scholarly journals Analysis of Electric Power Quantities of Road LED Luminaires under Sinusoidal and Non-Sinusoidal Conditions

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1109
Author(s):  
Roman Sikora ◽  
Przemysław Markiewicz
Keyword(s):  
Supply Voltage ◽  
Light Emitting Diode ◽  
Luminous Flux ◽  
Laboratory Measurements ◽  
Electrical Parameters ◽  
Light Emitting ◽  
Road Lighting ◽  
Legal Provisions ◽  
Acceptable Range ◽  
Deformation Level

The paper presents the results of laboratory tests concerning the measurements of electrical parameters of road lighting luminaires. These measurements were focused on determining the dependence of the electrical parameters of the luminaires versus the changes of the RMS (Root Mean Square) value of the supply voltage and the level of disturbances in the supply voltage. The basic electrical parameters for light-emitting diode (LED) luminaires were analysed with the option of luminous flux adjustment if it existed. During the laboratory measurements, the luminaires were powered from the Agilent 6834B distorted voltage generator within the assumed acceptable range of the changes in the deformation level resulting from the applicable legal provisions for the reproduction of actual power supply conditions.

scholarly journals The influence of power electronic converter passive filter parameters for flicker in LED lighting

2018 ◽  
Vol 21 ◽  
pp. 00020
Author(s):  
Dariusz Sobczynski
Keyword(s):  
Power Systems ◽  
Supply Voltage ◽  
Current Source ◽  
Luminous Flux ◽  
Light Sources ◽  
Light Emitting ◽  
Current Voltage ◽  
Passive Filters ◽  
The Stability

The light emitting diodes (LEDs) are ever more used, and their price is getting lower year on year. Although, exchanging traditional light sources for the LED lamps does not seem to be complicated, we need to remember to maintaining high–quality of light. One of the aspects we should be worry about is a light’s flickering. Due to the shape of the current–voltage characteristics of the LED diode and their dependence on temperature, the value of the luminous flux – but also the lifetime – depends to a large extent on the stability of the supply voltage. Therefore, correct power system should be a thermally stable current source. Unfortunately, the simple power systems, equipped with passive filters are often used as cheap commercial solutions. In those types of systems stability of the output voltage is heavily dependent on the load conditions. Passive filters – usually consisting of coils and capacitors – are placed in the output circuit. This paper presents research carried out to show of filter capacitance influence on flickering phenomenon, and practical light’s flickering measuring technique for the LED lamps.

scholarly journals Dispensing Technology of 3D Printing Optical Lens with Its Applications

Energies ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 3118 ◽  
Author(s):  
Fang-Ming Yu ◽  
Ko-Wen Jwo ◽  
Rong-Seng Chang ◽  
Chiung-Tang Tsai
Keyword(s):  
Solar Cells ◽  
Light Emitting Diode ◽  
Contact Angles ◽  
Luminous Flux ◽  
Photoelectric Conversion Efficiency ◽  
Fluid Viscosity ◽  
Photoelectric Conversion ◽  
Uv Curable ◽  
Lens Array ◽  
Light Emitting

Current 3D printed lens technology faces reduced efficiency due to stepped and stacked lens surfaces. This research employs a faster jet dispensing method which reduces these issues. It uses UV-curable material and merges droplets before they are cured to obtain very smooth lens surfaces without any post-processing and without manufacturing a mold for lens structures. This technology can be applied to lens manufacturing in a variety of products, especially in the form of arrays, saving development time and reducing cost. Two experiments of LED (Light-emitting diode) lens and solar cell lens array mask implementations are presented to demonstrate the power of the method. Furthermore, this study analyzes the effect of different contact angles created by jet dispensing technology, including a detailed exploration of fluid viscosity and tooling heating parameters. Our results show that the LED lens can be manufactured to increase the luminous flux of large angles. Furthermore, the lens array mask for solar cells can be manufactured to reduce sunlight reflection and increase secondary refraction, which enables solar cells to achieve higher photoelectric conversion efficiency and to increase their power generation up to 4.82%.

scholarly journals The Effect of Different Filament Arrangements on Thermal and Optical Performances of LED Bulbs

