The Research Of Interleavedhigh-power PFC Converter

With the rapid development of power electronics technology,some power electronic devices have been widely used,for example,AC-DC converters are widely used in household appliances,uninterruptible power supplies,energy-saving lamps,communication power supply and other occasions,this leads to a more serious problem of harmonic pollution,a serious threat to the health of the grid.In order to solve the problem of the harmonic pollution effectively,the power factor correction(PFC)technology is introduced.This technology can effectively improve the power factor in the switching power supply,and reduce the harmonic problem of input current.With the continuous improvement of power level,the traditional single-phase boost PFC converter can not be used in the larger power occasions,because of its device selection,size,efficiency of the whole machine and other factors,so the demand for high-power PFC converters becomes more and more urgent.By using interleaved technology in boost PFC,the switch's interleaved conduction can decrease the input current ripple and current stress of power switch effectively,and the efficiency of the converter can be improved,this converter is very suitable for the high power applications.Therefore,this article will mainly study the interleaved high-power PFC converter.First of all,this paper gives an introduction of the background and the development of power factor correction technology,and describes the classification and topology of this technology.Then,this paper analyzes the working state and circuit characteristics of the interleaved boost PFC in Continuous Current Mode(CCM),and the control strategies of boost PFC are compared.According to the advantages of average current control,this paper uses the double closed-loop control method,and introduces its working principle in detail,then construct a simulation circuit.Finally,based on UCC28070 the analog control chip of TI,the experimental circuit of interleaved boost PFC is designed by designing the parameters of main circuit,control circuit and auxiliary power supply.The experimental waveforms of converter are obtained through step-by-step strategy.Simulation and experimental results show that the power factor correction effect ofthe interleaved PFC circuit is good,and this circuit can suppress the input current ripple well,thus confirming the theoretical analysis is correct.