, the dynamic effects caused by the gate ferrite bead in package and the nonlinear capacitances is investigated in detail. Finally, the accuracy of the model is validated with experiment results, and a peak efficiency of 99.26% is achieved for a 3.6 kW single phase CCM Totem-Pole PFC AC/DC converter switching at 50 kHz based on 650V cascode GaN HEMTs.