改进型峰值电流控制的大功率LED驱动电源设计

发布时间：2018-04-06 22:39

本文选题：LED照明　切入点：峰值电流控制模式　出处：《中国照明电器》2015年11期

【摘要】：发光二极管(LED)的U-I特性适合采用恒流电源驱动。由于峰值电流控制的模式简单方便,在LED驱动电路中常采用双环峰值电流控制,使大功率LED的驱动电源稳定工作。但是当电源的占空比超过50%且电感电流连续时,峰值电流控制模式就存在次谐波振荡的问题,当电流内环被噪声或瞬态干扰时就不能精确控制LED发光亮度。在双环峰值电路控制中加入斜坡补偿信号,能有效解决次谐波振荡引起的问题。因为LED的负温度效应会使输出电压降低从而引起LED的损坏,所以将传统双环峰值电路中的电压外环改进为电流外环,改善了LED的负温度效应引起的问题。最后通过数字仿真软件Multisim 10对改进后的双环峰值电流控制系统进行了性能验证。
[Abstract]:The U-I characteristic of LED) is suitable for constant current power supply.Because the mode of peak current control is simple and convenient, double loop peak current control is often used in LED drive circuit, which makes the driving power supply of high power LED work stably.However, when the duty cycle of the power supply exceeds 50% and the inductor current is continuous, the peak current control mode has the problem of sub-harmonic oscillation, and the luminance of LED cannot be accurately controlled when the current inner loop is affected by noise or transient interference.The problem caused by subharmonic oscillation can be effectively solved by adding slope compensation signal to the control of double loop peak circuit.Because the negative temperature effect of LED can reduce the output voltage and cause the damage of LED, the voltage outer loop in the traditional double loop peak circuit is improved to the current outer loop, which improves the problem caused by the negative temperature effect of LED.Finally, the performance of the improved dual loop peak current control system is verified by digital simulation software Multisim 10.
【作者单位】：长春工业大学电气与电子工程学院;
【基金】：吉林省科技支撑计划项目(20106034)资助
【分类号】：TN312.8;TN86

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