A Novel Method for Current Ripple Control Used in PFC Converter

Due to the large current ripple of PFC converter used digital hysteresis control, this paper proposes a novel control arithmetic for current ripple minimum. Calculating the slope of current raise and fall, duty cycle can be calculated realtime with help of the current sampling value. In addition, considering the characteristic of digital sampling, this paper proposes a method that the point of current sampling during every switching period can be adjusted based on duty cycle, and it can ensure the current precision during sampling process. Experimental results prove that this control arithmetic can decrease the current ripple with fast response used digital hysteresis control.