Application of Fractional Order PI Control in Single-phase Active Power Factor Corrector

Single-phase active power factor corrector (APFC) can eliminate harmonic current pollution to the grid harmonic current. APFC uses a double closed-loop control structure with a voltage outer loop and a current inner loop. Although this control method is very simple, the dynamic response characteristics need to be improved. After analyzing the definition of fractional PID and the design process of fractional PI controller parameter, the fractional-order operators is calculated by using the Oustaloup approximation algorithm, so that a double closed-loop variable coefficient PI controller with a voltage outer loop and a current inner loop are designed in APFC to adopt fractional PI control. The pure resistive load is taken as an example for simulation analysis and compared with the three conditions of the traditional PI controller. The results demonstrate that the APFC can obtain good dynamic and static characteristics by adopting double closed-loop fractional PI control with proper order.