2020 ◽  
Vol 10 (4) ◽  
pp. 1373
Author(s):  
Wei Wang ◽  
Jun Zou ◽  
Qiaoyu Zheng ◽  
Yuefeng Li ◽  
Bobo Yang ◽  
...  
Keyword(s):  
Thermal Cycle ◽  
Gas Flow ◽  
Performance Test ◽  
Light Emitting Diode ◽  
Luminous Flux ◽  
Junction Temperature ◽  
Test Results ◽  
Light Emitting ◽  
Three Samples ◽  
Simulation Results

The influences on thermal and optical performances of light emitting diode (LED) bulbs with three different filament arrangements are investigated in detail. The average junction temperature, temperature of the surface of the bulb, and luminous flux of three samples all increased with increasing power. The thermal performance test results show that between the average junction, temperature and power were linear. The junction temperatures of the three samples at a power of 3.5 W were 102.48, 98.46, and 88.88 °C. The optical performance test results revealed that the luminous flux and efficiency in the two vertical filament arrangements were closely related to each other and higher than that of the horizontal filament arrangement. A numerical model of LED filament bulbs was established by the Floefd 17.2 software for analyzing the temperature distribution of the cross section and the gas flow path inside the bulb. The simulation results illustrated that the average temperatures of three samples were 105.88, 101.83, and 96.12 °C. Additionally, the gas flow inside the bulb of the two vertical filament arrangements was subject to forming a thermal cycle during operation work more than that of the horizontal filament arrangement. As a result, the flexible spiral LED filament bulb is feasible as a new light source.

scholarly journals Optimization and scale-up of an LED-illuminated microalgal photobioreactor for wastewater treatment

2019 ◽  
Vol 80 (12) ◽  
pp. 2352-2361
Author(s):  
L. M. L. Silva ◽  
A. F. Santiago ◽  
G. A. Silva ◽  
A. L. P. Castro ◽  
L. S. Bastos ◽  
...  
Keyword(s):  
Organic Matter ◽  
Wastewater Treatment ◽  
Wastewater Treatment Plants ◽  
Light Emitting Diode ◽  
Scale Up ◽  
Operating Time ◽  
Luminous Flux ◽  
Light Emitting ◽  
Operational Conditions ◽  
Nitrogen Phosphorus

Abstract The use of light-emitting diode (LED)-illuminated photobioreactors with microalgae has been extensively studied for wastewater treatment. Most studies have used isolated microalgae species; however, this practice does not match the reality of conditions in wastewater treatment plants. Operational conditions that promote greater growth of algal biomass and that remove pollutants most effectively are disputed in the literature. In this context, LED-illuminated photobioreactors with microalgae were evaluated using multivariate analysis in order to optimize removal of pollutants (nitrogen, phosphorus, and carbonaceous organic matter). Three variables were evaluated: operating time, LED wavelength, and luminous flux intensity. A microalgae consortium was used in the photobioreactor. In addition to the LED-illuminated photobioreactors, control photobioreactors illuminated by sunlight were also operated. Using the results obtained in the optimization, a scaled-up reactor approximately 8.5 times larger in volume was operated to evaluate if the behavior would be maintained. The best operational conditions for the removal of pollutants were observed in LED-illuminated photobioreactors operated under a light intensity of 700 μmol·m−2s−1 for 15 days. Under these conditions, it was possible to remove 89.97% of carbonaceous organic matter, 86.50% of nitrogen, and 30.64% of phosphorus. The scaled-up photobioreactor operated with similar performance.

scholarly journals Can light emitting diode-based road studs improve vehicle control in curves at night? A driving simulator study

2016 ◽  
Vol 50 (2) ◽  
pp. 266-281 ◽  
Author(s):  
A Shahar ◽  
R Brémond ◽  
C Villa
Keyword(s):  
Driving Simulator ◽  
Light Emitting Diode ◽  
Lateral Position ◽  
Vehicle Control ◽  
Night Time ◽  
Light Emitting ◽  
Road Lighting ◽  
Country Road ◽  
Simulator Study ◽  
Subjective Level

