A High Power-Density SiC-based TP PFC with a High Frequency Ripple Cancellation Leg

Inhalt:
This paper introduces a novel ripple cancellation method by incorporating a high-frequency ripple cancellation leg comprising GaN FETs, connected in an interleaved manner with the SiC-based low-frequency half-bridge. The primary aim of the high-frequency leg is to generate an equal and opposite ripple current to counteract the low-frequency inductor current ripple, effectively canceling it out. This results in the elimination of low-frequency ripple at the input, leaving only the very high-frequency ripple current. Consequently, the differential-mode (DM) filter is tasked with filtering this high-frequency ripple current. The proposed approach streamlines the EMI filter to a single stage and offers the advantage of optimizing the design of the PFC inductor without the need to consider any consequences related to differential-mode noise; thus providing a very high-power density design for high power applications.