LED Street Lighting reference field installation in Banff
The Canadian town of Banff, located in a UNESCO World Heritage Center national park, launched a pilot project to convert its street lighting to LEDs.
This case study highlights an LED Street Lighting solution, using Golden DRAGON ARGUS LEDs, to meet the requirements for street lighting according to the IESNA and RP-8-00.
The joined reference design is implemented between the LED Light for you Certified Partners. Technical competencies from optical, thermal and electronic are brought together for this street lighting solution. Luminaire manufacturers can use this reference design as a basis for their own luminaire development for quick and easy solution of their own.
The circular beam shape from Golden DRAGON ARGUS LED directs the light to the target area in combination with a secondary reflector system from Alux-Luxar, based on the sophisticated reflector material from Alanod. All LEDs are mounted on a metal core PCB (MCPCB) T-Clad® from Bergquist for a quick heat transfer to the heat sink. SIIX Corp. provides an effective solution for soldering the LEDs to the MCPCB. A secondary circular MCPCB from Laird allows for illuminination within the fixture, providing a decorative element to the luminiare. The heat sink from Coolermaster provides the required thermal mass for heat dissipation as well as a mechanical attachment point. Finally the driving of the LEDs is solved with a PFC stage from STMicoelectronics and LED drivers from Supertex.
LED Fixture (Foreground) with existing metal halide fixture (background)
LED fixture installation in picturesque town of Banff, Canada, used to illuminate the street and sidewalk. The top cap of the fixture is also illuminated as a decorative element to resemble the tree line in the background.
Homogeneous light distribution on the road
The combined intensity distribution pattern and efficient drive scheme allows for a direct replacement of the incombinante 100W ceramic metal halide lamp. The radiation characteristics of the lens of the LED (angle 140°), coupled with a reflector provides an optimized beam pattern on the both the street and adjoining sidewalk. The implemented 54 x 1.3 Watt LEDs with a pole height of 5m fulfills the street lighting RP-8-00 for a local roadway of intermediate type (5 lx average illuminance).
Effective cooling and strong mechanical attachement of the LEDs is accomplished using Bergquist's T-Clad® MCPCB, which consists of the circuit layer, dielectric layer and base layer. This stackup allows heat to be to be transfered effectively from the LED, through the thin dielectric layer to the Aluminium base layer. A similar principle is incorporated into Laird's MCPCB disc used to illuminate the interior cavity of the fixture.
Close up view of light engine with Golden DRAGON ARGUS LED and Alux-Luxar reflector
Cooler Master thermal modeling considers the impact of factors such as power dissipation (hereby 70W), mechanical dimension, type of heat sink, and airflow requirements. The heat sink also serves as the mechanical structure to which the LED and reflector assembly and mounting brackets are attached to. The light engine is completely enclosed in a water resistant sealed housing to avoid moisture penetration.
A power factor correction (PFC) stage from STMicroelectronics, which is required for street lighting applications, provides 400V DC to three additional driver boards. These driver boards are HV9910CRB11 demo boards developed by Supertex, each capable of driving a string of LEDs (at 400mA) with a total power of up to 70W. One driver powers 27 white LEDs (24 for main light and 3 for interior illumination), the second drivers 24 white LEDs and a third drives the 6 yellow LEDs.
- Street Lighting
- Outdoor Lighting
- Radiation pattern of LEDs and reflector directs light effectively to the target area (street and sidewalk)
- Full cutoff fixture reduces light pollution and light trespass to surrounding buildings
- Long and predictable service intervals
>> reduced maintenance cost - Reliability and long lifetime
>> increased road safety - Dimming
>> adjusted to specific ambient light levels - Mixing yellow and white LEDs
>> flexibility in color temperature and CRI - No problem with hot ignition
>> quick turn on / off without time delay - LED contains no polluting materials
>> easy lamp recycling - Higher light output even at lower temperatures
Optical solutions
Optical manufacturer, Optical Engineering, Optical and light consulting / Light Architecture
Thermal solutions
Thermal management engineering, Heatsink engineering and manufacturing, Thermal management substrates, Thermal interface materials
Electronic solutions
Electronic and Controls Engineering, Electronic Manufacturing Services (EMS), IC Driver manufacturers, Driver circuit supplier
- OSRAM – LED: GOLDEN DRAGON ARGUS
- Alanod – Reflector material
- Alux-Luxar – LED reflector customized
- Bergquist – MCPCB: T-Clad®
- Laird – MCPCB
- Coolermaster – Heatsink
- Supertex – LED driver: HV9910
- STMicroelectronics – PFC / MOS FET / Diode: EVAL6562-80 / STD5NM50
- SIIX Corp. – EMS: Selective Soldering Process:
Photo Credits:
OSRAM Opto Semiconductors
Project Credits:
OSRAM Opto Semiconductors
Alanod
Alux-Luxar
The Bergquist Company
Cooler Master Co., Ltd.
Laird Technologies
Supertex Inc.
STMicroelectronics N.V.
SIIX Corp.
