Abstract
Content
- Introduction
- 1. The principle of operation of autonomous street lighting
- 2. Calculation of external lighting installations of an urban area
- 2.1 Lighting engineering calculation of outdoor lighting of the playground at the house
- 2.2 Roadway lighting
- Conclusion
- References
Introduction
The street lighting systems considered in this paper, like all other lighting systems in general, have one very important the peculiarity is the use of electricity in the dark, when the use of solar energy is impossible. It is for this reason, most lighting systems, for maximum efficiency, in addition to solar panels, have a wind generator. This allows you to use for generating electricity from two independent renewable sources at once – sun and wind. Thus, subject to the use of the drive energy of sufficient capacity, the problem of the variability of electricity generation, and ensuring the operation of the lighting system in the dark is solved.
Preliminary studies of the use of solar and wind energy for lighting systems, it was possible to conclude that wind generators they are rarely used in populated areas.
Comparison of the sun and wind as RES, allowed us to conclude that, that solar energy currently has a number of significant advantages over wind. The main thing of them is that, of course, the reserves of wind energy in Russia are huge, but they are mainly located on flat terrain, in the coastal waters of the seas, in northern latitudes, etc. It is there, at a considerable distance from settlements, that the maximum return will be from wind farms, and the infrasound noise from they will not affect people's health (sleep disturbance, irritation, etc.).
1. The principle of operation of autonomous street lighting
Autonomous street lighting allows you to dramatically reduce the cost of supplying the supply cable, organizing a substation, an electricity metering unit, obtaining permits and approvals in various instances.
The principle of operation of street lighting on solar panels is to convert the energy of sunlight through solar cells into electric current. Then the electric energy enters the battery, where it accumulates. The battery feeds the lamp, usually LED, and, thus, night lighting of the territory occurs. LED lamps are the most economical light sources. Switching on and off the lamp at the right time, as well as monitoring the battery charging is carried out by a special control unit. The solar-powered autonomous street lighting system can also be equipped with additional functions. For example, you can implement light level control. In the "standby mode" the lamp will shine for 20-40% depending on its power, and when any movement is detected in the controlled area, the luminous flux increases to 100%. Thus you can extend the battery discharge time
The correct functionality of the lighting complex, as well as its cost, will depend on how much the power of solar panels and battery capacity are correctly selected . The greater the power of the solar panel and the battery capacity, the longer the lamp will shine, but the cost of the entire installation will be much more significant.
The principle of operation of a solar lamp is based on the conversion of solar energy into electrical energy.
The autonomous lamp consists :
- Solar panel. Depending on the power of the lamp, there may be different sizes.
- Charge controller. Monitors the panel voltage, charges the batteries and turns the lamps on and off.
- Battery. The battery capacity depends on the power of the lamps and the duration of illumination.
- The lamp of the lamp. It is made in the form of a set of LEDs, which allows you to minimize the consumption of electrical energy with high-quality illumination of the terrain.
Additionally, depending on the brand and design, such lamps have power on/off buttons, the lights are equipped with motion sensors.
During the daytime, the sun's rays fall on the upper part of the lamp, on which the solar panel is located. This panel supplies voltage to the controller, which in turn charges the internal battery of the lamp. As soon as the voltage on the panel drops below the level set in the controller (for him it will mean the onset of night), the lamp will turn on and shine all night, depending on the selected mode of operation of the lamp. The motion sensor is needed just for the above modes of operation.
The advantages of choosing autonomous street lighting are obvious. Firstly, there is no dependence on local electric networks, with their interruptions in the supply of electricity. Secondly, it is not always possible to draw a line from a transformer substation to a pole. Speaking of carrying out power lines to poles, it is also necessary to take into account the cost of the project to connect the network to street lights. Also, the installation of the presented lanterns does not need to be coordinated with the local energy company.
2. Calculation of external lighting installations of an urban area
2.1. Lighting engineering calculation of outdoor lighting of the playground at the house
It is planned to illuminate a playground of 150 square meters. It is necessary to install a certain number of lights.
