Study On Single Phase Active Power Factor Correction Converter Of Predictive Averaged Current Mode Control

A great mount of power harmonics is produced along with the development of power electronics and the wide application of power electronics equipments. Harmonic issue has become a focus of concern in the field of electrical engineering problems. Active power factor correction(APFC)is regarded as an effective way to correct power harmonics and to improve power factor and has been paid much attention by the academic community. It develops very quickly and be applied more widely. The two-stage APFC on the literature generally refers to the pre-regulator and the post-class level of the DC\DC power conversion of the Boost APFC. There are two main research focuses on the Boost APFC: One is the power level further improved; the other is to simplifying the control circuit.In this dissertation, the control strategy of the pre-regulator of the two-stage Boost APFC is the main content. The traditional average current control, hysteretic current control and peak current control need inner current regulator, detection of the rectified input voltage and multiplier, which make more complex and higher cost of the control circuit. Furthermore, the nonlinear distortion of the multiplier increases the input current harmonic content. Therefore, make a search for the more simple control strategy , reduce active power factor correction costs, reduce THD and EMI, reduce stress of the switching and improve efficiency become the trends of APFC. To aim at the development trend of the control strategy of APFC, this dissertation presented a new control strategy of APFC-predictive averaged current mode control.Firstly, based on referring to a lot of literatures, taking single-phase APFC systems as an object, this dissertation introduces the classification and their respective characteristics of the control strategy of APFC in common use at present.Secondly, based on the basic idea of predictive control and basic principle of the one cycle control, the Predictive Averaged Current Mode Control is expounded, its control equation is derived and analysis its stability.Finally, the single-phase Boost APFC system of the Predictive Averaged Current Mode Control is designed. Building the simulation model which accepted by the internal of Saber. And the simulation results are analyzed.Theoretical analysis and simulation analysis show that the single-phase Boost APFC of the Predictive Averaged Current Mode Control has a simple and anti-interference capability, fast response time, meet the wide range of input voltage and load advantages. The control strategy breaks through the need for the multiplier and the detection for input voltage. The concept of the strategy is direct and easy to control, provides a high performance and low-cost control strategy for APFC.