Citation: Barbosa, J.L.F.; Coimbra, A.P.; Simon, D.; Calixto, W.P. Optimization Process Applied in the Thermal and Luminous Design of High Power LED Luminaires. Energies 2022, 15, 7679. https:// doi.org/10.3390/en15207679 Academic Editor: José Torres Farinha Received: 17 August 2022 Accepted: 29 September 2022 Published: 18 October 2022 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). energies Article Optimization Process Applied in the Thermal and Luminous Design of High Power LED Luminaires Jose Luiz F. Barbosa 1,2, * , Antonio P. Coimbra 3 , Dan Simon 4 and Wesley P. Calixto 1,2,3, * 1 Electrical, Mechanical & Computer Engineering School, Federal University of Goias, Goiania 74605-010, Brazil 2 Studies and Researches in Science and Technology Group, Federal Institute of Goias, Goiania 74055-110, Brazil 3 Institute of Systems and Robotics, University of Coimbra, 3030-290 Coimbra, Portugal 4 Department of Electrical Engineering and Computer, Cleveland State University, Cleveland, OH 44115, USA * Correspondence: jose.luiz@ifg.edu.br (J.L.F.B.);wpcalixto@pq.cnpq.br (W.P.C.) Abstract: This work proposes the design of an optimization method for high-power LED luminaires with the introduction of new evaluation metrics. A luminaire geometry computational method is deployed to conduct thermal and optical analysis. This current effort novels by designing a tool that enables the analysis of uniformity for individual luminaire over the target plane in accordance with international regulatory standards. Additionally, adequate thermal management is conducted to guarantee nominal operation standard values determined by LED vendors. The results of this optimization method present luminaire models with different geometries that allow the stabilization of the temperature within the safety and uniform illuminance distribution thresholds. The resulting solution proposes the design of a 2 × 2 HP-LED rectangular luminaire. During simulations, the temperature of the LED reaches a maximum value of 73.9 ◦ C in a steady state with a uniform index of 0.228 for its individual luminaire. The overall uniform index identified for two separate and adjacent luminaire points in a pedestrian walk is 0.5413 with a minimal illuminance of 36.95 lx, maximum illuminance of 93.65 lx and average illuminance of 68.27 lx. Overall, we conclude that the currently adopted metric, which takes into consideration only the ratio between the minimum and the average illuminance, is not efficient and it cannot distinguish different luminaire geometry standards according to their uniform illuminance distribution. The metric proposed and designed in this work is capable of evaluating illuminance and thermal threshold criteria, as well as classifying different sorts of luminaries. Keywords: LED luminaire; illuminance distribution; thermal heat dissipation; optimization process; high power light emitting diode 1. Introduction Artificial lighting represents an area of research that has a high consumption of electricity, as it is considered an essential application for quality of life [1–7]. In the absence of natural light, it makes it possible to carry out commercial and leisure activities, among many others, in addition to promoting a feeling of security. This dependence on searches for energy efficiency in lighting sources is a challenge for researchers around the world [2,4,5,8]. Solid state light sources (SSL) have made progress in recent years, with light-emitting diodes (LEDs) being their biggest representative. These have progressed in terms of improving lamp efficiency and color quality to compete and even surpass traditional technologies in various applications [3]. LED’s compact size allows optical designs to be more flexible. Additionally, LEDs incorporate other advantages when compared to traditional lighting sources, such as: (i) long lifespan, (ii) high brightness, (iii) low power consumption, (iv) fast response, (v) compact size, (vi) high reliability [3,9,10] and (vi) mechanical shock and vibration resistance [11]. However, there are still some difficulties in using luminaires with high- power LED (HP-LED). In addition to the high financial cost compared to other lighting Energies 2022, 15, 7679. https://doi.org/10.3390/en15207679 https://www.mdpi.com/journal/energies