The Research On Active Power Factor Correction Technology With Average Current Mode

Switching converter is widely used in the power field. However, the nonlinear characteristics of switching devices often lead to the input current distortion. Contains a lot of distortion of input current harmonics, power will cause serious pollution. Active Power Factor Correction technology not only improves the power factor by reducing input current harmonics, but also greatly improves the efficient use of energy and creates huge economic benefits by reducing harmonics interference on the power and communications equipment. The Power factor correction technology is significant for the development of switching converters.This paper introduced the definition of power factor correction and development first, and analyzed in detail the active power factor correction circuit how to work. The topology and control methods are analyzed. Three common APFC circuit topologies (Buck, Buck-Boost and Boost) of their main advantages, disadvantages, similarities and differences are studied. Each control method of power factor correction circuit is compared in the discontinuous and continuous inductor current state. The Boost PFC is studied as the main research object in this paper because of its low input current ripple and high power factor with universal input voltage range and frequency.The multiplier is commonly used to realize power factor correction in average current mode with voltage loop and current loop. Based on the traditional average current mode, a new control method using the feed-forward signal of input voltage is added. The introduction of feed-forward circuit not only makes the input power remain constant, but also enhances the rapid response capability of the system greatly. The loop gain of control circuit will not be affected by input voltage. It is easy to work with universal input voltage range and remain good dynamic response and load regulation characteristics. With the analysis of each state of APFC circuit, we can build the MATLAB model and analyze the simulation results based on the average current control method to research its dynamic response ability in the condition of input voltage and load change.Finally, the APFC circuit is designed with the equivalent circuit model based on PSIM. The simulation analysis showed that the APFC controller can effectively reduce the input current distortion to achieve power factor correction. Meanwhile, the simulation experiment research is carried out with different inductance values, different input voltage conditions and different filter capacitor ESR values to study the characteristics of the system.