A ripple-free input current PFC using power semiconductor filter

A new ripple-free input current power factor corrector (PFC) using boost dc-dc converter is presented. By applying a concept called “Power Semiconductor Filter (PSF)” for input filtering, the input current ripple of the PFC can be reduced by using a semiconductor device. The requirement of the differential-mode filter for the entire system can be greatly reduced. The methodology of the PSF is based on using a series-pass device (SPD) to control the input current waveform of the converter. The operating point of the SPD is regulated at the boundary between the active and saturation regions by controlling the input impedance of the boost converter, so that the power dissipation of the SPD is minimized. A 150W, 90-240Vac prototype has been built and evaluated. The boost converter is operated in the discontinuous conduction mode (DCM). Investigations reveal that the PSF allows a substantial reduction in the physical size and provides a high power factor and a low total harmonic distortion of line current at both full load and light load. Modeling, design, and analysis of the entire system will be presented.