Patent ID: 11068005

Abstract:
A power factor correcting method for correcting a power factor in an alternating current power supply includes detecting zero-crossing points of an input voltage VAC of the AC power supply to obtain a period T of the input voltage VAC; generating a half-wave symmetric periodic function f(t) by using the period T; implementing a recursive low-pass filter y(t) by using the half-wave symmetric periodic function f(t), so that an output of the recursive low-pass filter y(t) matches a target reactive current Ixcap(t) flowing through an X-capacitor; generating a reference current I′ref(t) for correcting the power factor by using a given reference current Iref(t) and the recursive low-pass filter y(t); and correcting the power factor by using the reference current I′ref(t). Accordingly, the reactive current of the EMI capacitor can be compensated in a high code efficiency manner.