What is LED street light
LED street lights refer to street lights made from LED lighting fixtures, which have unique advantages such as high efficiency, safety, energy conservation, environmental protection, long service life, fast response speed, and high color rendering index. They are of great significance for energy conservation in urban lighting.
Road lighting is an important component of urban lighting, and traditional street lights are often used. High pressure sodium lamps emit light 360 degrees, which results in significant energy waste due to their high light loss. Currently, the global environment is deteriorating day by day, and countries are developing clean energy. With the rapid growth of the national economy, the contradiction between energy supply and demand in China has become increasingly prominent, and there is a serious shortage of electricity supply. Energy conservation is an urgent problem that needs to be solved. Therefore, developing new efficient, energy-saving, long-life, high color rendering index, and environmentally friendly LED street lights is of great significance for urban lighting energy conservation.
Road lighting is closely related to people's production and life. With the acceleration of urbanization in China, LED street lights have gradually entered people's vision with advantages such as directional lighting, low power consumption, good driving characteristics, fast response speed, high seismic resistance, long service life, and green environmental protection. They have become the world's most energy-efficient new generation of light sources to replace traditional light sources. Therefore, LED street lights will become the best choice for energy-saving transformation of road lighting.
Advantages of LED street lights
- Its inherent characteristics - the unidirectionality of light, no diffusion of light, ensuring illumination efficiency.
- LED street lights have a unique secondary optical design, which illuminates the required lighting area with the light of LED street lights, further improving lighting efficiency and achieving energy-saving goals.
- The LED has reached 110-130lm/W, and there is still a lot of room for development, with a theoretical value of 360lm/W. The luminous efficiency of high-pressure sodium lamps increases with the increase of power, therefore, the overall luminous efficiency of LED street lamps is stronger than that of high-pressure sodium lamps; The overall light efficiency is theoretical, but in reality, high-pressure sodium lamps with a power of 250W or more have higher light efficiency than LED lamps.
- The color rendering performance of LED street lights is much higher than that of high-pressure sodium lights. The color rendering index of high-pressure sodium lights is only about 23, while the color rendering index of LED street lights is above 75. From a visual and psychological perspective, achieving the same brightness, the average illuminance of LED street lights can be reduced by more than 20% compared to high-pressure sodium lights.
- The light attenuation is small, with less than 3% in one year, and it still meets the road requirements after 10 years of use. However, the high pressure sodium light has a large attenuation, which has decreased by more than 30% in about one year. Therefore, LED street lights can be designed with lower power consumption than high pressure sodium lights.
- LED street lights have automatic control energy-saving devices, which can achieve maximum power reduction and save electricity while meeting lighting requirements at different time periods. It can achieve user-friendly functions such as computer dimming, time division control, light control, temperature control, and automatic inspection.
- Long lifespan: Can be used for over 50000 hours, providing a three-year quality guarantee. The drawback is that the lifespan of the power supply cannot be guaranteed.
- High light efficiency: Using chips with a power output of ≥ 100LM can save more than 75% energy compared to traditional high-pressure sodium lamps.
- Easy installation: No need to bury cables or rectifiers, directly connect the installation to the lamp post or nest the light source into the original lamp
- Excellent heat dissipation control: In summer, the temperature is controlled below 45 degrees Celsius and passive heat dissipation is adopted, resulting in insufficient heat dissipation guarantee in summer.
- Reliable quality: All circuit power supplies are made of high-quality components, and each LED has a separate overcurrent protection, so there is no need to worry about damage.
- Uniform color of light: Without adding a lens, uniform color of light is not sacrificed to improve brightness, thus ensuring uniform color of light without aperture.
- LEDs do not contain harmful metal mercury and will not pose a threat to the environment when discarded.
- The power of a single LED is low. To achieve high power, multiple devices need to be used in parallel.
- Low color rendering. The color displayed under LED illumination is not as real as that of incandescent lamps, which needs to be analyzed from the perspective of spectral distribution and is a technical issue.
- Spot. Due to defects in the manufacturing process of white LED and fitting errors with reflective cups or lenses, it is easy to cause the problem of "yellow circles".
