A simple and effective method to alleviate the rectifier reverse-recovery problem in continuous-current-mode boost converters

Rectifier reverse-recovery problems cause a significant efficiency reductio n as well as severe electromagnetic interference (EMI) in continuous-curren t-mode (CCM) boost converters. To alleviate these problems, this paper pres ents a simple and effective solution that involves shifting the original re ctifier current to a new branch, which consists of a rectifier and a couple d winding of the boost inductor. When the active switch turns on, the curre nt through the original boost rectifier is zero and the current decrease ra te di/dt in the new branch is controlled by the leakage inductor. Based on the operation analysis, design issues to guarantee complete current shift a re also addressed. Applying the proposed concept to a 500 W CCM dc/dc boost converter and a 500 W CCM power factor correction (PFC) boost converter wi th universal-line input generates a 2% efficiency improvement. The same con cept can be easily extended to other basic dc/dc and CCM PFC converters.