两级式高功率因数LED照明驱动电源的研究

摘要

In order to solve the disadvantages of the present LED power supply, such as low power factor and large harmonic current, a novel LED power supply with two-stage power factor correction was introduced in this paper. The first PFC stage of the introduced power supply adopts boost topology to improve the power factor, while the sec-ond DC/DC stage adopts quasi-resonant flyback topology to provide constant-current control regulation of the out-put. The PFC stage and the DC/DC stage are controlled by the same controller, which simplifies the circuit struc-ture, and achieves power-factor-correction and constant-curent driving concurrently. The operating principle of power factor correction was analysed in detail, meanwhile, the main design parameters were provided. A prototype of a 12W LED power supply was implemented and tested. The experiment results show that the power factor of the power supply is higher than 0�96, and the circuit design and control method are verified to be correct and effective.%针对目前市场上LED照明驱动电源功率因数低、电流谐波大的问题，介绍了一种改进的两级式高功率因数LED照明驱动电源拓扑。该电源的前级采用Boost拓扑构成功率因数校正级，后级采用准谐振反激式拓扑构成DC/DC功率变换级，两级电路共用一个控制电路，简化了电路结构。分析了实现功率因数校正的控制原理，给出了主要的设计参数。制作一个额定功率为12 W的实验样机，进行功率因数校正、恒流稳压输出等实验，实验结果证明了该设计方案及控制方法的可行性与有效性。