一种直流电流母线型多路恒流输出LED驱动电源

A Direct Current Bus Type LED Driver With Multiple Constant Current Outputs

在街道路灯照明、隧道照明、景观照明等大功率发光二极管(light emitting diode,LED)照明应用场合,为获得足够的亮度以及高可靠性,需要采用多个LED串来实现,且要求各LED串的驱动电流相等。为此,文中提出一种直流电流母线型多路恒流输出LED驱动电源,包括一个源变换器及多个负载变换器,其中负载变换器的数量与LED串的数量相等。由于所有开关的驱动信号频率和占空比相等,因此只需采用一个电流控制器就实现了多路恒流输出。首先根据两种基本电流源型变换器推演出驱动电源主电路拓扑结构,然后推导其交流小信号模型并采用III型补偿网络进行电流控制器设计,最后搭建一台输出功率为90W的三路输出实验样机并进行相关实验验证,实验结果验证了理论分析的正确性。

In order to obtain sufficient luminance and achieve high reliability, LEDs are usually arranged in LED strings in many high power lighting applications, such as street lamp lighting, tunnel lighting, landscape lighting, etc. Moreover, current imbalance should be avoided among these LED strings. A direct current bus type LED driver with multiple constant current outputs was proposed, which is composed of one source converter and as many load converters as the LED strings. Since all the power switches are switched on and off with the same frequency and duty ratio, only one current controller is needed to realize multiple constant current outputs. Firstly, the topology of the LED driver was presented based on two basic current source type converters. Secondly, its ac small signal model was derived and the design of current controller with a reliable type III compensation network was presented. Finally, a 90 W prototype with three outputs was built and the experimental results were presented, which have verified the correction of the theoretical analysis.