一种基于重复控制的无电解电容 LED驱动电源

杨明杰 廖建彬

摘要：LED 驱动电源大多使用了容量较大的电解电容作为储能滤波元件，然而其平均寿命远低于 LED 器件，限制了驱动电源的使用寿命和电源功率的进一步提升。针对该问题，设计了一种基于重复控制的无电解电容 LED驱动电源，采用 Boost功率因数校正电路，提高输入功率因数，此外，利用 Buck/Boost变换器进行升压储能，并结合周期性重复控制算法，对儲能实施调节，从而达到输入脉动功率与输出恒定功率之间的平衡，使负载 LED 获得恒定电流。由于没有采用大容量的电解电容，因而提高了 LED驱动电源的使用寿命。最后，搭建了一套基于重复控制算法的无电解电容 LED驱动电源，测得输入功率因数为0.97，恒定输出的电流纹波系数为3%。

关键词：LED驱动;功率因数校正;无电解电容;恒流

中图分类号：TM46             文献标志码：A        文章编号：1009-9492（2021）12-0068-03

An Electrolytic Capacitor-less LED Driver Based on Repetitive Control

Yang Mingjie ，Liao Jianbin

（Minnan University of Science and Technology， Shishi， Fujian 362700， China）

Abstract： Electrolytic capacitors with large capacity are often used as energy storage and filter elements for LED driver. However， its average life is far lower than that of LED devices， which will restrict the lifetime of driver and the further increment of power. In order to solve this problem， an electrolytic capacitor-less LED driver based on repetitive control was designed. Boost power factor correction circuit was used to improve the power factor of input. In addition， Buck/Boost converter was adopted to boost voltage for energy storage， combining with periodic repetitive control algorithm to adjust the energy storage， so as to achieve the balance between pulsating power of input and constant power of output， and obtain constant output current for LED loads. Since no electrolytic capacitor with large capacity was used， the lifetime of the LED driver was prolonged. Finally， a set of LED driver without electrolytic capacitor based on repetitive control algorithm was built. The test results show that power factor of the input is 0.97 and the ripple coefficient of direct current output is 3%.

Key words： LED driver; power factor correction （PFC）; electrolytic capacitor-free; constant output current

0 引言

发光二极管（Lighting Emitting Diode ，LED ）是一种新型的半导体冷光源，发光效率高、节能环保、可靠性高、寿命长、体积小、成本低，在很多使用场合逐步替换传统的白炽灯，有着巨大前景。同时，要求 LED 的驱动电源应当具备高功率因数、高可靠性、长寿命。目前，LED 驱动电源大多使用了容量较大的电解电容作为储能滤波元件，然而其平均寿命与半导体器件 LED 相比，相差悬殊，成为影响 LED 驱动电源寿命的主要瓶颈，并且会限制电源功率的进一步提高。因此，需要研制一种无电解电容的 LED 驱动电源，延长 LED 驱动电源的使用寿命，并且校正功率因数，减小输出电流的纹波，使得流过 LED 的电流近似恒定。……