一种模块化开环多路谐振恒流LED驱动电源

A Modular Open-loop Multi-channel Resonant Constant-current LED Driver

在LCD背光源、路灯照明等LED照明领域,需要多路恒流LED驱动电源来实现更好的性能和更高的可靠性。该文根据LCL-T无源谐振网络的恒流特性,提出一种模块化开环多路谐振恒流LED驱动电源,由一个高频全桥逆变器经变压器隔离变压后接多个LCL-T无源谐振恒流单元组成,一个恒流单元驱动一串LED,易于实现多路输出。文中在输入输出变化范围内保证输出电流均满足恒流精度要求的情况下进行参数设计。最后,搭建一台输出为五路、功率为200W的实验样机,样机效率可达94.7%。实验结果表明,实际输出电流满足恒流精度5%的要求并且实现了软开关,表明通过合理选取参数,可工作在开环模式下。

Many LCD backlighting and street lighting applications require the multi-channel constant-current LED driver to achieve better performance and higher reliability.According to the constant-current characteristic of LCL-T passive resonant network,a modular open-loop multi-channel resonant constant-current LED driver was proposed.It consists of a high-frequency full-bridge inverter followed by an isolation transformer and a serious of LCL-T passive resonant constant-current units.A string of LEDs was driven by one constant-current unit.It is easy to achieve multi-channel constant-current output as needed.And the parameter design is completed to ensure that the output current can meet the constant-current accuracy requirements within the range of input and output.Finally,a 200 W experimental prototype with five channels was built,and the prototype efficiency can reach 94.7%.The experimental results show that the actual output current meets the requirement of 5%constant-current accuracy and the soft switching is realized,which indicates that it can work in open-loop mode by reasonable selection of parameters.