Solar Powered Lighting for Overhead Highway Signs
The purpose of the research is to design and develop a low cost solar powered lighting system for overhead highway signs with a view to improving night visibility especially under poor driving conditions, and enhance highway safety. Two lighting systems have been researched, developed and tested: one system employs light emitting diode (LED) technology and the other uses compact fluorescent lamp (CFL) technology. The commercial CFL lights are ac powered and for dc operation with photo-voltaic energy, a new inverter design has been implemented. The inverter efficiency is better than 95% and the total harmonic distortion (THD) is less than 15%. The design incorporates SLA (Sealed Lead Acid) batteries for energy storage. The inverter is essential when hybrid operation (solar as well as ac line) is desired. For stand-alone solar application, it has been shown that the CFL lights can be directly operated from dc source and thus eliminate the inverter to minimize power losses. Further, a new dc operated ballast configuration was also investigated for CFL lighting to increase its luminous efficacy. The LED system employs pulse-width modulation technique controlled by a micro-controller for its operation. Both the systems incorporate a power management controller to adjust the lighting effect to compensate for weather conditions for days with inadequate solar charging. The two lighting systems have been deployed to illuminate two signs (Memphis and Remington Exit) on Interstate 40 East at the Remington exit. The CFL technology was used for the Remington Exit sign with a lighting area of 50-60 sq ft. This report presents the design and development of the two systems, their outdoor deployment results, and recommendations for future research.
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Supplemental Notes:
- This research was sponsored by the U.S. Department of Transportation, University Transportation Centers Program.
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Corporate Authors:
Mack-Blackwell Transportation Center
University of Arkansas, 4190 Bell Engineering Center
Fayetteville, AR United States 72701Arkansas State Highway and Transportation Department
State Highway Department Building, 10324 Interstate 30
Little Rock, AR United States 72209Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC United States 20590Research and Innovative Technology Administration
1200 New Jersey Avenue, SE
Washington, DC United States 20590 -
Authors:
- Patangia, Hirak C
- Publication Date: 2009
Language
- English
Media Info
- Media Type: Web
- Edition: Final Report
- Features: Figures; Photos; References;
- Pagination: 39p
Subject/Index Terms
- TRT Terms: Field tests; Fluorescent lamps; Illuminated traffic signs; Light emitting diodes; Lighting; Night visibility; Overhead traffic signs; Solar energy
- Uncontrolled Terms: Future research
- Subject Areas: Highways; Operations and Traffic Management; I85: Safety Devices used in Transport Infrastructure;
Filing Info
- Accession Number: 01135875
- Record Type: Publication
- Report/Paper Numbers: MBTC 2096/3007
- Contract Numbers: MBTC 2096 (Grant)
- Files: UTC, TRIS, USDOT, STATEDOT
- Created Date: Jul 24 2009 4:03PM