- The issue of LED illumination uniformity. If secondary optical design is not carried out, the illumination of LED is relatively concentrated, so it is necessary to carry out secondary optical design to make its light intensity distribution map form a bat shape.
- The issue of LED light attenuation. Compared to low-power LEDs, high-power LED street lights have much better light attenuation. But low-power LEDs emit very little heat. However, high-power LEDs have a problem that cannot be solved by heat dissipation, and the brightness will significantly decrease after heating, so the power cannot be increased. The largest Spark LED street light sold in the market is 360W.
Disadvantages of LED street lights
Key points for selecting LED street lights
luminous efficiency
The technology is becoming increasingly mature, and high-power LED light sources can meet the needs of general street lights. The light efficiency of a typical high-pressure sodium lamp is 100LM/W, while the commonly used high-power LED is 50-60LM/W. Using foreign LED chips can achieve 80LM/W. The higher the luminous efficiency, the better the energy-saving effect, which is also one of the most important indicators for choosing LED street lights. However, there is no clear provision for this in the LED standards, so careful confirmation is necessary when purchasing LED street lights.
Light attenuation
Some businesses, in order to reduce costs, use hundreds of 0.5W low-power LEDs. However, the light attenuation of this low-power LED is very serious, with a lifespan of only 1000 hours when the light attenuation reaches 80%. Therefore, as street lights that require long-term use, it is absolutely not allowed to use this type of low-power LED. Choosing high-power LED (generally referring to 30W or above) will result in much better light attenuation.
Self weight issue
Due to the high technological content and complex composition of LED street lights, some high-power lamp holders will have a much heavier weight than ordinary high-pressure sodium lamps, so higher requirements are placed on the corresponding supporting materials. However, some LED street light manufacturers have tried their best to reduce the weight of LED lamp heads, from about 30 kilograms per head to over 10 kilograms. The weight reduction still has a further downward trend.
Heat dissipation
LED, as a semiconductor component, loses its illumination significance when its chip is reduced to 30% of the initial luminous flux due to temperature influence, which means its lifespan is over. In theory, the lifespan of high-power LED street lights is between 30000 to 50000 hours, but the important prerequisite is good heat dissipation. It is worth mentioning that some domestic manufacturers have adopted the world's leading needle shaped heat dissipation technology.
Inspection standards for LED street lights
- Develop inspection standards for the production of street lights in our company based on the following reference standards
- GB/T191 Packaging, Storage and Transportation Illustrated Markings (GB/T191-2008, ISO780:1997, MOD) 2. GB/T2900.65 Electrical Terminology Lighting (GB/T2900.65-2004, IEC60050-845:1987, MOD)
- GB7000.1-2007 Luminaires Part 1: General Requirements and Tests (GB7000.1-2007, IEC60598-1:2003, IDT)
- GB7000.5-2005 Safety Requirements for Road and Street Lighting Fixtures (GB7000.5-2005, IEC60598-1:3:2002, IDT)
- GB/T9468 General Requirements for Photometric Measurement of Luminaire Distribution
- GB17625.1 Electromagnetic Compatibility Limits Harmonic Current Emission Limits (Equipment Input Current ≤ 16A per phase)
- GB/T17626.5 Electromagnetic Compatibility Testing and Measurement Techniques Surge (Impact) Immunity Test Electromagnetic Compatibility Testing and Measurement Techniques Wave
- Surge (Impact) Immunity Test (GB17626.5-2008, IEC61000-4-5:2005, IDT)
- GB17743 Limits and Measurement Methods for Radio Disturbance Characteristics of Electrical Lighting and Similar Equipment (GB17743-2007, CISPR15:2005, IDT)
- GB19510.1 Lamp Control Devices Part 1: General and Safety Requirements (GB19510.1-2004, IEC61347-1:2003, IDT)
- CJJ45-2006 Urban Road Lighting Design Standard
- SJ/T11364 Requirements for Pollution Control Identification of Electronic Information Products
- IEC60838-2-2 Miscellaneous lamp holders Part 2-2 Special requirements for connectors for LED modules
- IEC61347-2-13 Lamp Control Devices Part 2-13 LED Module Control Devices Safety Requirements
- IEC62031 Safety requirements for LED modules for general lighting
- IEC62471 Photobiological safety of lamps and lamp systems
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