In urban lighting, the road lighting system is an integral part of high-quality road lighting can not only reduce the night traffic safety problems, but also to add bright colors to the city's night scene. At present, most of the street light sources in urban lighting systems still use high-pressure sodium lamps, so there is a problem of "three low" with low luminous efficiency, low color temperature and low color rendering index.
With the development of LED lighting in recent years, the problem of "three lows" is expected to be solved and urban lighting of higher quality can be obtained at the same time. At present, the promotion of urban road lighting technology is the development of lighting the main trend of the lighting industry, here we have a simple discussion for your reference program.
1. Capacitive compensation energy-saving program
The current application of more programs is the capacitance compensation, add inductive ballasts in the light bulb, react with other substances to produce glowing gas, play a role in energy saving. Electronic ballasts are characterized by excellent performance in terms of energy saving, and their own energy consumption is very low, only 5% of the ordinary lamp power, while having a high power factor, can greatly improve the efficiency of the grid.
Regulator energy-saving program
The traditional energy-saving voltage regulator scheme mainly consists of two modes - voltage regulator and thyristor voltage regulator, but both of these voltage regulator models are more or less there are different shortcomings. Therefore, the new voltage regulation method came into being, the modulation principle is: to collect environmental data system operation information, calculate the actual output power of the circuit, by adjusting the voltage control of street light brightness, and ultimately achieve with less power resources Dimming task. The program uses less electricity to meet the lighting needs, maintaining the stability of the city street lamp voltage.
3.LED streetlight program
Compared with the traditional light source, LED light source with high luminous efficiency, color temperature adjustable, high color rendering index, smaller, less heat and many other advantages, as the fourth generation of light source has become the mainstream of the future lighting products. LED street lamps in the arrangement, the series LED lights in the form of simple, easy to connect the circuit, current and brightness.
However, this connection also has some shortcomings, such as low reliability, the driver output voltage is higher, the higher requirements of the bypass series form. The form of the LED lamp is currently used in a wider range of its high reliability, cross-array form to ensure high efficiency. However, the design process of the LED lamp driver in the form of a circuit is tedious. During the normal operation, the current of the LED lamp driver must both be current-flow.
LED street lights in the drive power settings also need special attention, the current LED lights have AC power supply and solar LED in two forms, including the advantages of solar LED display for smaller loads, less interference and so on. LED driver power supply is usually able to convert the AC voltage into DC voltage, while paying attention to the current matching. In the context of a small number of street lights, the operation and design of the driving power supply is relatively easy. When there is a large number of street lights, the feedback control of the driving power supply should be strengthened.
4.LED street lamp quality evaluation
From the perspective of users of road lighting, the most essential duty of road lighting is to serve road users at night, which is also the basic starting point for builders to plan, design and implement road lighting projects. According to the description of the standard values for lighting in motor vehicle lane, rendezvous area, sidewalk and non-motorized lane in "Urban Road Lighting Design Standard" (CJJ45-2015), it can be objectively evaluated whether the lighting effect of the designed lamp is up to standard.
4.1 LED road lighting problems
Currently led to the user doubts about LED lighting products mainly from two aspects:
(1) lighting project quality control deficiencies.
In the new road lighting projects, often appear to sacrifice the quality of road lighting in exchange for the maximization of energy saving issues. The reason why this problem is masked is mainly due to the fact that only the level of illumination and uniformity of the motor vehicle lane is considered during the completion of acceptance, while the quality of the actual lighting is neglected. Many problems caused by this kind of problems ensue, such as disability glare, non-compliance of the environment, and non-compliance of vertical illumination of sidewalks.
(2) glare problem.
Compared with the traditional lighting, LED light-emitting mechanism will cause the user's visual inductive decline, accompanied by uncomfortable glare and other issues, so that the standard can be achieved by the traditional lamps are difficult to achieve, which has become the current number of users Contradiction LED street lamp reason.
4.2 LED lights with light problems
(1) vertical illumination problem.
Because of the LED light source in the light distribution design process is often replaced by point light source, easy to achieve accurate distribution of light distribution, making the light inside and outside the vehicle lane difference is obvious, which in the light utilization and illumination uniformity are reflected in the LED lighting source Excellent performance.
However, considering the illumination of sidewalks outside the motor vehicle lane and face recognition, such a bright and light source light distribution is not easy to meet the requirements. On the contrary, the traditional lamps are widely distributed in the horizontal and vertical directions of the road, and the distribution has no distinctive area division and can reach the place where the lighting is not originally designed at the beginning of the design. Therefore, the area of the sidewalk can be easily illuminated Easier to achieve face recognition.
(2) Inductive problems.
On smog day nights, the road illuminated by conventional sodium lamps may provide a better inducement because the right amount of light intensity distribution at larger vertical angles may be more distant than the smaller vertical angular distribution of LEDs Find its existence, thus identifying the linear features of the road. LED lights in the large vertical angle of light cut off too sharp, so even in the case of high road brightness, visual induction is also very small.
(3) uncomfortable glare problem.
Caused by uncomfortable glare Mainly due to the observation point of view, the observation distance and the choice of the brightness of the lamp surface. In terms of street lamps, both the viewing angle and viewing distance can not be changed, only the brightness of the lamp surface to choose from. As the surface brightness of high-power LED chips up to 107cd / m2, resulting in LED street lamps with different viewing angles in the lens surface brightness of 105-106cd / m2, far higher than the brightness of high-pressure sodium lamp, so in a short distance observation Under, LED lamps are more likely to cause uncomfortable glare.
A famous lighting company institute of technology, a joint study showed that LED glare can cause pedestrian and non-motor vehicle drivers miscarriage of justice, but due to motor vehicle drivers usually observe the distance, resulting in glare The problem will not have much impact.
The main problem stems from the LED lights with light, but this is not a natural defect LED light source. The precise optical properties of LEDs provide many options for the lighting design industry, one of which is to fully meet all of the road lighting indicators. The current problems are merely a contradiction caused by the manufacturer's commercial drive and the user's energy-saving drive phenomenon. LED street lamps to achieve road lighting energy saving, but one-sided emphasis on energy saving will bring other aspects of the problem.
In short, the road lighting quality standards is a comprehensive evaluation system, the unilateral pursuit of energy-saving lighting will inevitably lead to the loss of lighting quality, if the policy and construction parties deliberately emphasize energy conservation, then the quality of lighting issues will not be a reasonable solution;
Many LED street lamp manufacturer's lack of understanding of their products and applications, led blindly meet or even misleading the concept of construction side is also a major obstacle LED lighting industry. Therefore, LED road lighting is still a long way to go, as a LED lighting-related practitioners, we will always be on the road.