Metro LED lighting design

1 Introduction

In recent years. With the rapid development of the national economy, the number of cars in China has increased sharply, road congestion has become increasingly serious, and underground cities (metro stations) have been built in major cities. To alleviate traffic congestion. The subway runs underground all year round and has high requirements for lighting. Not only requires power saving, high brightness, and long life. Uninterrupted lighting must also be guaranteed.

At present, commonly used incandescent lamps, fluorescent lamps, high-pressure sodium lamps, etc. are all powered by the AC grid. The best-designed AC grid is also inevitably subject to power outages. To ensure uninterrupted lighting in the ground. An emergency lighting power source consisting of a rectifier, a battery, and an inverter must usually be installed. When the grid is normally powered, the AC power is converted to DC by the rectifier and charged to the battery; when the grid is interrupted. The battery turns the direct current into alternating current through the inverter to supply power to the lighting fixture. The cost of such an uninterrupted lighting system is high, and at the same time, it has undergone many changes. Power consumption is also large.

In recent years, semiconductor lighting lamps (LEDs) powered by DC power supplies have been rapidly developed. These lamps consume 90% less energy than incandescent lamps. At the same power, LEDs have a luminous intensity higher than that of ordinary fluorescent lamps and high-pressure sodium lamps by more than 40%. And the life of LED lights can reach 10 million hours. The color rendering index can reach more than 80, far higher than the high pressure sodium lamp. Due to the constant current supply of DC, it is impossible for the LED lamp to strobe.

therefore. It has become the best green lighting fixture. The use of LED lights in subway stations not only saves a lot of electricity and a lot of copper cables. It also saves a lot of maintenance costs. It also ensures the quality of the lighting. Aiming at the problems existing in the current subway lighting system. It provides a novel structure and low cost. Long service life and good power saving effect. Highly reliable metro lighting solutions.

2 lighting classification and distribution

Metro stations (underground rail transit) are usually divided into two floors: the station floor and the platform floor, and their corresponding electromechanical equipment is usually arranged at both ends of the station (A and B). Station lighting points: equipment area lighting, public area work lighting, public area power saving lighting, cable interlayer lighting, guiding sign lighting, according to the load level: primary load, secondary load, tertiary load. The primary load mainly includes: accident lighting, class II guiding sign lighting, three types of guiding sign lighting, four types of guiding sign lighting, public area working lighting, power saving lighting; secondary load is mainly equipment area working lighting and a kind of guiding sign Lighting; three-stage load mainly has advertising lighting. The incoming power of the accident lighting power supply room is taken from the two low-voltage busbars of the substation, and the battery is used as the backup power source.

3 lighting power distribution design

3.1 In order to facilitate operation and management, a lighting distribution room is set up at the station platform and the station floor at both ends of the station. The upper and lower two distribution rooms are generally aligned, which facilitates the management of the electrical equipment of the floor and the upper and lower cables. Laying. The public lighting distribution box is centrally located in the lighting distribution room for easy control.

3.2 Types of lighting and control methods: Lighting is divided into general lighting, emergency lighting, induced lighting, advertising lighting and security lighting. Centralized management of public lighting, unified control. The computer room and office lighting are controlled locally. In the early design of the Beijing subway, part of the lighting was a constant light that continued to work after the train was stopped, called power-saving lighting. Because the meaning of power-saving lighting can not correctly express its lighting properties, some cities do not use the word subway, but collectively referred to as general lighting.

3.3 The lighting of the platform and the hall floor is mainly composed of general lighting and I emergency lighting. Each section of the platform and station lighting is a two-way lighting power supply, divided into 6~8 branches, cross-distribution. After the peak of the operation, some of the branches can be stopped to save lighting power. The attached room can be powered by a separate loop. After the night train is out of service, the general lighting is turned off, and the station lighting is illuminated by emergency lighting.

3.4 Emergency lighting: In order to ensure the smooth and safe evacuation of passengers in the event of a station failure, a 220V battery pack is installed at the underground station, and the emergency lighting is supplied in a state where both AC power sources are out of pressure. The underground railway emergency lighting is mostly incandescent. Under normal circumstances, it is powered by AC power. When the AC power is cut off, it automatically switches to the battery pack. Here, 3W white LED light can be used, which is normally powered by AC 220V power supply, and automatically switches to battery pack power supply when AC power is cut off. The 3W white LED lamp has the same illumination as the 60W incandescent lamp, but the electric power is only about 1/15 of that of the incandescent lamp, and the life is about 10 times that of the incandescent lamp. Emergency lighting at the station platform, station hall and the population is a common light, there is no centralized control, the station attached room and equipment room is controlled locally.

