【作者】 王园园；

【导师】 钱照明；

【作者基本信息】 浙江大学 ， 电力电子与电力传动， 2011， 硕士

【摘要】 随着全世界范围内能源危机问题的日益突出,节能减排和环保的要求越来越为人们所重视。照明作为电力能源消耗的一大方面也受到了人们的关注。半导体照明因其节能、环保、寿命长和响应速度快等显著优点,被公认为是21世纪最具发展前景的高技术领域之一。本课题针对大功率LED照明系统设计中的关键技术和存在问题展开了研究。一方面通过比较不同的调光方案对于大功率LED的光效、色温、色坐标以及调光线性度、调光范围和调光效率等性能的影响,分析总结功率LED开关电源调光方案,即模拟调光(AM)和数字调光(PWM)的调光特性和优缺点,为研究高效、高质、长寿环保的可调光LED半导体光源奠定研究基础。第二方面也是本论文重点阐述的内容。适于驱动大功率LED的临界模式单级反激式有源功率因数校正电路(Single-Stage CRM Flyback APFCs)通常都要求具有宽输入电压范围和宽调光范围。而此电路在使用传统控制方法下在高输入电压或轻载时会产生输入电流畸变、THD上升和PF下降的问题。本文针对这个问题分析了临界模式单级反激式有源功率因数校正电路输入电流畸变的分类和来源,由此揭示了在高压输入和轻载情况下输入电流畸变加剧的原因。在此分析基础上提出了一种在原有控制信号中注入正弦平方量的改进控制方法,并就注入的大小对于输入电流谐波削减效果的影响进行了分析,得到了折中不同输入电流畸变影响的最佳注入比范围,是电路在全电压输入范围和全调光范围内均实现了有效的谐波削减。在理论分析的基础上,通过30W临界模式单级反激式有源功率因数校正电路样机验证了改进控制方法的有效性。实验结果表明,在采用合理的注入比下,改进控制方法可以使电路输入电流峰值畸变(Peak Distortion)得到有效地削减且在全输入电压范围和全调光范围内都有较低的THD,以符合国际上对于固态照明SSL(狭义上即指LED半导体照明)的谐波规定,例如欧盟标准IEC61000-3-2和能源之星。更多还原

【Abstract】 At present people pay more and more attention on energy saving and environment protection because of increasing energy crisis around the world. Illumination is one important energy-savable aspect since it is a great deal of energy consumption. Under that circumstance, Light emitting diode (LED) lighting is considered as one of high technology with wide perspective of development in 21st century due to its low power consumption, free pollution, long lifetime and fast response speed.This research mainly focuses on resolving the problems existing in the design process of high power LED lighting system. One aspect is to analyze the effects of different dimming method on luminance efficiency, color temperature, color coordinates, dimming linearity, dimming range and dimming efficiency of light system. Based on that, it can be concluded that advantages and disadvantages of dimming performance with Analogy Modulation (AM) and Pulse-Width Modulation (PWM). It would be the fundament to study high efficiency, high quality dimming method for LED light system.The second aspect which is also the major point of this research is to analyze the reasons of line current distortion of Critical Conduction Mode Single-Stage Flyback Active Power Factor Correctors (CRM SS Flyabck APFC). According to previous analysis, an improved control method is introduced in to reduce line current harmonics by injecting square component of sin(θ). Injected ratio of square component of sin(θ) depends on the variable range of input voltage and output power, consequently it can be fixed in a reasonable range.On the basis of theoretical analysis, the improved control strategy with prop injecting ratio is proved effective on a 30W prototype. In accordance with experimental results, the improved control method with proper injecting ratio of sin(θ) square component, line current peak distortion can be greatly eliminated and the converters can reach lower THD to satisfy the line current harmonics standard of Solid-Stage Lighting(SSL) required by IEC61000-3-2 and Energy Star.更多还原