The APFC system based on an improved duty cycle control algorithm

Aiming at the problem that the digital control Power Factor Correction technology has some deficiencies in the dynamic responses and stability, a new Active Power Factor Correction (APFC) system based on an improved duty cycle control algorithm is designed in this paper. In this algorithm, when the load and the input voltage go step change, the output voltage ripple and the input voltage feed-forward are introduced to compensate the duty cycle during each switch cycle to ensure the input current an undistorted sinusoid. So it guarantees the high speed of dynamic response and the stability of the APFC system. Also the efficiency and reliability of the APFC system are improved by applying minimal voltage active-clamp soft-switching technology, which can inhibit the reverse recovery of diodes effectively.