The Research Of Low Current Startup Interleaved Boost PFC Converter And Its Control Technology

During the operation of power electronic equipment,it will bring harmonic interference to the power grid and affect the stability and reliability of the power system.Power Factor Correction(PFC)technology can effectively solve the problem of harmonic pollution and improve the power factor of equipment.The Boost circuit is often used as a PFC converter topology because of its structure,simple driving circuit,and small input current ripple.The use of multiple Boost PFC staggered parallel methods can not only improve the power level and reduce the current stress of power devices,but also further reduce the input and the output current ripple,reducing the size of the filter and capacitor,has obvious advantages in high-power applications.However,the precharging of the output capacitor during PFC startup will cause a large inrush current,increase the power device current stress,and reduce the service life of the device.The commonly used surge current suppression circuit is large in size and low in reliability.Based on the research of the working principle and characteristics of the staggered parallel Boost PFC converter,this paper discusses the implementation of the surge current suppression circuit,and proposes a low current start staggered parallel Boost PFC converter.First,the classification and development trends of PFC technology are described.The Boost PFC topology and operating mode are introduced.The main circuit parameters and loss distribution are calculated.The control methods and inductor current synthesis methods for different operating modes are analyzed.The Boost PFC in CCM mode is small.Signal modeling and design compensation circuit.Secondly,a thyristor inrush current suppression circuit is designed,which effectively reduces the startup surge current of Boost PFC and the current stress of power devices.The circuit structure and working principle of the circuit are introduced in detail,and the low inrush current and constant wave are compared and studied.The implementation method and effect of inrush current.In addition,based on the relationship between the established start-up time and the inrush current,an optimal inrush current suppression scheme is obtained.While suppressing the inrush current,a good dynamic response can be obtained.Finally,TI 's chip UCC28070 was used to design the staggered and parallel Boost PFC circuit,and based on the MicroChip PIC16F1704 control chip,the surge current suppression circuit of Boost PFC was designed.A 1kW experimental prototype was built(input 85-265 VAC,output 400VDC).In order to ensure the expansibility of the PFC circuit and meet the development needs of industrialized module power,the experimental prototype was designed according to the module power index,and step-by-step debugging was used to obtain the experimental waveforms that reflected the working status,which verified the correctness and validity of the theoretical analysis.