Let's choose the option of a street lamp Ziverd Front 30
The calculation is carried out according to the formula: L = E*S*N*K / (F*X)
where L - is the desired number of lighting fixtures.
E – illumination (lux). From the SNiP we take the number 10 lux.
S – the area, which by condition is equal to 150 m2.
N – the coefficient of uneven illumination. In fact, this is the ratio of maximum illumination to minimum. For different types of lamps, its different values are set: 1.15 for incandescent lamps, 1.1 – fluorescent, 1 – LED
K is a coefficient that takes into account the decrease in the brightness of the lamp due to contamination, dust or worn glass during prolonged operation. The value depends on many factors, ranging from the type of lamps and ending with the degree of dustiness of the space. Suppose that the townhouse located in a clean area, then K will be equal to: 1.5 for incandescent lamps, 1.4 for gas discharge, 1 for LED. The value of this coefficient is another reason to choose the LED option. After all, the final amount will be smaller, which means that the installation costs are lower.
F – the luminous flux of one lamp. This is a numerical expression of the amount of light emitted, measured in Lumens (lm). It is usually indicated in the technical documentation for the device (you can multiply the lamp power by the luminosity coefficient). In our case, the indicator is specified by the manufacturer and is equal to 3735 lm.
X is a coefficient that is determined based on the reflectivity of objects and buildings on the territory of the site being developed. To search for it, we can refer to the same SNIP. Suppose that only the facade of the house decorated with pink silicate bricks will interfere with the uniformity of the distribution of light. In this case, "X" = 0.3.
We turn to the calculation of lighting with a street lamp for a playground:L = 10*150*1*1 / (3735*0,3) = 1,34.
Thus, it is possible to install one lamp of the specified power, or two of lower power.
2.2 Roadway lighting
Calculate the required distance between lamps with a height of 8 m, on the roadway with a width of 6 m. The lamp model used is an autonomous street type SSL3-50W
The distance between the luminaires (the pitch of the luminaires) is calculated by the formula: Ф=L*K*π/η
where:
L – normalized coverage brightness coefficient;
К – stock ratio;
η – the parameter of using the luminous flux.
The calculations will also require special data from the tables of luminaire utilization coefficients. Tables can be found in the technical literature.
According to the lighting standards GOST R55706-2013 "OUTDOOR UTILITARIAN lighting Classification and norms" is a section of a local street of category B class B2 (Residential development in the central part of the city).
The calculation is carried out according to the Web application International Lighting Corporation galad.ru .
To do this, we choose a similar lamp GALAD Victoria LED-40-SB/K50 (740/RAL9023/0/ORS/GEN1).
We determine the parameters of the lighting system .
Conclusion
To illuminate the roadway with a width of 6 m, an autonomous street lamp of the SSL3-50W type was selected [2], the pitch of the supports was 38.3 m . The lamp contains a charge controller, the battery is 3.2V / 18Ah Life PO4. The lamp power is 50 watts. The solar panel is polycrystalline 5V, 35W. Advantages of choosing autonomous street lighting [3]: there is no dependence on local electrical networks, it is not always possible to draw a line from a transformer substation to a pole. Speaking of carrying out power lines to poles, it is also necessary to take into account the cost of the project to connect the network to street lights. Also, the installation of the presented lanterns does not need to be coordinated with the local energy company.
References
- Правила устройства электроустановок. 7-е изд. М.: Кнорус, 2015. 491 с.
- Автономный уличный LED светильник SSL3-50W [Электронный ресурс] - Режим доступа. - URL:https://ledster.com.ua/ulichnie_led_solar_fonari/ssl3_50w.html
- Столков, А.С. Выпускная квалификационная работа бакалавра [Текст] : Разработка системы автономного освещения для набережной города Барнаула / А. С. Столков, И. А. Бахтина: Изд-во Алт. гос. техн. ун-та им. И. И. Ползунова, 2016. – 56 с.