High-brightness light-emitting diode is a promising new generation of green lighting source with the advantages of high efficiency,good optical performance,long lifetime,and environmentally friendly.The lifetime of the LED driver is the bottleneck of the whole system,which limits the LED luminaries' lifetime.Combined with the requirement of the driving current,a LED driver which is driven by the proposed pulsating current is presented.This method can decrease the power ripple in the bus capacitor.Through theoretical analysis,the volume of the bus capacitor can be decreased to 52.7%,while the bus voltage ripple remains same and the input power is high.A prototype of a 50W LED driver has been built and the experimental results are presented.%高亮度发光二极管具有发光能效高、光学性能好、寿命长及环境友好等优点,是极具发展前景的新一代绿色照明光源。但是传统AC供电的LED驱动器中短寿命的电解电容,限制了LED照明光源的长时间使用。本文结合LED驱动器对驱动电流的要求,提出使LED承受一定脉动形式的电流,减小了母线电容承担的脉动功率。通过理论分析得到,在母线电压纹波不变的情况下,储能电容容值最大能够减小到52.7%,从而可以用薄膜电容取代电解电容,并且取得很高的功率因数。分析结果在一台50W的原理样机上进行了验证。
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