Design And Implementation Of Three-way Interleaved Parallel PFC Circuit

In the fast-developing information age,switching power supply plays an indispensable role.It has the characteristics of light weight,small power consumption,low power consumption and high conversion efficiency.However,when it is popularized,not only the power factor is low,but also The pollution to the power grid and peripheral equipment is very serious,which has aroused people's attention.The power factor correction technology(referred to as PFC technology)is applied to the switching power supply to solve the drawback of harmonic pollution.Since then,PFC technology has been widely used in the field of small power switching power supplies.This paper first explains the research background and prospects of PFC technology,introduces the development process of PFC technology from passive to active,and summarizes the four directions of PFC technology research and development,namely topology,control method,power device and new application of technology.In this paper,a three-way interleaved PFC circuit is applied to the switching power supply by interleaving three Buck-Boost converters in parallel,and the digital single-cycle algorithm is used to realize the control of the circuit.Then the paper studies and analyzes the PFC technology,including the principle of PFC technology,the common converter and control method of PFC circuit.At the same time of analysis,the advantages and disadvantages of typical converters and control methods are compared.Then the main circuit designed in this paper is analyzed and explained.Firstly,the working principle of the main circuit and eight working states are analyzed.Then,the appropriate duty cycle range is selected by analyzing the inductor current.Then the principle and application of the single-cycle control method are introduced.Finally analyzed the working principle and working state of the single-cycle control Buck-Boost converter.Then from the perspective of hardware and software,the overall design of the PFC circuit system studied in this paper is expounded.The hardware design is divided into main circuit design and control circuit design.The software design is based on the Keil MDK software platform,which uses the STM32F427 chip to implement digital single-cycle control of the circuit system.Finally,based on the design of this paper,the prototype is made,and the prototype is tested and debugged.The auxiliary circuit is tested first to ensure the normal operation of the whole circuit system.Then the performance of the whole circuit system is tested and the test results are analyzed.The three-way interleaved parallel PFC circuit designed in this paper can not only solve the harmonic pollution problem of the switching power supply,but also realize the high efficiency of the switching power supply,and can also improve the current stress of the single-channel PFC circuit and the instability of the two-way interleaved PFC circuit system.Since the staggered parallel structure can make the parameters of each component used smaller and reduce the circuit cost,it has good practical value in the field of switching power supply.