LED Street Lighting Research Articles

Study on Evaluation of LED Lighting Glare in Pedestrian Zones

At present, there is no internationally accepted method of evaluation that converts discomfort glare in pedestrian zones into numerical form. While LED streetlights are rapidly coming into wide use, their light-emitting parts are often nonuniform in luminance compared with streetlights that employ HID lamps. This nonuniformity has been noted as a factor responsible for the emergence of glare. A subjective evaluation experiment was conducted with seven types of streetlights placed in an outdoor field that simulated a pedestrian zone. The streetlights used for the experiment were selected in consideration of the type of light source and the luminance uniformity of the light-emitting surfaces. The results showed that luminance-based photometric quantities are a better measure of discomfort glare than is the illuminance at the observer's eye for light sources with both uniform and nonuniform surfaces. Based on the experimental results, a new evaluation equation that converts discomfort glare in pedestrian zones is proposed.

Development of a Smart Solar-Powered LED Street Lighting System for Greener Community

The major objective of the study was to design and develop a Smart Solar-Powered LED Street Lighting System for a Greener Community. The project is different from conventional street lighting systems not only in the sense that it uses solar energy, but more importantly, it is also a stand alone device that provides for an efficient energy management program that ensures effective maintenance and reduced energy wastage due to malfunctioning lighting controls. In addition, it is much cheaper to fabricate and maintain as compared with its commercially available counterparts. One important feature of the project is that it automatically controls the brightness of the LED lamp depending on a particular time of day, especially in cases where full level illumination is not needed, thus reducing power consumption. It automatically activates and deactivates lighting depending on the hours whereby daylight is sensed, thus ensuring a continuous cycle of charging and discharging the storage battery for maximum efficiency. All of these functions are possible since the project uses a controller, allowing for variable settings of time activation as well as brightness level, depending on the preference of the end-users. The project functioned according to expectations, being a cheaper and environment-friendly alternative as compared with its commercially available counterparts. It also provided a cost-effective approach to managing street lighting systems in a wide variety of applications.

The Study for Saving Energy and Optimization of LED Street Light Heat Sink Design

LED lamps are characterized by high energy efficiency, high luminance, and long lifespans. However, the heat radiation problem caused by the extra high power shortens the lifespan and reduces the luminous efficiency of such lamps. This study introduced the development of a novel cooling fin structure for LED lamps and compared its performance with those of commercially available products. The objective of the design was to reduce the maximum temperature and temperature difference on the fin, the amount of aluminum required for fin manufacturing, and CO2emissions to save energy. The study employed the Taguchi method for experiment planning and used gray relational analysis and principal component analysis to determine the optimal parameter combination for cooling fins. The results showed that the maximum temperature on the fin surface dropped by 2.62°C in environments without forced convection, which indicated improved lighting efficiency. Furthermore, the amount of aluminum used per unit volume for fins was reduced by 15%, which effectively reduced CO2emissions during the manufacturing process.

基于自由曲面透镜的LED路灯配光优化设计

基于自由曲面透镜的LED路灯配光优化设计

스마트 LED 가로등을 위한 고속 전력선 통신 기반 자동제어 시스템

스마트 LED 가로등을 위한 고속 전력선 통신 기반 자동제어 시스템

유무선 원격제어장치를 이용한 LED 가로등 제어 시스템 구현

LED lighting control technique is one of the ongoing research areas for efficient management of LED lighting. In this paper, we design and implementation of LED street lighting remote control system which have a wired and wireless communication function for LED street lighting remote control. The implemented system can automatically dimming and individual(or consolidated) LED street lighting via RS-485/422 or Wi-Fi. In experimental results, the implemented remote control system was satisfactory for all of the desired functions.

