24 research outputs found
Design Optimization of a High Power LED Matrix Luminaire
This work presents a methodology for optimizing the layout and geometry of an m x n high power (HP) light emitting diode (LED) luminaire. Two simulators are used to analyze an LED luminaire model. The first simulator uses the finite element method (FEM) to analyze the thermal dissipation, and the second simulator uses the ray tracing method for lighting analysis. The thermal and lighting analysis of the luminaire model is validated with an error of less than 10%. The goal of the optimization process is to find a solution that satisfies both thermal dissipation and light efficiency. The optimization goal is to keep the LED temperature at an acceptable level while still obtaining uniform illumination on a target plane. Even though no optical accessories or active cooling systems are used in the model, the results demonstrate that it is possible to obtain satisfactory results even with a limited number of parameters. The optimization results show that it is possible to design luminaires with 4, 6 and up to 8 HP-LEDs, keeping the LED temperature at about 100 degrees C. However, the best uniformity on a target plane was found by the heuristic algorithm
Design Optimization of a High Power LED Matrix Luminaire
This work presents a methodology for optimizing the layout and geometry of an m x n high power (HP) light emitting diode (LED) luminaire. Two simulators are used to analyze an LED luminaire model. The first simulator uses the finite element method (FEM) to analyze the thermal dissipation, and the second simulator uses the ray tracing method for lighting analysis. The thermal and lighting analysis of the luminaire model is validated with an error of less than 10%. The goal of the optimization process is to find a solution that satisfies both thermal dissipation and light efficiency. The optimization goal is to keep the LED temperature at an acceptable level while still obtaining uniform illumination on a target plane. Even though no optical accessories or active cooling systems are used in the model, the results demonstrate that it is possible to obtain satisfactory results even with a limited number of parameters. The optimization results show that it is possible to design luminaires with 4, 6 and up to 8 HP-LEDs, keeping the LED temperature at about 100 degrees C. However, the best uniformity on a target plane was found by the heuristic algorithm
Increasing photovoltaic panel power through water cooling technique
This paper presents the development of a cooling apparatus using water in a commercial photovoltaic panel in order to analyze the increased efficiency through decreased operating temperature. The system enables the application of reuse water flow, at ambient temperature, on the front surface of PV panel and is composed of an inclined plane support, a perforated aluminum profile and a water gutter. A luminaire was specially developed to simulate the solar radiation over the module under test in a closed room, free from the influence of external climatic conditions, to carry out the repetition of the experiment in controlled situations. The panel was submitted to different rates of water flow. The best water flow rate was of 0.6 L/min and net energy of 77.41Wh. Gain of 22.69% compared to the panel without the cooling system
Calculation of Grounding Grids Parameter at Arbitrary Geometry
This paper deals with the computation of ground resistance, surface voltage, touch voltage and step voltage, to mesh with horizontal wires arranged in different angles. The computer program implemented used in the mathematical modeling is based on the method proposed by Heppe, which allows obtaining the grounding parameters for homogeneous soil and soil stratified in two layers. The results obtained with the proposed method will be compared with other methods in literature. Also will be presented the results of a grounding grid using wires at various angles
Simulation and analysis of an isolated full-bridge DC/DC boost converter operating with a modified perturb and observe maximum power point tracking algorithm
The purpose of the present study is to simulate and analyze an isolated full-bridge DC/DC boost converter, for photovoltaic panels, running a modified perturb and observe maximum power point tracking method. The zero voltage switching technique was used in order to minimize the losses of the converter for a wide range of solar operation. The efficiency of the power transfer is higher than 90% for large solar operating points. The panel enhancement due to the maximum power point tracking algorithm is 5.06%
Simulation and analysis of an isolated full-bridge DC/DC boost converter operating with a modified perturb and observe maximum power point tracking algorithm
The purpose of the present study is to simulate and analyze an isolated full-bridge DC/DC boost converter, for photovoltaic panels, running a modified perturb and observe maximum power point tracking method. The zero voltage switching technique was used in order to minimize the losses of the converter for a wide range of solar operation. The efficiency of the power transfer is higher than 90% for large solar operating points. The panel enhancement due to the maximum power point tracking algorithm is 5.06%
Methodology for Measurement the Energy Efficiency Involving Solar Heating Systems Using Stochastic Modelling
The purpose of the present study is to evaluate gains through measurement and verification methodology adapted from the International Performance Measurement and Verification Protocol, from case studies involving Energy Efficiency Projects in the Goias State, Brazil. This paper also presents the stochastic modelling for the generation of future scenarios of electricity saving resulted by these Energy Efficiency Projects. The model is developed by using the Geometric Brownian Motion Stochastic Process with Mean Reversion associated with the Monte Carlo simulation technique. Results show that the electricity saved from the replacement of electric showers by solar water heating systems in homes of low-income families has great potential to bring financial benefits to such families, and that the reduction in peak demand obtained from this Energy Efficiency Action is advantageous to the Brazilian electrical system. Results contemplate also the future scenarios of electricity saving and a sensitivity analysis in order to verify how values of some parameters influence on the results, once there is no historical data available for obtaining these values
Proposal of heuristic regression method applied in descriptive data analysis: case studies
The purpose of this paper is to use the hybridized optimization method in order to find mathematical structures for analysis of experimental data. The heuristic optimization method will be hybridized with deterministic optimization method in order to that structures found require not knowledge about data generated experimentally. Five case studies are proposed and discussed to validate the results. The proposed method has viable solution for the analysis of experimental data and extrapolation, with mathematical expression reduced
Optimization Process Applied in the Thermal and Luminous Design of High Power LED Luminaires
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
Optimization Process Applied in the Thermal and Luminous Design of High Power LED Luminaires
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