Analysis of the advantages and disadvantages of traditional street lamps and LED street lamps

　　1. Introduction  the characteristics and performance of sodium lamps

　　When the bulb is started, an electric string is generated between the electrodes at both ends of the arc tube. Due  the high temperature of the arc, the sodium amalgam in the tube is heated and evaporated in mercury vapor and sodium vapor. The electrons emitted by the cathode hit the discharge material during the movement  the anode. There are ams  obtain energy  generate ionization excitation, and then return from the excited state  the stable state; or from the ionized state  the excited state, and then return  the ground state infinitely looping, the excess energy is released in the form of light radiation, which produces light .

　　High temperature of lamps: The luminescence of high-pressure sodium lamps belongs  the principle of burning and luminescence, and the temperature of the bulb is very high when it is working; generally speaking, it must reach 1000 degrees or more  maintain the stability of the arc; Some, the temperature ranges from tens  hundreds of degrees. If re-ignited in a stable state (10 minutes later), the surface temperature of the glass bulb is averaged, that is, the average glass bulb temperature is about 200 degrees Celsius, and the temperature will exceed 300 ~400 degrees Celsius.

　　Voltage: High-pressure sodium lamp has a strong dependence on voltage, and the change of power supply voltage should not be greater than ±5%. The tube pressure drop, power and luminous flux of high-pressure sodium lamp change with the change of power supply voltage, which is larger than other gas discharge lamps; when power supply voltage When it rises, due  the increase of the tube pressure drop, it is easy  cause the lamp  brake and go out; when the power supply voltage decreases, the luminous flux will decrease and the light color will become worse.

　　Radiation, pollution

　　The sodium lamp needs  be equipped with a glass cover, and the installation height should be above 6m  prevent ultraviolet rays from burning the eyes or skin, and  prevent people from accidentally uching the lamp and causing burns; after the bulb is broken, it should be properly handled in time, because the sodium lamp bulb contains mercury ,  prevent mercury pollution.

　　Low color rendering index

　　The light emitted by the high-pressure sodium lamp has a strong spectrum at 589nm and its vicinity, so the light color is yellow, the color temperature is only 2000-2100K, and the color rendering is poor. Generally, the color rendering index is only 20-25.

　　Luminous intensity is not high

　　50~60LM/W

　　High maintenance cost

　　Because the average life of the bulb of the high-pressure sodium lamp is about one and a half years, and the rectifier is about two years, it will cause the user  frequently purchase the corresponding accessories for maintenance and replacement; and the luminous efficiency of the sodium lamp decays quickly, even if the lamp is not broken, the luminous efficiency Insufficient, it also needs  be replaced with a new bulb.

　　application

　　After the high-pressure sodium lamp is extinguished, it needs  be cooled for a period of time. After the mercury pressure in the tube decreases, it can be started again. Therefore, this type of lamp cannot be used in places that require rapid lighting.

　　Safety facr

　　Because the high-pressure sodium lamp itself consumes a lot of power, and the voltage is very high when starting, the voltage is above 1000V when starting, or the inert gas inside cannot be excited, so the matching cable should be one level higher than usual. The number of branch lamps should not be o much, o much will cause the cable overload temperature  be higher and hot, which may cause the cable  accelerate the aging, in the light of the short circuit of the wire, and in the worst case, it may cause the distribution box  catch fire and cause a fire. The second is that the bulb of the sodium lamp may burst. The temperature of the broken glass bulb is still high. If the glass bulb falls on a combustible object without protection, it may ignite and cause a fire.

　　trend

　　As early as 2009, with the advancement of technology, the European Union planned  phase out halogen lamps in the region year by year and replace them with more advanced LED technology. Halogen bulbs, also known as tungsten halogen bulbs, are a type of incandescent lamp, and are most commonly used in aumobile headlights and rear lights, as well as in public places such as homes, offices, and office buildings. However, since halogen lamps are rated as D-level in terms of energy efficiency, which is the lowest level in EU guidelines, halogen lamps may no longer be in circulation anywhere in the EU after September 1, 2018.

　　2. Introduction  the characteristics and performance of LED street lights and high pole lights

　　Road lighting is closely related  people’s production and life. With the acceleration of my country’s urbanization process, LED street lights have gradually adopted advantages such as directional light emission, low power consumption, good driving characteristics, fast response speed, high earthquake resistance, long service life, and environmental protection. In people’s vision, it has become the world's most energy-saving light source of a new generation with the advantage of replacing traditional light sources. Therefore, LED street lights will become the best choice for road lighting energy-saving transformation.

　　The difference between LED street lights and conventional street lights is that the LED light source adopts low-voltage DC power supply and high-efficiency white light synthesized by blue LED and yellow. It has the unique advantages of high efficiency, safety, energy saving, environmental protection, long life, fast response speed, and high color rendering index. Widely used in roads. The outer cover can be made, the high temperature resistance can reach 135 degrees, and the low temperature resistance can reach -45 degrees.

　　advantage:

　　1. Its own characteristics-the one-way light, no light diffusion,  ensure the efficiency of light.

　　2. The LED street lamp has a unique secondary optical design, which irradiates the light of the LED street lamp  the area that needs  be illuminated, and further improves the light efficiency  achieve the purpose of energy saving.

　　3. 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 luminous efficiency is theoretical, in fact, the luminous efficiency of high-pressure sodium lamps above 250W is higher than that of LED lamps. ).

　　4. The light color rendering of LED street lamps is much 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 lamps is above 75. From the perspective of visual psychology, the same brightness can be achieved. The average illuminance of LED street lamps can be It is more than 20% lower than high pressure sodium lamp.

　　5. The light decay is small, the light decay in a year is less than 3%, and it can still meet the road requirements after 10 years of use, while the high-pressure sodium lamp has a large decay, which has dropped by more than 30% in about a year. Therefore, the design of the power of the LED street lamp Can be lower than high-pressure sodium lamps.

　　6. The LED street lamp has an aumatic control energy-saving device, which can achieve the greatest possible reduction in power and energy saving under the condition of meeting the lighting requirements at different times. It can realize computer dimming, time period control, light control, temperature control, aumatic inspection and other humanized functions.

　　7. Long life: It can be used for more than 50,000 hours, and it can realize the ideal state of maintenance-free for 5-10 years.