大功率照明LED驱动控制研究-光学工程专业论文.docx

摘 要 大功率 LED(Light Emitting Diode)作为新一代绿色光源，具有节能、环保和光转 换效率高等特点，在照明应用方面有良好的发展前景。目前的 LED 驱动器主要采用 恒流驱动开关电源，恒流驱动开关电源属于特种电源，发展时间不够长，技术水平 不够成熟，在可靠性和寿命等方面不如传统的稳压性开关电源。本课题主要从可靠 性和效率两方面入手，提出采用两级式驱动结构，前级采用技术成熟可靠的稳压开 关电源，后级采用线性恒流驱动方式，对每路 LED 进行恒流，研究并制作大功率 LED 驱动电路。 本文介绍了 LED 驱动电源的拓扑结构及发展现状，在此基础上提出采用恒压电 源加线性恒流驱动的方式来驱动大功率 LED。在线性恒流驱动方面，介绍了线性恒 流驱动方式的原理，阐述了其设计方法，并采用 MAX16836 设计出线性恒流驱动模 块。实际测试恒流效果好，且效率高。恒流值为 300mA，最高效率可以达到 97.5%； 在 DC/DC(直流/直流)稳压转换器方面，介绍了开关电源的原理结构，着重阐述了 DC/DC 升压型稳压开关电源的设计方法和电源控制系统反馈补偿网络的设计方法。 对转换器主要元件参数和控制系统的反馈补偿网络进行了设计计算，并对整个转换 器系统的电源转换性能和转换器反馈补偿网络进行模拟仿真，给出相关模拟仿真结 果。最后对设计的电源转换器进行实际测试分析，稳压效果好，效率高。稳压输出 电压为 36V，稳压精度为 0.378%，得出系统效率为 90.6%，并与理论模拟和设计计 算的结果相比较得出一致的结果。 综合以上提到的方案，利用线性恒流驱动的 PWM 调光接口做了自适应照明和 色温智能控制两个方面的应用，并给出相关设计方案和结果。 关键词：开关电源 大功率 LED DC/DC 稳压转换器 线性恒流驱动 ABSTRACT High-power LED is a new generation of green light source. It has the characteristics of energy saving and high efficiency. The current LEDs are mainly driven by specially designed constant current driver. It is not as good as the traditional power supply in reliability, and its design is more complex. This project is mainly to study the system reliability and efficiency. LED drivers are with two-stage structure, the first stage using constant voltage power supply, whose technology is mature; the last stage, the linear constant current drive mode, enables each branch of the LED to have a constant current. This article describles the topology of LED driver and its current development. It is proposed by using constant voltage power supply and linear constant current module to drive LED. In linear constant current part, the author introduced the principle of linear constant current driver, described how to design the linear constant current module and designed it with the chip of MAX16836. The actual test result shows that the constant current effect is good and has a high efficiency. The value of the constant current is 300mA, and the maximum efficiency can reach 97.5%. In DC/DC step-up regulator part,