【作者】 罗春槐；

【导师】 唐小琦；

【作者基本信息】 华中科技大学 ， 机械电子工程， 2007， 硕士

【摘要】 AC/DC变换器是电器装置中最常用的一种变换器,为了减小其对电网的污染,提高输入功率因数,需要采用功率因数校正(PFC)技术。目前,单相功率因数校正技术已经成熟,但是三相功率因数校正技术仍处于研发阶段。采用Boost型电路拓扑的有源PFC技术由于具有总谐波失真(THD)小,功率因数接近1的优点而得到广泛应用。但是,其应用也受到成本、开关应力等因素的影响,需要进一步优化。本文在单相PFC技术控制模型的基础上研究了三相单开关PFC技术,这种控制方法优势在于控制简单实用,成本低,可以较好地实现电路功率因数校正功能;同时还研究了一种新颖的三相三电平功率因数校正电路,这种电路的优势在于功率开关管两端承受的电压应力为直流母线电压的一半,便于功率开关的选取,可以有效降低开关损耗。本课题的研究层次是:首先研究了PFC技术的实现原理,并研究了单相单开关PFC的控制方法,开发了试验样机,通过实验验证了其控制效果;其次,通过建立三相单开关PFC电路的单相等效控制模型,分析并确定各个参数关系,提出了一套实用的数字控制方案,通过实验验证了这种控制模型的有效性;然后,针对单个开关承受应力大的情况,研究了三电平三开关PFC技术,并通过数学分析建模,设计单周期控制方案,通过计算机仿真验证了这种方案的有效性;最后,对本课题研究作了总结和展望。更多还原

【Abstract】 AC/DC converter is a most widely used converter in electronic devices. In order to reduce the harmonic pollution of power supply and improve the power factor, more power factor correction technology is used.At present, the single-phase PFC is already developed, but the three-phase PFC is still in the stage of developing. The PFC converter based on the boost topology is being widely used for the advantage that input current total harmonic distortion is low and it makes input end power factor of the whole circuit into unity power factor closely. But the high DC bus voltage stress is an important issue for using and it needs further research.This thesis presents a new control model of three-phase power factor correction circuit, which based on the model of single-phase and has an advantage of low cost and high performance. Further more, this thesis presents a novel three-level three-phase single stage power factor correction circuit. The structure of the circuit reduces the voltage stress across the power switches to 50% of the bus voltage. It’s easy for us to choose the switching devices.Firstly, a novel control principle is presented after the research of PFC method, and the good effect of the principle is verified with the experiment. Secondly, an equivalent control model of three-phase is built, the parameters are analyzed one by one, a new three-phase power-factor correction scheme using digital control is designed and has a good effect in the experiment. Then, a circuit of three-level three-phase single stage power factor correction is researched. Its effect is verified through computer simulation. Finally, a summary of this thesis is provided, and some problems are discussed which point out the future study field.更多还原