Simple controller for single-phase power factor correction rectifier

This study proposes a simple low-cost modulating duty cycle analogue controller to reduce line frequency harmonics for high power factor boost rectifier. The proposed method eliminates the need for current sensing, and simultaneously offers the performance results comparable to those of continuous conduction mode (CCM). This scheme also maintains the simplicity comparable to that of discontinuous conduction mode (DCM). Only the output voltage and the rectified input voltage are monitored to vary the duty cycle of the boost switch within a line cycle so that the third-order harmonic, which is the lowest order harmonic of the input current, is reduced. As a result, the total harmonic distortion (THD) of the line current and thus the input power factor is improved. Moreover, the rectifier shows a good transient performance where the converter´s output voltage overshoots during input voltage/load transients is reduced. The proposed method is developed for constant switching frequency boost rectifier. Simulation and experimental results are presented to verify the effectiveness of the proposed control method.