新型单周控制的单相功率因数校正器

Novel single-phase PFC corrector with one cycle control

提出了一种基于单周期控制的单相通用PWM(Pulse Width Modulation,脉冲宽度调制)调制器,并将其应用于单相Boost功率因数校正(PFC,Power Factor Correction)电路中,分析了单周期控制的单相Boost PFC电路的控制规律.针对流行的单周期控制的单相Boost PFC电路,提出了一种改进方案,该方案增加了一个电阻补偿网络和一个加法器,主电路电感修改为带中心抽头的三点式电感,其它基本参数和流行的单周期控制电路相同,这样就消除了由于电感电流纹波造成的畸变,同时在一定程度上减小了由于电流断续模式(DCM,Discontinuous Current Mode)引入的畸变,提高了功率因数校正主电路的可靠性,最后给出了系统改进后的试验验证,试验结果说明改进后的PFC电路可以大大提高系统的功率因数,功率因数可达0.994.

A new general PWM modulator for single-phase PFC corrector with one cycle control is proposed in deducing the general single-phase PFC governing equation. The PWM modulator is used in single-phase Boost topology. The single-phase, Boost PFC corrector＇ s control law is deduced. In view of popular single-phase Boost PFC corrector based on one cycle control, an improved single-phase power factor corrector is proposed. A resistance compensating network and an accumulator are added in the improved corrector and its main circuit inductance is revised for the center-tapped inductance. Other basic parameters are the same as the popular sin- gle-phase PFC corrector. Thus the inductance current ripple distortion is eliminated. The distortion introduced by the DCM is reduced to a certain degree, The reliability of the PFC corrector is also enhanced. Finally experimental results of the improved PFC corrector are given. It shows that the improved corrector can greatly enhance the system＇ s power factor. Its power factor can reach 0. 994.