A hardware-efficient programmable two-band controller for PFC rectifiers with ripple cancellation circuits

This paper introduces a hardware-efficient controller for rectifiers with power factor correction (PFC) that feature circuits for cancellation of the output voltage ripple at two times the line frequency. It provides simultaneous and independent regulation of the ripple amplitudes and dc voltage values for both the PFC stage and the cancellation circuit, allowing for the tradeoff management between the overall system volume and its efficiency. Unlike previous solutions, the controller does not require costly components for obtaining information about the output current, converter parameters, or phase and frequency of the voltage ripple. These advantages are obtained through the hardware sharing and use of a novel two-band compensator. The effectiveness of the controller is demonstrated on a 45 W programmable-output flyback based PFC rectifier prototype with a buck-boost based ripple cancellation circuit. The results demonstrated achieves a 1% ripple for the full range of operating conditions with maximum of 90% ripple reduction while utilizing a 500uF output capacitor for PFC, providing high power factor and low harmonic distortion.