Comparison of technical parameters of LED light source street lamps

According to the provisions of "Urban Road Lighting Design Standard" CJJ45-2006, high-pressure sodium lamps, metal halide lamps, compact or thin-tube fluorescent lamps can be used as light sources for road lighting. As a new light source of this century, LED has begun to be used on the road. What technical parameters of new light source street lamps and traditional street lamps are worth promoting and improving?

1. The purpose of urban road lighting

Create a good visual environment for drivers of various vehicles and pedestrians, so as to ensure traffic safety, improve transportation efficiency, facilitate people's lives, reduce crime rates and beautify the urban environment.

2. Comparison of characteristics of light sources for road lighting

The light source used for road lighting should have good lighting effects and meet the requirements of economy and energy saving. The main characteristics of light sources for road lighting are compared in Table 1.

3. Choice of light source

According to the "Urban Road Lighting Design Standard" and the application of new LED light sources, the author believes that the light source of street lamps should be selected as follows:

(1) Expressways, trunk roads, secondary trunk roads and branch roads should use high-pressure sodium lamps or LED lamps;

(2) High-pressure sodium lamps, low-power metal halide lamps or LED lamps are used on mixed traffic roads of motor vehicles and pedestrians in residential areas;

(3) Metal halide lamps or LED lamps can be used in motor vehicle traffic roads such as city centers and commercial centers where color recognition requirements are high;

(4) Low-power metal halide lamps, narrow-diameter fluorescent lamps, compact fluorescent lamps or LED lamps may be used on pedestrian streets in commercial areas, pedestrian roads in residential areas, and sidewalks on both sides of motor vehicle traffic roads.

4. Basic requirements for street lamps

The basic requirements for lighting fixtures should be safety, practicality, energy saving, and environmental protection. If they are economical, reliable, beautiful, and easy to install and maintain, they will be perfect fixtures. As for street lamps, since they are used outdoors for a long time and the environmental conditions are relatively harsh, in addition to the optical performance meeting the requirements of relevant standards and specifications, there are also higher requirements in terms of mechanical strength, dustproof, waterproof, corrosion resistance, heat resistance, electrical safety performance, electromagnetic compatibility, quality, installation, maintenance and shape.

5. Road lighting evaluation indicators

1. The evaluation indicators of motor vehicle traffic road lighting should be the average road surface brightness (or average road surface illuminance), total road surface brightness uniformity and longitudinal uniformity (or road surface lighting uniformity), glare limitation, ambient ratio and induction.

2. Pedestrian road lighting should be evaluated based on average road surface illumination, minimum road surface illumination and vertical illumination.

6. Road lighting design principles

It is necessary to achieve good lighting effects while also embodying the principles of safety and reliability, advanced technology, economic rationality, energy conservation, environmental protection, and easy maintenance.

7. Road lighting design details

1. The design of road lighting must meet the requirements of current relevant standards in terms of road surface brightness (or illumination) level, brightness (or illumination) uniformity, glare limitation, etc. The lighting facilities should also have good induction.

2. It is both economical and meets energy-saving standards.

3. Safe and reliable operation.

4. Easy to maintain and manage.

5. Advanced technology.

8. Visual Information Required by Drivers

One of the main functions of road lighting is to provide drivers with a good visual environment at night so that they can obtain a series of visual information:

1. Are there any obstacles or pedestrians on the road and where are they located?

2. Road width, alignment and structure.

3. Whether there are special places (intersections, etc.) on the road and their locations.

4. The condition of the road surface, whether there are any defects or damage and where they are located.

5. Are there other vehicles using the road at the same time? Their types and operating speeds.

6. Condition of road peripheral facilities.

7. Accurate "no obstacle" information.

9. Illumination and brightness of road surface

The illuminance at a certain point on the road surface is only related to the photometric characteristics of the lamp itself and the geometric position of the point relative to the lamp, while the road surface brightness is related to the above factors as well as the reflective properties of the road surface itself. What the human eye perceives is the road surface brightness, not the illuminance.

10. Classification of Inducibility

Road lighting facilities should provide good induction, which can be divided into two categories:

1. Visual guidance: Through the road guidance auxiliary facilities, such as the center line of the road surface, curbs, road signs, emergency road barriers, etc., the driver can clearly know his position and the direction of the road ahead.

2. Optical induction: The arrangement of light poles and lamps, the style of lamps, the color of lights or the changes in their intensity can indicate changes in the direction of the road or the approach to special places such as intersections.

11. Energy saving of road lighting

Realizing energy conservation in road lighting is a long-term task for energy conservation and emission reduction. Energy conservation standards are listed as mandatory provisions in the Urban Road Lighting Design Standards. Energy conservation can be achieved by taking measures in the design stage, operation period, and management. For example, in the design stage, lighting standard values ​​can be reasonably selected, high-efficiency lighting devices can be selected, and lighting design can be optimized.

12. On-site measurement of road lighting

In addition to the photometric test of road lighting fixtures in the laboratory, after the road lighting project is completed and put into operation, it is usually necessary to conduct on-site measurements of road brightness and illumination to determine whether the actual lighting effect of the road meets the original design requirements, providing a basis for more economical and reasonable designs in the future. The measurement after the lighting facilities have been in operation for a period of time is to study the light decay of the lamps due to dust accumulation and long-term use, and to calculate the maintenance coefficient.

13. Road lighting methods

There are five basic arrangements for deep lighting:

1. Single-sided arrangement;

2. Staggered arrangement;

3. Symmetrical layout;

4. Horizontal cable suspension arrangement;

5. Central symmetrical layout;

Through the comparison of the above related technical parameters and the details of the parameters of the relevant information, we can see that the new light source has shown a huge potential market space. In today's street lighting era, new light sources that comply with national industrial policies will bring a new revolution to the street lighting market.