Rozprawy doktorskie na temat „LED STREETLIGHT”

Målet med arbetet var att undersöka hur enskilda gatlyktor skulle kunna utrustas med ljussensorteknik för att implementera automatisk dimring med syftet att sänka energianvändningen. Rapporter visar att väg- och gatubelysningen i Sverige stod för 626 GWh år 2016 samt att en stor del av ljuspunkterna fortfarande består av energikrävande högtrycksnatrium. Uppgifter visar även att energisnåla LED-armaturer blir alltmer förekommande som alternativ till högtryckslampor. Målet var att utveckla en prototyp för LED där funktionen bygger på att lysdioderna ska vara släckta när omgivningens ljusstyrka är hög och dynamisk dimras upp när omgivningens ljusstyrka minskar. Arbetet resulterade i en prototyp som fungerar tillfredsställande och efter uppsatta mål. Varje ljussensor läser in ett analogt mätvärde som tolkas av en mikrokontroller som sedan skickar en pulsbreddsmodulerad signal för styrning av lysdiodens belysningsnivå. Generellt visade arbetet att omfattande fortsatta studier behöver göras innan prototypen skulle kunna implementeras i verkligheten. Prototypen behöver även testas och kalibreras i utomhusmiljö med dagsljus.
The goal of this thesis was to investigate how individual streetlights could be equipped with light sensor technology to apply an automatic dimmer function with the purpose of reducing energy usage. Studies show that road and streetlights in Sweden accounted for 626 GWh during the year 2016 and that a large portion of the lights still consists of energy demanding high pressure sodium lamps. Reports also show that energy efficient LED is becoming more and more common as an alternative to high pressure lamps. The goal was to develop a prototype for LED lighting with the function to control the LED’s to be off when the surrounding light levels are high and to dynamically increase the output power when the surroundings light level go down. Each light sensor reads an analog value which is interpreted by a micro controller that sends a pulse width modulated signal to control the LED power output. The finished prototype worked satisfactory and according to the set goals of the thesis. Generally, the thesis showed that extensive research is needed before the prototype could be implemented in real life. The prototype also needs to be tested and calibrated in an outdoor environment with day light.

碩士
國立臺南大學
通訊工程研究所碩士班
99
In this paper, we proposed and designed the lens for light emitting diode (LED) street lights by optical designing software Trace Pro which provided a platform for us to comprehend how the rays go forward through lens and roadway simulation software dialux, where dialux software is used to assess the average dialux lighting and uniformity. Many LED street lamps used matrix array, which has many disadvantage like circuit design problems. We used multi-chip on lead frame, that is, single module high power LED (140W) package design, which can reduce size of streetlight, lessen the complexity for lens'' designing and reduce cost. We probe three kinds of lens to compare the light intensity far field angle and illumination. With the basis of optical design and LED lights can achieve high output efficiency until 0.857; high uniformity from 0.587 to 0.753, the average illumination from 19 lx to 21 lx and approach of batwing far field beam angle distribution can be achieved.

碩士
國立高雄應用科技大學
電機工程系博碩士班
103
Nowadays, with the environmental problems such as imminent exhaustion of fossil energy and increasingly serious global warming make the concept of environmental protection about energy conservation, and carbon emission reduction has been taken seriously, and many energy-saving systems have been proposed in various fields with the trend of energy conservation and carbon emission reduction. Furthermore, there are a lot of energy-saving technologies and patents of "road lighting", which are closely linked with people's daily life. In order to achieve the goal such as energy conservation and carbon emission reduction, those technologies and patents recommend reducing unnecessary power consumption by adjusting the brightness of streetlight. However, most of energy-saving streetlight systems merely focus on their energy-saving function, but neglect the optimal opportunity of using ofenergy-saving streetlight system, even ignore the problem that the energy-saving streetlight system may cause driver or road user to produce a phenomenon of visual fatigue, which may further lead to a traffic accident. In order to mitigate the foregoing disadvantages, this thesis constructs an LED streetlight control system that not only achieves energy conservation, carbon emission reduction, and environmental protection but also considers the traffic safety of drivers and road users. This system also makes the energy-saving streetlight work at the appropriate time to extend the life of streetlight and control system.

