基于光量子学的植物照明用自由曲面底板LED光源设计

Design of Plant Lighting LED Lamp with Freeform Surface Substrate Based on Light Quantum Theory

基于光谱的光量子学照明系统评价方法,能使现代农业发光二极管(LED)植物照明系统具有可重复性,具有实用意义。基于光量子理论,采用高出光效率、高均匀度的自由曲面底板设计方法,并使用脉冲宽度调制驱动方法,设计了一款应用自由曲面底板的红蓝光LED植物照明用灯具,并对其参数进行测量。将仿真结果与实验结果进行对比详细分析了传统照明设计方法在LED植物照明中的意义。实验结果表明,所设计的灯具光量子通量密度均匀度约为80%,灯具最高温度约为50℃。由于没有使用扩散板等二次配光手段,灯具出光效率可视为100%,比使用扩散板的情况提高了34.5%以上,大大减少了植物照明的能耗。扩散板的引入会降低所设计灯具的光量子通量密度均匀度,而对混光均匀度影响不大。因此,在植物照明使用的红蓝光LED组合中,使用自由曲面底板的一次配光方法比使用扩散板的二次配光方法更为简便有效,更符合植物照明的设计需求。

The illumination system evaluation method with light quantum theory based on spectra makes light emitting diode（LED） plant lighting system repeatable in modern agriculture, which has practical significance. Based on the light quantum theory, a red/blue LED plant lighting lamp with freeform surface substrate is designed and its parameters are measured with a freeform surface substrate design method, which has high light efficiency and high uniformity, and the pulse width modulation drive method is used. Moreover, the significance of the traditional illumination design method in LED plant lighting is analyzed in detail by comparing the experimental results with the simulation results. The experimental result shows that the photosynthetic photon flux density uniformity of the designed lamp is approximately 80%, and the highest temperature is about 50 ℃. The light efficiency of the lamp can be regarded as 100%, when light diffusion plates and other secondary light distribution methods are not used, and it is 34.5% higher than that of the case when a diffusion plate is used. Energy consumption for plant illumination is reduced greatly. In addition, the use of the diffusion plate will reduce the photosynthetic photon flux density uniformity of designed lamp, but have little influence on light mixing uniformity. Consequently, the primary light distribution method with the freeform surface substrate is more suitable and practical than the secondary light distribution methods with the diffusion plates for the red/blue LED combination in plant lighting.