基于峰值I~2C控制的Buck型LED驱动电源研究

发布时间：2018-01-16 14:45

本文关键词：基于峰值I~2C控制的Buck型LED驱动电源研究　出处：《西南交通大学》2017年硕士论文　论文类型：学位论文

【摘要】：发光二极管(Lighting Emitting Diode,LED)以其发光效率高、寿命长、色彩渲染效果好等优点,广泛应用到街道照明、车载照明、液晶显示等工业产品中。由于LED的正向电流决定了它的亮度、使用寿命,为了得到恒定且精度高的正向电流,研究LED驱动电源的恒流控制技术具有重要意义。论文以Buck型LED驱动电源为研究对象,从传统峰值电流型控制技术出发,分析峰值电流控制Buck型LED驱动电源的工作原理,建立其精确的离散迭代映射模型,揭示了电路参数变化时驱动电源的动力学行为;推导了驱动电源的倍周期分岔边界、电感电流连续导电模式(Continuous Conduction Mode,CCM)至断续导电模式(Discontinuous Conduction Mode,DCM)的模式转移边界,并以此研究了 PI补偿器电路参数变化对驱动电源稳定性的影响,通过仿真与实验验证了理论结果的正确性。在峰值电流控制技术的基础上,提出了适用于LED恒流驱动的峰值I~2C控制技术,以及针对Buck型LED驱动电源通过控制外环采样电感电流或是输出电流的两种实现方案;通过仿真分析了峰值I~2C控制Buck型LED驱动电源的稳态性能和瞬态性能,并从时域角度理论分析了输出电容等效串联电阻(Equivalent Series Resistance,ESR)足够大时驱动电源的稳定性问题和斜坡补偿条件。最后,构建了峰值I~2C控制Buck型LED驱动电源的动力学模型,研究了输出电容ESR和控制内环电感电流权重因子对驱动电源动力学特性的影响,并推导了含斜坡补偿的驱动电源倍周期分岔边界、CCM-DCM模式转移边界,并以此划分了驱动电源的工作状态区域分布。研究结果表明:电感电流权重因子、输出电容ESR的减小会缩小驱动电源的稳定工作范围,引入斜坡补偿可以使之拓宽,通过仿真与实验验证了理论分析的正确性和有效性。
[Abstract]:Light emitting diode (LED) is widely used in street lighting because of its high luminous efficiency, long life and good color rendering effect. Vehicle lighting, liquid crystal display and other industrial products. Because the forward current of LED determines its brightness, service life, in order to get constant and high precision forward current. It is of great significance to study the constant current control technology of LED drive power supply. This paper takes the Buck type LED driver as the research object and starts from the traditional peak current mode control technology. This paper analyzes the working principle of Buck type LED drive power supply controlled by peak current, establishes its precise discrete iterative mapping model, and reveals the dynamic behavior of driving power supply when the circuit parameters change. The boundary of period doubling bifurcation and continuous Conduction Mode of inductance current are derived. The mode transfer boundary from CCM) to discontinuous Conduction mode (DCM). The influence of Pi compensator circuit parameters on the stability of the driving power supply is studied. The correctness of the theoretical results is verified by simulation and experiments. Based on the peak-current control technology. In this paper, the peak I ~ 2C control technology suitable for LED constant current drive is put forward, and two schemes are proposed to control the inductance current or output current of the Buck type LED driver by controlling the outer loop sampling inductor current or output current. The steady-state and transient performance of Buck type LED driver with peak I ~ 2C control is analyzed by simulation. The equivalent Series Resistance of output capacitance is analyzed theoretically from the point of view of time domain. The stability of the power supply and the slope compensation condition are discussed when the power supply is large enough. Finally, the dynamic model of the Buck type LED driver with peak value is built. The influence of the output capacitance ESR and the current weight factor of the inner loop inductor on the dynamic characteristics of the driving power supply is studied, and the period doubling bifurcation boundary of the driving power supply with slope compensation is derived. The CCM-DCM mode transfer boundary is used to divide the working state distribution of the driving power supply. The results show that the inductance current weight factor. The reduction of output capacitance ESR will reduce the stable working range of the driving power supply, and the slope compensation can be extended. The correctness and validity of the theoretical analysis are verified by simulation and experiments.
【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】：TM46

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