碩士
國立臺南大學
電機工程研究所
99
In this study, the street lamp with combining the multi-chip on board(MCOB) of LED light source and the freeform lens were proposed and simulated. In order to prevent two adjacent luminaries from generating strong brightness contrast on the road surface, i.e., the Zebra effect (repeated bright and dark regions). We design a freeform lens which can provide that the light intensity is good batwing distribution with light intensity about 3000 cd at the middle and 7000 cd at 60 deg. This indicates that a uniform and wide illumination area on whole road surface can be achieved. The uniformity values are 0.723, 0.866, and 0.875 for three basic placement of single-sided, zigzag, and opposite, respectively. These results suggest that the lamp installation numbers can be eliminated, and can be reduced thermal management.

碩士
中原大學
電機工程研究所
101
This thesis aims to combine photovoltaic (PV) charging system with an LLC resonant converter to achieve PV LED Street-lighting system without electrolytic capacitors. In control, the study using digital controller MCU to replace hardware components successfully attains digital control for maximum power point tracking (MPPT), battery management and lighting control. Based on the concept of energy saving, the system function and efficiency in study are considered from the PV panels through MPPT and battery charging management to the design of LLC converter. Finally, a prototype of 50W PV LED street-light without electrolytic capacitors is conducted to evaluate the LED output luminance and verify the LLC performance compared with the theoretical analysis.

In this work two Application of standalone PV system i.e. Solar LED Street light and water pumping system are carried out. These applications help in reducing the electric energy consumption and also enhance the rural electrification where grid is not present. In this thesis the techno economic analysis of different lighting schemes is carried out by using DIALux Software, which results in LED as an efficient light and then modeling of LED is discussed. The PFC buck converter based LED driver circuit is designed and implemented in this work. Solar Fed LED Street lighting system has different components i.e. SPV array, MPPT, dc-dc converter and battery unit. In this system MPPT plays a main role in battery charging so, the comparison of different MPPTs is carried out. In Solar Fed street lighting system which is modeled in Matlab-Simulink, the intensity of Street light is controlled from traffic hours to non traffic hours which results in saving the electricity consumption to half as compared to the non intensity controlled system. The PV hybrid street light is also implemented in this work. Solar oriented energy is an outstanding solution for rural regions where the grid isn't accessible. Most supported use of the SOLAR-PV System (SPV) is in water pumping system driven by DC/AC motors. Solar Powered DTC controlled Induction motor drive is superior to DC motor based system. The system includes MPPT (INC) with dc-dc boost converter, Voltage source inverter and a 3-phase induction motor drive. The DTC controlled techniques estimate the torque and flux, based on the instantaneous error of flux and torque the switching of VSI is generated. The reference speed is estimated by pump affinity law and DC link voltage regulation. The modeling of water pumping system is carried out using Matlab-Simulink.

碩士
國立臺灣科技大學
電機工程系
97
This thesis studies optical lens design of the LED luminaries for streetlights. In the same structure, only by replacing the luminaire lens to achieve different optical properties of the light distribution curve (short, medium, long distribution). First, the road lighting specifications has been surveyed as the performance index of the luminaire. Next, To define the final version of the institute to luminaire size by consolidating the structure of LED luminaire which had been marketed. Uniform optical properties of luminaire with the light distribution curve for the spindle, By combining the optical theorems and the angle of light beam energy distribution. The optical software, TracePro, is used to simulate luminous distribution of the luminaires. Then, executing the simulation of road lighting by using the software, DIALux, to assess the average illumination and uniformity. Simulatity results validate the theoretical analysis. The study can be employed in the optical lens design of the LED luminaries for streetlights in the future.

