Research On High Power Factor Rectifier Based On Single-Phase CRM Interleaving Parallel

When boos t converter works in critical continuous conduction mode, the circuit possessed the advantages of ZCS and zero reverse recovery currents. But the input current contains a great component of current spikes and current ripples, which constraints this method from using in large capacity power converter. Interleaving means that all the drive signals operate under the same frequency while the phases of the drive signals are displaced. Interleaving can reduce current ripples and lower EMI level of the power system. The objectives of this thesis are to study and design the implement of interleaving boost PFC in critical mode and make the application of this circuit in a higher power capacity possible.Firstly, the paper summarizes the research background, the status of PFC technology and the characteristics of interleaved parallel. And the significance of the subject and research content are pointed out. The circuit uses a three-interleaving parallel CRM-Boost-PFC, which makes the synthesis input current continuous, reduces the current ripple and the stress of power components.In this thesis, the high power factor rectifier of CRM interleaved parallel uses master-slave control mode。The drive signal of master switch is introduced a interleaving control circuit, which produces drive signals of the slave switch, and makes the drive signals of master switch and slave switch be displaced byπ3 and 2π3 phase. According to the experimental requirement and the chip features, design on the unit is performed. first of all ,I calculate the main parameters of the circuit and I introduce the chip's working principle and how to select the external circuit parameters And then designed a simple control, fast response of the three staggered control circuit, this paper analyzes the working principle of the circuit described, and simulate the circuit. Finally,I do experiment on CRM-boost-PFC based on the FAN7529 chip control It is based on the control of FAN7529. And, the experiment is implemented on high power factor rectifier of single-phase CRM interleaving parallel. A 500W experimental prototype is also built up. The prototype eventually realizes that the THD is less than 8%, achieving the effect of a good power factor correction.