Solar Spectrum Fitting Based On LED

In the field of lighting and photovoltaic,it has been proved feasible to manufacture fluorescent light sources through monochrome LED.At present,there are two common methods to simulate sunlight spectrum based on LED.The first method is to use the phenomenon of metamerism to produce a sunlight like light source with excellent temperature close to the color temperature of the sunlight light source.Although the spectrum of this type of light source is somewhat different from the real sunlight spectrum curve,due to the current industrial development level,this method is more suitable for large-scale production.The second method is to simulate LED spectra with different peak wavelengths(WLP)through mathematical models.Within the visible spectral wavelength range of the human eye,multiple LED light sources with different peak wavelengths are used to fit the solar spectrum.The more LED light sources with different peak wavelengths are used,the more accurate the fitting results will be.The advantage of this method is that the reconstructed light source spectrum has a high fit with the sunlight spectrum.And the higher the fitting degree between them,the closer their color temperature,chromaticity coordinates and other attributes will be.The disadvantage is that it is difficult to make LEDs with different peak wavelengths at the current industrial level.This thesis presents a new method to simulate the solar spectrum based on the existing LED light sources.In this way,the LED spectrum simulated by the mathematical model is avoided.The simulation experiment is carried out by designing a filter and adjusting the radiation weight of each existing LED light source(the radiation weight of the LED light source is the percentage of the radiation amount of the current LED light source and the maximum radiation amount of the LED),so as to simulate a new light source and make its spectrum close to the sunlight spectrum.That is,a filter is placed under the mixed light source of multiple LEDs,and the spectrum of the light source is limited by the spectral transmittance of the filter and the radiation weight of each LED light source,so that the corrected spectrum of multiple LED mixed light sources is as close to the spectrum of the sunlight light source as possible.Due to the industrial requirements,the spectral transmittance curve of the filter needs to be smoothed.Finally,the least square solution of the radiation weight of each LED light source is obtained through the spectral transmittance of the optimized filter,so as to obtain the radiation weight of each optimal LED light source.Finally,the method of designing a filter for multiple known LED light sources proposed in this experiment to make the spectral curve of multiple LED mixed light sources after reconstruction as close as possible to the spectral curve of sunlight is applied to two practical directions in this research field.On the one hand,it is applied to health lighting.In the case of night or lack of natural light,lighting through a daylight like light source is conducive to human physical and mental health;On the other hand,it can be widely used in the field of solar energy,such as the detection and calibration of solar cells,the aging resistance test of materials in the building materials industry,and the cultivation of improved varieties in agricultural science.The simulation is carried out through Matlab software,and the final experimental results also prove that the algorithm has important practical application value in the field of lighting and photovoltaic.