谐振式单开关多路输出Boost LED驱动器研究

发布时间：2018-04-01 15:27

本文选题：谐振　切入点：单开关　出处：《西南交通大学》2017年硕士论文

【摘要】：在许多高流明应用场合,如大型LCD背光、路灯照明等,为了获得均匀的光通量,需要多路LED输出均流。与有源多路均流输出技术相比,无源多路均流输出技术具有电路结构简单、体积小、成本低、效率高等特性。鉴于电容-二极管无源多路均流输出方案还具有电路控制简单、均流精度高等优点,因此本文对电容-二极管多路均流拓扑的工作规律进行研究。研究结果表明:电容-二极管2n-1路和2n路均流拓扑因电路结构有所差异,导致两电路中二极管导通顺序的规律不同。采用隔离和非隔离型谐振变换器给电容-二极管多路均流拓扑提供高频交流母线电流,可以推演得到七种隔离和非隔离型谐振式电容-二极管多路均流拓扑。由于七种隔离和非隔离型谐振式电容-二极管多路均流拓扑的均流原理相同,以谐振式单开关多路输出Boost LED驱动电路为例,分析了谐振式单开关2n-1路和2n路输出Boost LED驱动电路工作在连续模式(continuous conduction mode,CCM)的工作原理和工作特性。谐振式单开关2n-1路或2n路输出Boost LED驱动电路只需要使用一个开关管、一个谐振电感、2n-2个或2n-1个谐振电容就能实现2n-1路或2n路输出的恒流控制,具有电路结构与控制简单、体积小、均流精度高、效率高以及成本低的特点。利用谐振电容的充放电平衡原理,仅需控制其中任意一条输出支路电流恒定,即可自动实现2n-1路或2n路输出支路的恒流及均流控制。此外,该多路恒流输出LED驱动电路还具有天然的短路保护特性,任何一条输出支路短路不会影响其它输出支路的稳态电流。最后,搭建了一台36W的三路恒流输出实验样机和一台48W的四路恒流输出实验样机,验证了理论分析的正确性。
[Abstract]:In many high lumen applications, such as large LCD backlight, street lamp lighting and so on, in order to obtain uniform luminous flux, multi-channel LED output current equalization is required. The passive multichannel current sharing output technology has the advantages of simple circuit structure, small volume, low cost and high efficiency. In view of the advantages of the capacitance-diode passive multi-channel current sharing output scheme, the circuit control is simple, the current sharing accuracy is high, and so on. Therefore, in this paper, the working rules of capacitance-diode multichannel current sharing topology are studied. The results show that the capacitance diode 2n-1 circuit and 2n channel current sharing topology are different from each other because of the circuit structure. The order of diode conduction is different between the two circuits. The isolated and non-isolated resonant converters are used to provide high-frequency AC bus current to the capacitor-diode multichannel current-sharing topology. Seven isolated and non-isolated resonant capacitance-diode multichannel current-sharing topologies can be derived. Because of the same current-sharing principle of the seven isolated and non-isolated resonant capacitance-diode multichannel current-sharing topologies, Taking the resonant single-switch multi-channel output Boost LED drive circuit as an example, The operating principle and characteristics of resonant single-switch 2n-1 circuit and 2n output Boost LED drive circuit operating in continuous conduction mode are analyzed. The resonant single-switch 2n-1 circuit or 2n-channel output Boost LED drive circuit only needs one switching tube. A resonant inductor with 2n-2 or 2n-1 resonant capacitors can realize the constant-current control of 2n-1 or 2n output. It has the advantages of simple circuit structure and control, small volume and high current sharing precision. The characteristics of high efficiency and low cost. Based on the charge / discharge balance principle of resonant capacitor, the constant current and current sharing control of 2n-1 or 2n output branch can be realized automatically by only controlling the constant current of any one of the output branches. The multi-channel constant-current output LED drive circuit also has the nature short-circuit protection characteristic, any output branch short-circuit will not affect the steady state current of the other output branch. Finally, A 36W experimental prototype of three-channel constant-current output and a 48W experimental prototype of four-way constant-current output are built to verify the correctness of the theoretical analysis.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN312.8

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