독립형 태양광 발전을 이용한 효율적인 하이브리드 LED 가로등 조명관리 시스템 설계

In this paper, we propose a design for an efficient hybrid LED street lighting management system using standalone solar photovoltaic. The proposed efficient hybrid LED street lighting management system was composed of hybrid power conditioning system, gateways, LED street lights and a monitoring server. The hybrid power conditioning system was designed to charge produced power by solar photovoltaic panels in day time, and supply power to the LED street lights in night time. If there is insufficient power, the system was designed to operate using firm power, because the system utilizes photovoltaic power. A system control algorithm allied to the lighting management system, and experimented by being configured to the functions that are able to perform real-time monitoring and remote control through the lighting management system even when absent. In the result of the efficiency analysis of the hybrid lighting management system proposed in this paper, we were able to increase the energy efficiency compared to existing lighting control systems by reducing power consumption and electricity costs.

Development of LED Street Lighting Controller for Wind-Solar Hybrid Power System

This paper presents the design and implementation of a wind-solar hybrid power system for LED street lighting and an isolated power system. The proposed system consists of photovoltaic modules, a wind generator, a storage system (battery), LED lighting, and the controller, which can manage the power and system operation. This controller has the functions of maximum power point tracking (MPPT) for the wind and solar power, effective charging/discharging for the storage system, LED dimming control for saving energy, and remote data logging for monitoring the performance and maintenance. The proposed system was analyzed in regard to the operation status of the hybrid input power and the battery voltage using a PSIM simulation. In addition, the characteristics of the proposed system's output were analyzed through experimental verification. A prototype was also developed which uses 300(W) of wind power, 200(W) of solar power, 60(W) LED lighting, and a 24(V)/80(Ah) battery. The control system principles and design scheme of the hardware and software are presented.

Research and Design of Urban LED Street Lamp Wireless Management System

This article will Wave Mesh wireless ad-hoc network technology is applied to urban LED street lamp management system,with the single chip microcomputer 80C51F310 as the core,using real-time sensor testing environment brightness, and according to the brightness level of brightness, the LED street light illumination automatic adjustment;Aiming at the condition of the midnight staff less activity,using pyroelectric infrared human detection to control the brightness of the street lamp, the experimental data proved that energy saving effect is remarkable.The system safe and reliable, low cost,It has the advantages of single lamp remote monitoring,automatic dimming,electric energy measurement,alarm,fault diagnosis and fault location,etc.

LED Lights Wireless Intelligent Control System Based on LabVIEW

Because of LED lights require long-term monitor, the paper presents a remote intelligent control system based on LabVIEW. The system set up by the hardware and software simulation is completed. First collected working status and environmental parameters of the system by ZigBee wireless sensor network. Then transfer data to a remote monitoring center via WiFi. The functions including data real-time display, analysis and storage can be realized by LabVIEW. Using the information collected corresponding control can be adopted, the power and brightness of LED lights can be adjusted, etc. Experiments show that the system is stable, simple to operate, easy to wiring and suitable for the application of LED Street light at present.

Model predicting discomfort glare caused by LED road lights.

To model discomfort glare from LED road lighting, the effect of four key variables on perceived glare was explored. These variables were: the average glare source luminance (Lg), the background luminance (Lb), the solid angle of the glare source from the perspective of the viewer (ω) and the angle between the glare source and the line of sight (θ). Based on these four variables 72 different light conditions were simulated in a scaled experimental set-up. Participants were requested to judge the perceived discomfort glare of these light conditions using the deBoer rating scale. All four variables and some of their interactions had indeed a significant effect on the deBoer rating. Based on these findings, we developed a model, and tested its general applicability in various verification experiments, including laboratory conditions as well as real road conditions. This verification proved the validity of the model with a correlation between measured and predicted values as high as 0.87 and a residual deviation of about 1 unit on the deBoer rating scale. These results filled the gap in estimating discomfort glare of LED road lighting and clarified similarities of and differences in discomfort glare between LED and traditional light sources.

Modeling LED street lighting.

