PWM调制占空比对混合白光LED光源光色度的影响  

The Influence of Duty Ratio of PWM Modulation on Photometric and Colorimetric Quantity of Mixture of White LEDs

作　　者：胡奕彬 刘士伟[1] 刘思远[1] 刘腾方 胡乐[1] 庄其仁[1] 

机构地区：[1]华侨大学信息科学与工程学院,福建厦门361021

出　　处：《照明工程学报》2016年第2期54-58,共5页China Illuminating Engineering Journal

基　　金：福建省科技计划重点项目(2012H0029);泉州市科技计划项目(2014Z105)

摘　　要：脉冲宽度调制(PWM)是LED照明光源智能控制的常用方法,为了准确控制混合白光LED光源的光度和色度,本文研究了基于两种不同色温白光LED的混合光源双通道PWM调制光色度理论模型,推导出混合光源色坐标、相关色温、最大亮度与双通道调制脉冲占空比比值的关系式。采用暖白光(色温3282K)和冷白光(色温12930K)两种白光LED进行混色实验,通过单片机控制脉冲宽度实现占空比可调。结果显示实验测量值与理论计算值吻合很好,证明理论模型的正确性。实验结果同时表明采用双通道PWM调节混合光源的色坐标和色温时,在相关色温4233K^7316K范围内可以保证光源亮度(光通量)输出值不低于最大值的70%。Pulse width modulation（ PWM） is a common method for LED in intelligent lighting. In order to control photometric and colorimetric quantity of mixed light source of white LED accurately,this paper studies the photometric and colorimetric theoretical model of two channels ＇ PWM based on mixed light source of the two kinds of white LED with different color temperatures, deducing the formula for chromaticity coordinate of mixed light source,correlated colour temperature,maximum luminance and ratio of duty ratio of two channels＇ PWM. Two white LED samples of low color temperature（3282K） and high color temperature（12930K） were mixed in experiment,changing the duty ratio by controlling the pulse width. The results show that the experimental results are in fairly good agreement with the theoretical value,proving the correctness of the theoretical model. The results also show that we can ensure the luminous flux is higher than 70% of maximum in the range of 4233 K to 7316 K, when adjusting the chromaticity coordinate and correlated colour temperature of mixed light source by two channels＇ PWM.

关 键 词：白光LED 光色度 PWM 占空比 

分 类 号：TM923.34[电气工程—电力电子与电力传动]