DESIGN METHODOLOGY AND DEVELOPMENT OF A FLEXIBLE LIGHT SIMULATOR BASED ON LIGHT-EMITTING DIODES

Abstract

This work presents the design and development of a lighting system based on light emitting diodes (LEDs) capable of accurately reproducing light spectra for applications that require a specific light spectrum. The proposed methodology uses Mathematical Programming, using a Mixed Integer Linear Programming model, to obtain the optimal combination of LED models that result in the spectrum as close as possible to the reference. The LEDs of each model selected by the optimization procedure are driven by an electronic Manuscript received 04/23/2020; first revision 07/31/2020; accepted for publication 09/01/2020, by recommendation of Editor Demercil de Souza Oliveira Jr. http://dx.doi.org/10.18618/REP.2020.3.0025 system composed of Buck converters with current control by hysteresis and control of light intensity by Pulse Width Modulation. The independent control of each LED model allows the possibility to vary the intensity and the spectral distribution of the light, adding flexibility to the lighting system. As a practical application, a system is developed to reproduce the spectrum of sunlight for different times of the day. Tests to validate the proposed methodology demonstrated that it is possible to reproduce certain spectra with fidelity, with an average relative error of 12% between the designed spectrum and the reference spectrum, considering the LED models available.