The power factor correction techniques have received great attention. A discontinuous conduction mode (DCM) converter eliminates the complicated circuit control requirement, reduces the number of components, and reduces the filter reactive components size. The disadvantage of the DCM converter is to increase the voltage and current stresses of the switching devices because the device must be switched off at a maximum inductor current.
The buck-type PFC-DCM converter has several advantages such as a restriction of rush current, easy protection of short circuit and low rating voltage of devices. In general, the output do voltage of the buck-type PFC-DCM converter is limited up to one tenth of the input ac voltage because of a distortion of the input current waveform at higher output do voltage.
A new soft-switching buck-type PFC-DCM converter is proposed. The proposed circuit is able to achieve the zero voltage switching (ZVS) at the maximum current. Therefore, the new soft-switching buck-type PFC-DCM converter decreases the voltage and current stresses of the switching devices. In this circuit, resonant capacitor, which is used for soft-switching operation, is utilized for the improvement of an input current waveform.
