【作者】 杨江涛；

【导师】 刘思久；

【作者基本信息】 哈尔滨工业大学 ， 电气工程， 2008， 硕士

【摘要】 大功率白光LED是近年来新发展起来的一种半导体光源,其发光效率高、无污染、寿命长,而且便于控制亮度,是未来理想的绿色节能照明光源。白光LED具有非线性的负载特性,电源供电电压的微小波动将导致负载电流的剧烈变化。因此为了确保LED的正常工作,需要为其设计专用的电流源驱动器。然而,由于白光LED技术发展很快,层出不穷的新型LED器件和LED应用对驱动器提出了各种不同的要求。因此,本文提出开发基于微控制器管理、能够适应不同场合下车载照明的智能大功率LED驱动器,并建立相应测试系统对其基本性能进行自动测试和系统分析,对于实现LED在特定领域的实际应用、正确评价LED的工作效能,以及进一步普及LED技术,都具有十分重要的意义。本文在分析大功率LED非线性负载特性的基础上,将LED驱动器作为控制系统进行研究;结合PSPICE下的电路仿真试验,提出了一种基于CAN/485总线控制,智能化、输出宽范围可调的电流型LED驱动器的设计思想;并阐述了实际开发过程中的关键技术和实施要点。同时,考虑大功率LED的寿命、光效和色温等关键参数都对温度变化敏感,本文也提出了一种采用半导体制冷器TEC作为LED管体温度控制的新方法,试图以主动散热方式为大功率LED实现长寿、高效和稳定工作开拓新的思路。针对开发LED驱动器本身和检测LED特性的实际需要,本文开发了一种基于虚拟仪器思想的测试系统。并就系统的设计思想、结构特点和一些具体电路进行讨论,介绍了所建具有通用USB控制功能的基础测试模块和测试软件的操作界面,指出了支持VISA标准的典型通用仪器编程控制方法,全面阐述了对电、光、温参数和关键电路波形数据进行自动测试的具体方法。本文最后在说明测试系统使用方法的基础上,给出了所测LED驱动器的各种稳态参数(电流控制线性度、电源调整率、负载调整率、纹波和效率等)和动态参数(开机/关时间、过冲电压和系统动态响应时间的等)、反映性能指标的测试数据及其测试结果的分析曲线,表明所开发的LED驱动器及其自动测试系统的实用性。更多还原

【Abstract】 High power white LED is a new kind of semiconductor light sourcedeveloped in recent years. It’s high efficiency, no pollution, long service life andconvenient control of lightness make it an ideal green energy-saving light source inthe future.With its nonlinear load feature, tiny fluctuation of source voltage willcause marked change of load current. In order to make sure its stable operation,special current driver is needed. Because of rapid development of LED and newLED instrument, special suitable driver is needed. This paper puts forwardintellective high power LED driver suitable for automotive lighting in differentsituation, which is based on MCU management. It also establishes an auto testsystem about its basic performance and systemic analysis. It is important for theevaluation of LED’s service function and making this technique more popular.Based on the analysis of its nonlinear load feature, making LED driver as acontrol system and considering circuit simulation under PSPICE, this paperintroduces a new thought of designing a current mode LED driver which is basedon CAN/485 bus control and intellectively wide range adjustable output. It alsoexplains the key points of the technique in exploitation. Besides, considering thatparameters of high power white LED, such as life-time,light efficiency and color-temperature are sensitive to temperature change, this paper also raises a newmethod in which semiconductor cooler TEC is used to control the LEDtemperature. Depending on this method, An active cooling is proposed as a newdesign idea to carry out the long life-time, high efficiency and stability of highpower white LED. Considering the practical need of developping and testingLED driver, this paper has developed a auto test system based on virtualinstrument thought. It also introduces the operation interface, design idea,structure characteristic and hardware circuit for the basic test module andsoftware which has universal USB control function, points out typical universalinstrument program control method supporting VISA criteria, and explainsdetails of automatic test about electricity, light, teperature parameter and keydataof circuit wave.In this paper, having introduced the use of this test system, It gives out all the steady-state parameters (such as current control linearity, line regulation, loadregulation, ripple and efficiency) and dynamic-state parameters (such as set uptime, hold up time, over voltage and system dynamic response time), the test dataand the analysis curve of the LED driver, which indicates the practicality of theLED driver and its test system developed.更多还原