当前能源危机的大环境之下，LED以其高效节能的优势，应用越来越广泛，也越来越趋于多元化，模块化和智能化是LED电源发展的大趋势。本课题在对线性电流源和开关电流源的基本原理、结构、特点深入研究的基础上，设计了两种驱动电源方案，方案一开关电源与线性电流源级联，线性电流源是系统的输出级，利用其输出纹波小、反应速度快的特点，提高输出电流精度；开关直流电压源实时调整输出，减小输出级调整管两端的电压差，提高整个系统的效率；方案二为单级的开关电流源，纹波较大，系统稳定性好。在Matlab/Simulink中分别进行了仿真分析比较，最终选择方案二设计了一台基于ARM7的LED驱动电源。 　　　在控制策略方面，为了保证系统的动态性能和鲁棒性，本设计采用模糊PID控制算法，设计了模糊规则表。根据所设计电源的技术要求，完成了Buck变换器的主电路元件参数设计，在Simulink环境中建立了模糊PID控制的Buck变换器系统模型，进行了仿真，验证了控制策略的正确性以及系统的可靠性。最终设计了以LPC2138为核心控制系统的LED驱动电源，硬件主要包括主电路、电流采样电路、红外硬件电路、MOSFET驱动电路等，软件采用了模块化设计方法，分别对主程序、AD采样程序、模糊PID算法程序、PWM输出程序、红外解码程序、无线调光程序进行了设计。测试结果表明，对该变换器进行的理论分析是正确的，其控制策略是可行的，其性能指标达到了设计要求。

Under the environment of the current energy crisis, LED which takes advantage of high efficiency and energy saving is applied more and more widely and diversely, and the LED power supply is developing towards the direction of modularity and intelligence. In this subject the basic principles, structures and characteristics of linear current source and switching current source have been studied deeply; and two different schemes are designed, the first one switching voltage source and the linear constant current source connected in series, linear DC current source is the output stage. By its small output ripple and fast response, the accuracy of the current can be improved. The switching DC voltage source real-time adjust the output voltage to reduce the voltage difference of the output stage regulator transistor and improve the efficiency of the whole system. The second scheme is switching current source with a bigger ripple and high stability. The two schemes are simulated in the simulink respectively and through analysis and comparison, then a kind of numerical controlled LED drive power supply based on ARM7 are designed according to the second scheme. 　　In the aspect of control strategy, to keep dynamic performance and robustness of the system, this subject adopt fuzzy PID control algorithm, and design the fuzzy rules table. According to technical requirements of the power supply, the design of buck converter circuit components parameters are accomplished. The simulation of the fuzzy PID controlled buck converter model in the simulink verified the correctness of the control strategies and the reliability of the system. Finally the LED drive power supply with the LPC2138 as the core control system is designed, the hardware design mainly includes the main circuit, sampling circuit, infrared hardware circuit and MOSFET drive circuit and so on. Software using the modularization design method, respectively designed the main program, the AD sampling program, fuzzy PID algorithm, PWM output procedure, the infrared decoding program, and wireless dimmer. The test results of experiment show that theoretical analysis of converter is correct, the control strategy is feasible and the performance meet the design requirement.