LED luminaires may deliver precise illumination patterns to control light pollution, comfort, visibility, and light utilization efficiency. Here, we provide simple equations to determine how the light distributes in the streets. In particular, we model the illuminance spatial distribution as a function of Cartesian coordinates on a floor, road, or street. The equations show explicit dependence on the luminary position (pole height and arm length), luminary angle (fixture tilt), and the angular intensity profile (radiation pattern) of the LED luminary. To achieve this, we propose two mathematical representations to model the sophisticated intensity profiles of LED luminaries. Furthermore, we model the light utilization efficiency, illumination uniformity, and veiling luminance of glare due to one or several LED streetlamps.

Design of Solar Energy Based Intelligent LED Street Lighting Controller

This paper aims to design an intelligent street lighting controller based on solar energy and LED. The controller can work in daytime mode, dusk mode based on detection of light intensity and photovoltaic voltage, and head into night mode after a certain period of time when in dusk mode. While in night mode, a dimming scheme is applied by introducing motion detection with passive infrared (PIR) sensors. The controller also integrates a ZigBee based WSN to report street lights status periodically and get instructions from the remote control center. Moreover, it can enable more efficient management and lower maintenance costs.

Two‐stage LED street lighting system based on a novel single‐stage AC/DC converter

A two-stage street lighting system is presented, where the front stage is a single-stage AC/DC converter based on the sepic circuit and flyback converter. Since the sepic circuit and flyback converter share a switching device, the costs of the system can be reduced, and the efficiency and reliability can be improved. At the same time, the switch operates in quasi-resonant state, which reduces the switching losses and enhances the efficiency. The second stage is a light-emitting diode constant current circuit, which achieves the constant current control by adopting boost circuit in peak current control mode. A 100 W prototype is presented, which confirms the correctness of the analysis, the front stage work in the soft-switching condition and the efficiency is up to 83% when the system is in full load condition.

The Design of LED Streetlights Controller with Light Control Long Time-Lapse

This paper focus on the features of half power saving in city road lighting LED retrofits , presences a light control and time-lapse switch LED lights control scheme, use photoresistor, 555 time base circuit and CD4060 binary counter, realized the control circuit design. The experimental results show that the proposed scheme in this paper is simple, practical and reliable.

An innovative wind–solar hybrid street light: development and early testing of a prototype

An innovative renewable hybrid microgeneration unit has been designed to be fully embedded into a dedicated LED street lighting system. The key feature of this new concept is the arrangement of a multiple Savonius vertical axis wind turbine into the structure itself of the post. A photovoltaic panel is integrated to contribute to power generation. The energy is collected by a power conversion equipment along with a storage device which ensures the lighting also during windless nights. The main application of this project is the standalone street lighting, but also a grid connected option is feasible, making the system compatible with microgrid concepts. Different Savonius rotors have been designed and characterized by wind tunnel tests. The adopted cylindrical geometry has shown a maximum power factor of 0.21. A dedicated safety equipment has been designed to prevent turbine over-speed by automatic stop in extreme wind condition. A full-scale prototype of the generator/lighting system has been installed. The experimental data acquisition is currently in progress to analyse on site performance and to allow energy simulations.

Handover method in visible light communication between the moving vehicle and multiple LED streetlights

When the moving vehicle is communicating with LED streetlights by visible light, the multiple LED streetlights signals will be selected or signal may be interrupted between adjacent streetlights. The method of receiving signal power (RSP) handover between the moving vehicle and multiple LED streetlights transmitters will be studied. Considering two cases, no power coverage and power overlap between adjacent streetlights. Hard RSP handover used in no power coverage model and soft RSP handover used in power overlap model. Simulation results show both RSP handover methods can protect the communication between the vehicle and LED streetlights and improve the stability of communication.

News: Connected LED street lights cut council costs

News: Connected LED street lights cut council costs

Correspondence: A proposed new LED road lighting concept

Correspondence: A proposed new LED road lighting concept

Power Management of LED Street Lighting System Based on FPGA

Power Management of LED Street Lighting System Based on FPGA