摘要随着照明行业的不断发展，LED 灯以其高效率，节能，发光亮度高等优点 逐渐占据市场的主导地位。因为 LED 发光亮度是由电流大小决定的，所以要 实现 LED 发光亮度恒定，就需要一个性能优良的恒压恒流驱动器。77289

本次设计采用 Buck（降压型）作为恒压恒流开关电源整体设计的拓扑电路 结构。通过变压、整流、滤波电路可以把高压交流电源变为 LED 直流驱动电源， 实现对多个串联大功率 LED 的电流控制。开关电源设定为 50mA/500mA 的 LED 调光电流。最高可驱动 2A 的大功率 LED，工作频率为 100kHz-500kHz。探索 恒压恒流开关电源在路灯、交通灯等领域应用。

分析应用 Buck（降压型）电路作为恒压恒流开关电源的优点与缺点，划分 电路设计方案，把电路模块化设计。设计中主要优化恒压恒流开关电源的设计 问题，提出几种电路设计拓扑机构，并进行比较选出合适的设计电路。采用 BT-SIM 电路软件进行搭建模块，并进行仿真，测试电路的整体运行良好程度， 并进行评估电路是否达到预期的设计目标。通过对仿真数据分析，本次恒压恒 流开关电源的设计实现了设定的功能，能够保持大功率 LED 发光亮度的恒定。

毕业论文关键词：恒压恒流；开关电源；大功率 LED

Abstract With the continuous development of the lighting industry, LED lamp with its advantages, such as high efficiency, energy saving, hi-lite, gradually dominate the market。 Because the LED brightness is determined by the size of the current, so to achieve LED brightness constant, we need a good performance constant voltage constant current driver。

The design uses Buck (step-down) constant voltage and constant current switching power supply as the topology of overall design。 By transformer, rectifier, filter circuit may turn the high-voltage AC power into DC LED driver power supply, to achieve a plurality of series of high-power LED current control。 Switching power supply is set to 50mA / 500mA of LED current dimming。 The maximum driving high-power LED’s run up to 2A, and the operating frequency ranges from 100kHz to 500kHz。 We will explore constant voltage and constant current switching power supply applications in the direction of the street lights, traffic lights and other fields。

Analysis the advantages and disadvantages of Buck (step-down) circuit as the topology constant voltage and constant current switching power supply, make the pision circuit design, and build modular design of the circuit。 Optimized design of the main constant voltage and constant current switching power supply design issue, propose several circuit topology design agency, and compare them to choose the right design of the circuit。 BT-SIM circuit using software building blocks, and simulation, test how well the overall operation of the circuit, and assess whether the circuit to achieve the desired design goals。 According to the simulation data analysis, the constant voltage and constant current switching power supply’s design achieve the set of capabilities, high-power LED brightness can be maintained constant。

Keywords: constant voltage and current; switching power supply; high-power LED

目录

第一章  绪论 1

1。1 引言 1

1。2 研究意义 1

1。3 国内外研究现状及存在的问题 2

1。4 本论文的主要工作 3

第二章  开关电源的理论基础 5

2。1 开关电源的拓扑结构 5

2。1。1 非隔离式开关电源