PFM控制交错并联反激LED驱动电源研究

Research on Interleaved Flyback LED Driving Power Supply Controlled by PFM

半导体照明具有节能、环保、寿命长、尺寸小等优点,发光二极管(LED)作为新型半导体光源在户外照明领域已经有了广泛的应用。针对传统单级式和两级式LED驱动电源存在的问题,研究一种结构简单、功率等级高的交错并联反激LED驱动电源,同时提出一种PFM控制方法,根据不同负载情况,改变驱动电源开关频率和导通时间,减小轻载时开关损耗,提高工作效率,实验结果验证了理论分析的正确性。

Light emitting diode （LED）has the virtues of energy conservation, environment protection , long lifetime and compact size. It has been widely used in a lot of outdoor lighting applications as a new semiconductor light source. To solve the problems in the traditional single-stage and two-stage structures, a simply structural with a high power level interleaved flyback LED driving power supply has been researched. In the meantime, a PFM control method has been proposed, which will change the switching frequency and the turn-on time according to the different load conditions, so as to reduce the switching loss in light load condition and improve the efficiency of the LED driver. Experiment results verify the correctness of the theory analysis.