Feed-Forward Slope Compensated PFC for Chaos Control

Abstract

Based on the dual-loop control peak current mode power factor correction (PFC) converter, a feed-forward slope compensation method is proposed, which could regulate the compensated slope real-time and suppress the loop perturbation, thus controlling chaos of the system for better stability. A dual-loop Boost PFC model with the feed-forward slope compensation is built to analyze the nonlinear phenomena in system, and the corresponding circuit structure is presented. The chaos control ability of the feed-forward slope compensation is studied theoretically, and the relation of compensated slope and feed-forward signal is deduced, as well as slope stability conditions. The simulation and measured results show that this method could e®ectively suppress system bifurcation and chaos phenomena, and improve the system working range and dynamic response speed, and eliminate the in°uence on system stability for without compensated, under compensated, and over compensated.input disturbance-rejection, as well as the fast response speed. So it is necessary and signi¯cant to study the dual-loop PFC converter to control its nonlinear phenomena. However, the nonlinear behaviors are di±cult to control for uncertain, which probably result in unpredictable system working state, and give rise to a high total harmonic distortion (THD) and poor power factor (PF). Now the proposed system chaos control methods include parameter perturbation control, feedback control, pole control, and so on. Although most are easy to realize, their complex control modes often restrict the application. The slope compensation control provides an e®ective solution. The reasonable compensation network could simplify the system to be¯rst-order, thus ameliorating the bifurcation and chaos phenomena. But the¯xed compensated slope existing probably causes over compensation or under compensation, and¯nally reduces the applicable working voltage range and transient response speed. To make up for the drawbacks above, a feedforward signal is introduced in the slope compensation, which regulates the loop gain according to real-time disturbance, and reduces the bandwidth requirements of feedback control loop, thereby decreasing or eliminating the noise interference,¯nally inhibiting chaos.Based on the dual-loop peak current mode Boost PFC, a feed-forward slope compensation circuit is proposed to control chaos, with the system model. The simulation and measured results verify the validity and feasibility of the proposed circuit. The feed-forward slope compensation provides PFC converter an e®ective way to control nonlinear phenomena and improve stability, as well as better working range and dynamic response.The rest of this paper is organized as follows. In Sec. 2, PFC model in dual-loop peak current mode with the slope compensation is presented. In Sec. 3, the feedforward slope compensation control is proposed, with the actual circuit. In Sec. 4, the simulation and measured results are performed to verify the e®ectiveness of this work. The conclusions and discussion a...