PERTURBATION ON-TIME (POT) CONTROL AND FREQUENCY SHIELDING CONTROL (FSC) IN SUPPRESSION OF THD OF POWER FACTOR CORRECTION (PFC) DESIGN

摘要

The power factor correction (PFC) controller with the improved total harmonic distortion (THD) technique is introduced in this paper. The THD is reduced by the perturbation on-time (POT) control technique to improve the performance of the PFC in the AC-DC converter. Simultaneously, the efficiency can be enhanced by the proposed Frequency Shielding Control (FSC) mechanism at low AC input voltage. The zero current detector (ZCD) is also used to detect the negative voltage and trigger the PWM signal. The test circuit fabricated in TSMC 800V UHV process can show the highly-integrated and high efficiency PFC controller. Experimental results demonstrate low THD of 8%, which results in high PF of 99%. High efficiency of 95% can be ensured at the output power of 90W.