3.5 The single-phase socket of the station attached to the station and the single-phase safety socket set every 30m on the platform and the station floor are powered by separate circuits and equipped with a leakage protection switch.

3.6 Interval illumination: The single-line tunnel is set on the left wall of the driving direction. It is divided into work lighting and emergency lighting. A 3W white LED light is set every 5~6m. The two kinds of lighting are arranged in phase, and the working and emergency lighting are changed. The DC screen of the electric station is directly powered, and the interval work lighting is controlled by the substation.

3.7 Safety lighting: The safety lighting under the platform board adopts 36V safety voltage, and the lighting transformer is installed in the lighting distribution room.

3.8 Illumination requirements of different places in the subway: The lighting stress should be practical and easy to maintain, and should be matched with the architectural form according to the requirements of different occasions. In order to ensure the normal function of the station and the section, the illumination standard of the underground station is shown in Table 2.

3.9 Metro stations are mainly based on energy-saving fluorescent lamps (including fluorescent lamps). After the appearance of low-loss, high-efficiency LED lamps, LED lamps should be used as the main lighting lamps.

4 section lighting and lighting

4.1 The tunnel section between metro stations is called the interval. Interval lighting is the tunnel lighting of the subway (underground rail transit). The interval illumination is divided into work lighting and emergency lighting. The lighting fixtures are arranged on the left upper wall of the driving direction, and a lighting fixture is arranged every 5 to 6 m. The working lighting and the emergency lighting are arranged in phase, and an emergency lighting is set every two working lights, that is, an emergency lighting is set every 15m. The working lighting is powered by a three-phase AC power supply. The emergency lighting is normally powered by a single-phase AC power supply. When the AC power fails, the station's step-down substation automatically switches to the battery pack. A working lighting box and a knife lighting box are arranged every interval of about 120m. Each lighting box has two circuits, each with a lighting fixture of about 60m in the direction of the tunnel.

4.2 Interval lighting fixtures should be waterproof, dustproof and corrosion resistant. The lamps should be adapted to the environment of damp, water and poor ventilation in the subway tunnel. It requires good sealing performance (protection performance reaches IP65) and good heat dissipation. Do not allow water to enter when the lamp is cleaned and rinsed. The structure of the luminaire is simple, easy to install, and easy to operate when repairing and replacing the light source. The luminaire should have good anti-shock performance and ensure the light source has a high service life under the condition of subway vibration. The light efficiency of the luminaire should be greater than 60 lm / W. The luminaire should have a certain shading performance to avoid affecting the driver's vision. The light source can be a 3W white LED lamp. When using energy-saving fluorescent light source, emergency lighting requires AC and DC, and instantaneous start, LED lighting is the best choice. Because when emergency lighting, the substation sends out 220V DC power; in normal lighting, the substation sends 220V AC power. The LED luminaire has a power of only 3W, which is comparable to the luminous flux of a 60W incandescent lamp. Moreover, the life of LED lamps is 50,000 hours, while the life of incandescent lamps is only 1000 hours. Through economic and technical comparison, the use of LED lamps can not only save a lot of energy, but also save operating and maintenance costs. Has a great advantage.

5 subway station lighting

5.1 Subway station lighting is divided into: station station hall, station platform, exit channel, stairs and office. Lighting brightness requirements are relatively high, generally using 40W of traditional fluorescent lighting. The lamps are densely packed and consume a lot of electricity. Under normal power supply conditions, 24 hours of uninterrupted lighting is required.

5.2 can use 12W white LED fluorescent lamp instead of traditional 40W fluorescent lamp. Not only can a large amount of power be saved, because the color rendering of the LED light source is high, and the lighting effect can be greatly improved. LED fluorescent lamps also have a much longer life than conventional fluorescent lamps, and can also save a lot of maintenance costs.

6LED lamps and traditional lamps and lanterns

7 conclusion

7.1 High energy saving rate: On average, there is more than 70% energy saving rate.

7.2 High lighting quality: LED color rendering is higher than traditional lighting fixtures, effectively improving the lighting quality in the subway.

7.3 Good safety: The working temperature of LED lamps is generally below 50 degrees, and there will be no danger such as fire.

7.4 Long life: LED lamps have a theoretical service life of 50,000 hours, and the measured service life has reached more than 5 years. Far more than all traditional lamps.