China’s LED street lamp technology development status and problem analysis

Countries are actively promoting the implementation of energy-saving and emission-reduction projects, especially China’s LED street lamps are valued by LED street lamp manufacturers due to their huge business opportunities. Street lamps are an important part of urban lighting. Traditional street lamps often use high-pressure sodium lamps. The overall low light efficiency of high-pressure sodium lamps has caused a huge waste of energy. Street lamps are of great significance to urban lighting energy saving. the
Features of today’s LED street lights:
The difference between high-power LED street lights and conventional high-pressure sodium street lights is that the light source of high-power LED street lights is powered by low-voltage DC, and is a high-efficiency white light diode synthesized by GaN-based power blue LED and yellow phosphor. Light Emitting Diode (Light Emitting Diode, abbreviated as LED) is a high-efficiency solid-state light source that can emit light with weak electric energy based on the semiconductor PN junction. Under a certain forward bias voltage and injection current, the holes injected into the P region and the electrons injected into the N region diffuse to the effective The source region emits photons after radiative recombination, which directly converts electrical energy into light energy. the
As the light source of street lights, LED has many advantages compared with traditional street light sources. the
1. LED street lamp itself has light directivity, no light diffusion, ensuring light effect;
2. The LED street lamp has a unique secondary optical design, which irradiates the light of the LED street lamp to the area to be illuminated, that is, the road surface, which further improves the lighting efficiency and achieves the purpose of energy saving;
3. The light source efficiency of LED has reached 100lm/W at present, and there is still a lot of room for development. The theoretical value can reach 250lm/W. The luminous efficiency of high-pressure sodium lamps increases with the increase of power. Therefore, the overall luminous efficiency LED street lights are stronger than high pressure sodium lamps;
4. The light color rendering of LED street lights is higher than that of high-pressure sodium lamps. The color rendering index of high-pressure sodium lamps is only about 23, while the color rendering index of LED street lights can reach more than 75. From the perspective of visual psychology, to achieve the same brightness, the average illuminance of LED street lights can be It is more than 20% lower than high-pressure sodium lamps (refer to British road lighting standards); moreover, at the intermediate vision level, it is easier for the human eye to distinguish things in a high color temperature environment than in a low color temperature environment, avoiding the occurrence of certain dangerous states;
5. The light decay of LED street lamps is small, and the light decay of one year is less than 3%, and it still meets the road illumination requirements after 10 years of use. Therefore, the power design of LED street lamps can be lower than that of high-pressure sodium lamps;
6. LED street lights can be automatically dimmed, which can meet the lighting requirements of different periods, reduce the power as much as possible, and save energy;
7. LED is a low-voltage DC device, and the voltage to drive a single LED is a safe voltage, so it is a safer power supply than using a high-voltage power supply, especially suitable for public places. The characteristics of DC make LEDs especially suitable for combining with solar energy and wind power;
8. Each unit LED grain has only a small volume, so it can be prepared into devices of various shapes, and is suitable for variable and shock-prone environments;
9. Long life: the theoretical life can be used for more than 50,000 hours;
10. The LED can be switched frequently without worrying about its damage;
11. Easy installation: directly install the LED street lamp lamp holder on the light pole to replace the original sodium lamp lamp holder