Road delineation treatments enhance the ability of drivers to control their vehicle safely on winding roads. A simulator experiment compared night-time driving on a country road under three conditions: on an unlit road, on a road illuminated on curves by typical road luminaires, and on a road with an active lane delineation application, where self-luminous road studs are turned on to outline the lane and road edges as the driver approaches and passes the curves. The unlit condition induces greater lateral position variability and longer crossovers relative to the studs condition, demonstrating better lateral vehicle control in the latter. The luminaires condition induce greater lateral position variability in left curves, and longer crossovers in right curves, relative to the studs condition, which also demonstrates a better lateral vehicle control in the studs condition. At a subjective level, the participants perceived both the studs condition and the luminaires condition as safer, more comfortable and allowing better control than the unlit road. It was concluded that the tested application enhanced the ability of drivers to control the virtual car, as compared to an unlit road or road lighting.

Comparison Research of Street Lamps: Characteristic Parameters and Lighting Performance of Light-Emitting Diodes, High Pressure Sodium Lamps and Ceramic Discharge Metal Halide Lamps

2012 ◽  
Vol 229-231 ◽  
pp. 2610-2614
Author(s):  
Min Li ◽  
Qiu Yi Han ◽  
Wei Li ◽  
Shui Jun Shi ◽  
Hao Jun Zhang ◽  
...  
Keyword(s):  
High Pressure ◽  
Light Emitting Diodes ◽  
Metal Halide ◽  
Laboratory Measurements ◽  
Characteristic Parameters ◽  
Light Emitting ◽  
Road Lighting ◽  
Comparison Research ◽  
Color Rendering ◽  
Metal Halide Lamps

As a rapid developing solid state lighting, light-emitting diodes (LEDs) have great potential in application of road lighting, but their performance evaluation in a long term are still lacked. In situ and laboratory measurements were conducted for the purpose of comparing the characteristic parameters and lighting performance of three kinds of street lamps: LEDs, high pressure sodium (HPS) lamps and ceramic discharge metal halide (CDM) lamps. The results of laboratory measurements in 2000 hours show the three kinds of lamps have almost the same initial luminaire efficacy, which lead to the average road illuminance is proportion to the lamp power. The results of road illuminance distribution measurements in 3000 hours show LEDs have better color rendering index, longitudinal uniformity of illuminance, and maintenance of road illuminance than HPS and CDM lamps.

Precise Luminous Flux and Color Control of Dimmable Red-Green-Blue Light-Emitting Diode Systems

2021 ◽  
pp. 1-1
Author(s):  
Cheuk Ping Germaine Wong ◽  
Albert T.L. Lee ◽  
Kerui Li ◽  
Siew Chong Tan ◽  
Ron Hui
Keyword(s):  
Blue Light ◽  
Light Emitting Diode ◽  
Luminous Flux ◽  
Light Emitting ◽  
Color Control

Analysis of Modified Current Controller and its Implementation in Automotive LED

2017 ◽  
Vol 6 (04) ◽  
pp. 01-06
Author(s):  
Prof. Bhushan Thakre, Dr. R.M Thakre
Keyword(s):  
Supply Voltage ◽  
Light Emitting Diode ◽  
Control Voltage ◽  
Process Technology ◽  
Light Emitting ◽  
Led Lighting ◽  
Current Controller ◽  
Dimming Control ◽  
Simulation Purpose ◽  
The One

A novel highly dimmable current controller which is a linear one is employed in the application of low power automotive is discussed here. Light Emitting Diode is the one which drives current that is linearly controlled to decrease the intensity of LED to limit the destruction of the LED and improve its reliability. Although many dimming techniques for LED lighting are available, our proposed method outperforms the existing methods in terms of power consumption and the no. of transistors used in the proposed design. This emits 100mA and decrease the LED current which is going linearly based on the theory of dimming control voltage. Toggling of LED is avoided finally in comparison with the existing system. This circuit is developed in 0.18μm process technology and Cadence ADE with Spectre is employed for simulation purpose. The proposed method utilizes a maximum power of 392.85 mW when the supply voltage is 4V and the control voltage is 4V at the temperature of 27oC.

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