Multi-level CHB rectifier with common-duty-ratio control suffers from low power factor in light-load condition, which related to small boost inductance and insufficient gain of current compensator at line-frequency. In order to solve this problem, a practical design method based on proportional resonant compensator is proposed, which can realize the optimization of power factor under light load. Finally, the effectiveness of the design method is verified by experiments, and the light-load power factor of CHB rectifier is increased to 0.95.
Analysis and Solution for Deficient Light-Load Power Factor in Multi-level Boost PFC with Common-Duty-Control. Wending Zhao