A Power Factor Correction (PFC) stage is often used after the rectifier stage to improve the input power quality, Power Factor (PF) and the Total Harmonic Distortion (THD) of the Input Current. Active PFC in the form of an AC-DC converter stage can be used, but Passive PFC circuits are often preferred as they reduce cost and design complexity. A Passive Valley-Fill (VF) PFC is described in this presentation. The challenges of using the VF-PFC for motor drives are discussed along with a proposed approach to mitigate drawbacks in order to achieve excellent performance with an efficient, cost-effective design.
.jpg "Juan Paolo Quismundo, MSc photo")