【作者】 陈小丹；

【导师】 王松林；

【作者基本信息】 西安电子科技大学 ， 电路与系统， 2011， 硕士

【摘要】 发光二极管(LED)在照明应用中,因其具有发光效率高、寿命长、高亮度、节能、环保和坚固耐用等特点,正作为一种新型照明电源得到越来越广泛的应用。但是由于传统的开关电源LED驱动电路的广泛使用,给电力系统注入了越来越多的谐波,致使电网中的谐波污染日益严重,从而影响到电网供电质量和用户使用的安全性。有源功率因数校正(APFC)技术是提高电子产品的功率因数、减少电网污染和降低谐波干扰的有效方法。因此,在提倡“绿色电网”和“绿色照明”的今天,有源功率因数校正技术已成为研究的热点。本论文基于西安电子科技大学CAD研究所的科研项目“升压型有源功率因数校正控制器的研究”,设计了一款用于驱动LED的Boost型有源功率因数校正控制器XD8537。论文首先概述了功率因数校正技术的意义与发展现状;其次,详细分析了有源功率因数校正器的基本拓扑结构、控制方法和工作模式;然后在此基础上制定了XD8537的系统设计方案,完成了电路设计、功能和性能仿真验证。针对传统的电压模功率因数校正芯片瞬态响应慢的缺点,设计了一种新颖的高转换速率跨导误差放大器,能安全及时的处理电路故障、短路或负载的突变等情况;另外芯片采用了一种导通时间可调的控制方法,进一步优化了总谐波失真系数(THD)。本文设计的有源功率因数校正控制器XD8537采用0.4μm 40V BCD工艺,工作于临界导通模式,采用电压模控制,具有结构简单、体积小、功率因数高、THD小的特点。利用HSPICE仿真平台对芯片XD8537仿真验证可知,该芯片具有很好的功率因数校正功能,各项指标较好地达到了预期的设计要求。更多还原

【Abstract】 In the lighting application, LED (Light Emitting Diode), with many advantages of high luminous efficiency, longevity, high brightness, energy-saving, environmental friendly and durable, is becoming a new lighting source and is being widely applied. However, the use of conventional switch mode power supply, which is used to drive LED, causes the problem that more and more harmonics have been brought to the power system, leading to a heavier harmonic pollution to the electricity network. Thus, it affects the quality of power supply and the security of users. Active power factor correction (APFC) technology is a valid method to improve the power factor of electronic products, reduce electric pollution and harmonic interference. Therefore, APFC technology has emphasized in the research in the promotion of“green electricity network”and“green lighting”today.Based on the project of“Research on Boost APFC Controller”in the Institute of Electronic CAD in Xidian University, a boost APFC controller XD8537 for driving LED is designed. Firstly, the significance of the power factor correction technology and its development status are proposed in the paper. Secondly, the basic topologies of APFC are described, as well as control methods and operate modes. Thirdly, based on the analysis above, the system design, circuit design and simulation have been completed. In view of the disadvantage of the traditional power factor correction chip in slow transient response, a novel high-slew-rate transconductance error amplifier which can safely and promptly deal with the circuit fault, short or the suddenly change of the load is designed. Besides, a variable on-time control method is employed to further optimize the total harmonic distortion (THD).The APFC controller XD8537 designed in the paper is based on 0.4μm 40V BCD process and operates in the critical conduction mode by voltage mode controlling. So it has the characteristics of simple structure, small size and high power factor. The simulation results by HSPICE show that the chip realizes the function of power factor correction (PFC) perfectly, and all the simulation parameters meet the specification well.更多还原