Application of LED in rail transit lighting system

Green lighting refers to the adoption of scientific lighting design, lighting products with high luminous efficiency, long life, safety and stable performance to improve and enhance people's work, study and life, so as to create an efficient, comfortable, safe, economical and beneficial The environment and fully reflects the lighting of modern civilization. At present, urban rail transit in Beijing generally adopts traditional lighting, and there are many deficiencies in the practical application of traditional lighting. In order to actively respond to the concept of low-carbon environmental protection and combine the characteristics of Beijing's urban rail transit itself, Beijing Rail transit carried out retrofit experiments with LED lighting fixtures replacing existing types of lamps. The application of LED can not only meet the requirements of green environmental protection, but also can solve the existing problems of lighting fixtures.

Current Status of Urban Urban Rail Transit Lighting in Beijing The types of lighting fixtures currently used in Beijing Urban Rail Transit stations include fluorescent lamps, metal halide lamps, and high-pressure sodium lamps. The variety of lighting fixtures is large and the power is large. It is neither convenient to purchase or maintain, nor is it energy-saving and environmentally friendly. Moreover, the lifespan of these lighting fixtures is generally lower than 10,000h, and some are even lower than 5000h. Currently, the operating voltage of the lighting fixtures in use is basically from the AC 220V. Due to the special distribution of the internal lighting of the urban rail transit, the distribution voltage is generally high, which makes the lamps easily damaged and the life cycle is shortened.

LED lighting characteristics LED or light emitting diode is an electronic device that can convert electrical energy into light energy. Its core part is the PN junction. In addition to its forward conduction, reverse cut-off, breakdown characteristics, under certain conditions, It also has luminescent properties, but light is only generated near the PN junction.

LED lighting has absolute advantages over traditional lighting, and is mainly embodied in eight areas.

(1) Voltage: The LED uses a low voltage power supply. The single voltage is between 1.9V and 4V, which is safer than using a high voltage power supply.

(2) Vibration resistance: LED is a solid state light source. Because of its particularity, it has the anti-vibration performance that other light source products cannot compare.

(3) Life: up to 50,000 h and above.

(4) Stability: Relatively small affected by ambient temperature.

(5) Response time: The response time of LED lighting is nanosecond, which is the fastest response time of all light sources.

(6)Energy saving and environmental protection: LED can save more than 60% to 80% of energy than traditional lamps, and does not contain harmful substances such as metallic mercury.

(7) Color: The bandwidth of the LED is narrow, and the color of the light is pure. Therefore, the color of the LED is much richer than that of other light sources and can more accurately reflect the authenticity of the object.

(8) Performance: LED light power conversion is close to 98%, so the light efficiency is high. After the experiment, the highest light efficiency has reached 161lm/W, which is the highest lighting efficiency product currently available.

LED lighting power supply uses a low voltage DC power supply. Therefore, LED lighting fixtures are equipped with AC/DC conversion and constant current driving power supply. This can effectively prevent damage to the lamps due to high voltage, thus improving the use of the lamps. life. LED lighting has a very short response time, can meet the requirements of emergency lighting and has a high luminous efficiency, making it the lowest power consumption under the same illumination standard, and can achieve the effect of energy saving and emission reduction. Because the LED is completely encapsulated in epoxy and made of non-toxic materials, it is very environmentally friendly and durable.

The application of LED in rail transit and the development requirements affecting the urban rail transit industry require strict control of costs and low consumption of environmental protection. In order to build modern rail transit, energy conservation and consumption reduction are taken as an important means to improve the overall networked operation and management capabilities, equipment and facility operations, and maintenance and implementation of refined management, so as to promote the overall coordinated and sustainable development of the capital transportation.

In accordance with the planning requirements of the urban rail transit industry, to strengthen energy management, mainly from the aspects of technological energy conservation and management of energy conservation to improve the efficiency of energy use, reduce energy consumption levels and stop energy waste.

At present, the trial application of LED lighting at some stations of Beijing urban rail transit is mainly reflected in the technical energy saving. The relevant technical data are collected through the station's experimental application to verify the practicality and economy of LED lighting for LED lighting in rail transit. The extensive application within provides a strong practical foundation.