Overview of important technologies and specifications of high-performance LED street lighting systems

Energy conservation and environmental protection are the main trends. As the LED lighting industry is booming, a large number of technology companies have invested in this emerging industry. Due to the failure to set standards for the reliability of LED lighting performance in a timely manner, a large number of products failed to pass the test and ended up with serious light decay. This is because there is no design theoretical research as a pillar for inspection, which has caused users to be suspicious and delayed the opportunity for industry development. Here, we would like to briefly discuss the important technical indicators and specifications of high-performance LED street lights from multiple components to lighting systems for reference.

1.) Key technical indicators for luminous efficiency of LED chips and packaging components:

LED chip & packaging component key technologies, American and Japanese manufacturers have already achieved mass production with luminous efficiency exceeding 100~120 lm/W, surpassing the traditional highest efficiency HID light source (luminous efficiency 90~110 lm/W), and the illumination of lamps has been increased to ≧60 lm/W, meeting the requirements of long road lighting life, low light decay, average illumination of 25~40Lux in line with international standards, and energy saving of 50~80%.

2.) LED luminous efficiency VS temperature rise and life specifications Key technical indicators:

According to the LED data released by CREE or Osram, the chip PN junction operating temperature Tj < 85℃ can ensure a service life of 50,000 hours, and the temperature rise from the chip PN junction to its own heat conducting sheet (Tjs) is ΔT = 6~15℃. In addition, the LED light efficiency is inversely proportional to the operating temperature. Every 10℃ increase will lead to 5~8% light decay and half the life, which is far from the general propaganda that LED can work at 100℃ and have a life of more than 100,000 hours.

3.) Key technical indicators of heat transfer and heat dissipation of LED street light system VS ambient temperature:

The operating temperature of the lighting system shall not be higher than 85-10=75℃. The ITRI LED road lighting demonstration lighting specification in Taiwan stipulates that the ambient temperature of the durability test is 60℃. Therefore, the temperature rise of the street lamp heat dissipation system must be less than ΔT≦15℃. Taking the 150W LED street lamp of Xinyuansheng Technology Company in Taiwan as an example, the heat transfer heat dissipation system temperature rise test is as low as ΔT≦12~15℃, and its thermal resistance value Tr=0.08~0.1℃/W is calculated. The temperature rise test of the general design system ΔT≒30~40℃, and its thermal resistance value Tr=0.2~0.26℃/W, the life will be shortened by 2 times and the light decay will be more than 15%. In addition, the temperature rise of the heat dissipation system of the 350W LED lamp can still reach ΔT=15℃, and the thermal resistance value Tr=0.04℃/W is a high-quality product.

4.) Key technologies of heat transfer and heat dissipation methods for LED street light systems:

The heat transfer and cooling method of electronic equipment is suitable for low-power and low-level natural cooling methods. At present, the temperature rise of MR16/PAR30 from 3~100W products has reached 30~40℃. If the natural cooling method is still used for design exceeding 100~250W, a large amount of aluminum alloy materials must be consumed to increase the heat conduction and super large heat exchange area, and the volume weight varies from 15~30Kg. The cost of aluminum alloy materials alone will increase by 30~70 US dollars. If high-end products such as computer CPUs are used instead, active forced cooling methods that are 10 times faster than natural cooling are used. The high-efficiency military-grade micro fan has a guaranteed life of 50,000 hours and IP65 waterproof and dustproof level. The temperature rise of the lighting system is as low as ΔT≦12~15℃, which is more than 20℃ lower than the natural cooling method. The life will be increased by 2 times and the light efficiency brightness will increase by more than 15%.

5.) LED street light system reliability, durability and environmental adaptability performance test indicators:

The general product design does not take into account the dust protection system. It is necessary to completely prevent sandstorms and gravity dust from accumulating on the heat dissipation structure facing the ceiling, resulting in heat accumulation that cannot be dissipated, LED light decay and overheating and burning. Xinyuansheng Technology Co., Ltd. can design a heat dissipation structure facing the ground to completely solve the problem. It must still work normally under the high temperature of 60℃ desert for a long time. Other salt spray resistance tests, etc., after outdoor testing for 15,000 Hr., the light decay is <10% in good condition. The optical design of trunk road lighting meets the world's national standards. A 10-meter-high lamp pole must evenly illuminate a 40-meter-long banner road surface, solving the difficult optical lens design and meeting the requirements of a height-to-width ratio of 1:4.

The core wick technology module is lightweight and does not need to rely on the lamp housing as a heat sink, so the outer shape of the lamp can be changed arbitrarily to achieve the aesthetic characteristics of each city.