PWM Technique for Non-Isolated Three-phase Soft-Switching Buck-boost PFC Converter

The buck-boost power factor corrected (PFC) converter has the wide range of the dc output voltage. A new non-isolated three-phase hard-switching buck-boost PFC converter and a new non-isolated three-phase soft-switching buck-boost PFC converter are proposed. Their structures are very compact and the low cost is achieved by removing the three-phase transformer. They are operated in the discontinuous current mode (DCM) and controlled by a new control method to achieve the high power factor. The new control method based on the PWM technique is presented in this paper.