碩士
國立屏東科技大學
機械工程系所
97
This study reports on thermal analysis of the LED module and the cooling module of the high power LED streetlight module, respectively. By the simulation results compared with the experimental results, the thermal behavior of each module is observed. According to the simulation temperature values of each module, we proposed that various ways decreased the temperature values of the modules. In the study, we simulated temperature flied of each module by using ANSYS 8.0 software. By the boundary conditions of each module are defined that there are constant power and free convection. The analysis results of each module are solved by finite element method that there are temperature distribution, thermal flux, thermal gradient and heat flow. For experiment, we are operating each module for a long time in normal ambient temperature and atmosphere. When the temperature of each module is steady state, we measured the temperature of each module by using the thermography and the infra-red thermometer. The temperature results of each module shown, the results of the cooling module is made that the simulation value is 46.02 ℃ and the experimental value is 45.5 ℃. The results of the LED module is made that the simulation value is 101.33 ℃ and the experimental value is 100.7 ℃. After the simulation results are compared with the experimental results, The Error range of the LED module is within 2 % and the cooling module is within 3.5 %. For simulation temperature values, we proposed three ways that the temperature of each module is decrease. The better way is proposed by comparing the three ways. The temperature decrease rate of the LED module is about 3.45 % by the thickness of aluminum substrate increased 1 mm. The rate of the cooling module is about 6.2 % by installing the copper heat slug.

碩士
亞東技術學院
資訊與通訊工程研究所
103
LED is a semiconductor light emitting component which has many advantages such as high efficiency on illumination, low power consumption, high reliability, small size, and rapid turn-on. LED is applied in various electronics products. In recent decade, LED technology is now can be used as general lighting market. But LED is also constrained by its characteristics. Its lifetime and reliability can be lowered at over temperature operation. So the design of thermal solution is one of the most important issue when we develop a new LED lighting product. This study is to test performance change, such as correlated color temperature, luminous flux, and thermal gradient of a LED streetlight module by different heat dissipation configurations which set plate-fin and polymerizable liquid matrix thermal conductive material (thermal grease) as variants. Then we analyze the results from instruments by four pairs of experimental variants. Three factors are monitored in this research: (1) Light decay ratio (%) (2) Color shift during a period (3) Thermal gradient of the LED streetlight module. We summarize these factors and monitored results of thermal gradient differences. Furthermore, we test a LED streetlight module with long term burning condition and find out the module contains plate-fins and thermal grease performs better than other three configurations. The light decay ratio of the LED streetlight module is 87.6%, and the color shift is 2.5%. In order to verify the results of this thesis, we compare the results to other previous researches. The main factors make effect on thermal dissipation are the distance, height, length, thickness, and surface area of the plate-fins. An additional electrical fan can also help on the thermal issue of a LED streetlight module. This research focuses on how much can a LED streetlight module can be effected by the combination between plate-fins and thermal grease. With certain optical and thermal measurements, we investigate the physical changes by integrated sphere, T type thermocouple, and IR thermometer. By record of the data points on the LED streetlight module, we understand the trend of how the factors make effect on the performance of a LED streetlight module. Summarily, a well-designed thermal dissipation configuration can lower the average temperature on a LED streetlight module, then improves on the color shift effect and increases total efficiency of a LED streetlight. 【Keywords】：LED, Luminous Flux, CCT, Thermal dissipation analysis

碩士
國立臺南大學
電機工程學系碩博士班
102
We propose a novel, easy luminaire module of reflection type for streetlight. In general, many researchers use the transmission type design method to design the outdoor lighting, but in this master’s dissertation, we use the reflection type design method to the outdoor lighting The structure of the module is quadrilateral frustum shape that only use some plane to frame, it make the fabrication easier, cheaper than the other curved surface design. We put the LEDs on the side of the module that we can adjust the light distribution curve that could apply to the streetlight by vary the parameter of the module. In order to protect the luminaire module against the disturbance of external environmental factors, we must install a lamp screen on the luminaire module that isn’t change the most light distribution curve. Base on the Monte Carlo ray tracing method, the result satisfies to the standards of CIE and IESNA.

