初级侧控制准谐振LED驱动电源的研究

Research on Quasi-Resonant LED Power Supply Based on Primary Side Control

针对LED驱动电源设计上所存在的问题,本文基于初级侧控制及准谐振技术,设计了一款12W的LED照明驱动电源,该电源采用单端反激式准谐振电路作为其主电路拓扑,并在其前端增加了boost功率因数校正电路,主电路和功率因数校正电路的开关管均由一个控制芯片iw3614统一控制;同时,给出了初级侧控制的准谐振LED驱动电源的准谐振模式及恒压和恒流的控制原理及电源的各项设计参数,并做了准谐振开通、恒压和恒流等相关实验.实验结果表明,该电源实现了开关管的准谐振开通,输出电压稳定在30 V,输出电流稳定在372 mA,具有较好的恒压恒流特性;当输入电压在180～264 V变动时,功率因数均在0.96以上,电源的效率大约为82％,实现了功率因数校正与恒压恒流输出.该电源具有结构简单、恒压恒流特性好、开关损耗较小、功率因数高等优点,能高效、可靠地驱动LED灯工作.

In order to solve the problems on design of the LED drive power supply, a 12W lighting drive power supply based on primary side control and quasi-resonant technology was designed. The main circuit of the power supply was single-stage flyback quasi-resonant topology and a boost power factor correction circuit was added in its front. The main circuit and the power factor correction circuit by a switch control chip iW3614 unified control. At the same time the quasi-resonant mode and constant voltage constant cur- rent principle of the power supply based on primary side control have been elaborated. Then the design pa- rameters of the power supply were given, and the experiment of quasi-resonant switch and constant voltage constant current has been done. The results show that the power supply to achieve a quasi-resonant open- ing of the switch, while the output voltage was stabilized at 30 voltage, and the output current was stabi- lized at 372 ampere, has good constant voltage constant current characteristics. When the input voltage was 180- 264V, power factors were above O. a power factor correction and constant voltage ges of simple structure, good constant vo tag factor can work efficiently and reliably drive 96, and the power efficiency was about 82 %, which achieves constant current output. The power supply has the advanta- e constant current characteristics, small loss, and high power LED lights.