碩士
國立高雄應用科技大學
電機工程系博碩士班
104
Since energy conservation has been continuously concerned, the traditional lighting are being replaced by LED because of the advantages of LED, including low pollution, low energy consumption, and long life, etc. Therefore, high power LED is used as the light source to design street lighting in this thesis. The LED driver is built up by combining a buck-boost converter and a forward-flyback converter. Besides, a energy regenerative snuber is integrated into the driver circuit, which can improve the efficiency. Furthermore, the Primary-Side Sensing(PSS) technique and Quasi Resonance (QR) technique are employed to decrease circuit size and switching losses. A Digital Signal Processor (DSP) is used to integrate all related controls for the driver and the dimming circuit with the phase-shifted PWM method. Finally, the magnetic parameters of the driver are determined by using Taguchi method to optimize the system efficiency, and a prototype is produced and tested in laboratory. The test results are proposed and verify the feasibility of the system.

碩士
建國科技大學
電機工程系暨研究所
101
Abstract Traditional metal streetlights are too energy-consuming and require to work in the conditions of high temperature, therefore the service life is short and does not match the energy-saving trend of the times, they have been gradually replaced by white LED lights. According to the current white LED luminous efficacy(cool white: 254 lm/W, warm white: 216 lm/W), much larger than the metal lamps 60 lm/W luminous efficiency, white LED lights can save about 1/3 to 1/2 of energy. To achieve the energy-saving purpose, it is also required to take into account the efficiency and power factor problems when installed LED streetlights. According to the CNS LED Streetlight Standard CNS15233, which specifies the input power factor and overall conversion efficiency must be greater than 90%, this thesis proposes a new design of 200W high-performance LED streetlight drive circuits. It is composed of four parts of circuits: (1) power factor correction, (2) LLC resonant converter, (3) synchronous rectification, (4) constant current control circuit. The experimental results show that its power factor at full load under 220V input is up to 0.97, and the conversion efficiency of PFC stage is up to 97.8%; the maximum and full load conversion efficiencies of LLC resonant converter stage are as high as 96% and 95.5% respectively. The whole circuit conversion efficiency at full load is as high as 93%, power factor is also up to 0.99, either power factor or conversion efficiency is much superior to the values specified by the CNS Standards.

碩士
國立中正大學
光機電整合工程所
97
Owing to the Light Emitting Diode (LED) with the advantages of high brightness,less power consumption, long lifetime etc, it gradually becomes the development focus of lighting device in the future. In recent years, LEDs were aimed at the development of high power efficiency. However, such a situation always leads to an unavoidable waste-heat problem and causes an adverse effect on LED including the brightness decay and shortened lifetime. In dealing with heat-dissipation for highpower LED, most of methods rely on the heat dissipation plate, drilling holes, heat pipe, and adding isothermal vapor chamber, etc. The thermoelectric generators made of thermoelectric materials not only could solve the heat-dissipation problem of high power LED streetlights, but also effectively transform the waste heat to renewable electricity. Basing on the statement mentioned in the above, different structures using rapid heat-dissipation device collocating with thermoelectric generators were fabricated and applied on the high power LED streetlights to study the efficiency of rapid heat-dissipation and the electricity from transformed the waste-heat. Evidence indicated that the thermoelectric generator indeed acts the kernel technology for waste-heat transformed to renewable electricity. By integrating the thermoelectric generator with heat-conduction, heat-dissipation material, and heat-dissipation device, it not only could lead the 60W LED streetlight to reach the lowest LED junction temperature (48℃), but also obtain a renewable electricity (70.2mW) by transforming the waste-heat from high power LED streetlights.