Explore intelligent control systems for LED street lighting1

Today, the energy crisis is becoming increasingly apparent. In this context, people pay more and more attention to the problem of high energy consumption in the city coin road lighting system. Therefore, how to use an intelligent control system to achieve efficient control of street lighting to reduce energy consumption has become a key issue that people are currently paying attention to.

The intelligent lighting control system uses advanced electromagnetic voltage regulation and electronic induction technology to monitor and track the power supply in real time, automatically and smoothly adjust the voltage and current range of the circuit, and improve the extra power consumption caused by the unbalanced load in the lighting circuit. Power factor, reduce the operating temperature of lamps and lines, to achieve the purpose of optimizing power supply lighting control system.

Therefore, we first briefly introduce the lighting intelligent control system and the main control system in the urban street lighting intelligent control system, and then elaborate on the specific application of the intelligent control system in urban street lighting, in order to allow more people to recognize the city. The importance of street lighting intelligent control system.

Intelligent Lighting Control System

1. Features of lighting intelligent control system

Its main features are:

1) The system can control continuous dimming or switching of any loop.

2) Scene control: multiple different scenes can be set in advance, and fade in and fade out when the scene is switched.

3) Various sensors can be connected to automatically control the lights.

4) Motion sensor: Infrared detection of the human body to control the light; if a person comes, the light is on, and when a person leaves, the light is off (dark).

5) Light illuminance sensor: For some occasions, the indoor light can be adjusted according to the intensity of the outdoor light, such as the constant illuminance control of the school classroom.

6) Time control: In some occasions, the brightness can be adjusted with the commuting time.

7) Infrared remote control: The light can be controlled by hand-held infrared remote control.

8) System networking: It can be connected to the system, using the above-mentioned control means for comprehensive control or networking with the building intelligent control system. 9. The light can be controlled by sound, light, heat, human and animal movement detection.

2. The purpose of lighting intelligent control system

The intelligent lighting control system outputs an optimal lighting power to the lamps under the condition of ensuring that the lamps can work normally, which can reduce the lighting glare caused by overvoltage, make the light emitted by the lamps softer, and the lighting distribution more uniform. It can also greatly save power, and the power saving rate of the intelligent lighting control system can reach 20%-40%. The intelligent lighting control system can be used in lighting and hybrid circuits. It has strong adaptability and can work continuously and stably under various harsh grid environments and complex load conditions. At the same time, it will effectively prolong the life of lamps and reduce maintenance costs.

3. The principle of lighting intelligent control system

The voltage level varies around the world. Therefore, when designing various lamps, in order to meet their own normal start-up and light emission under different circumstances, the design voltage is generally lower than the standard phase voltage 220V; and the power system is often used to facilitate power transmission. Increase the transmission voltage, causing the actual working voltage of the lighting fixture to be too high. These excess voltages not only cannot make the lamps work more efficiently, but also have two major negative effects: wasting electric energy and shortening the life of the lamps.

Aiming at the fatal defect of the existing lighting circuit, Dr. Baowa DL series intelligent lighting energy-saving control system optimizes the input voltage of the power supply system by means of electromagnetic induction, adopts AC-AC direct conversion technology to adjust the voltage, and outputs the voltage to the lighting load. Design the optimal value of voltage for lamps, which not only saves electricity, but also prolongs the life of lamps, and also ensures the triple purpose of lighting standards.

According to the basic principle of electrician P=U2/R, set the electric current applied on the lamp。 The voltage is u, and the impedance of the light is set as a fixed-value resistor R, then the power it consumes under the original voltage UO is PO, and after the voltage is properly reduced to U1, the consumed power P1 will decrease with the square of the voltage. Its active power saving rate is expressed as: %=1 - (U1 /U0)2×100%

In the case of fluorescent tubes, sufficient rated voltage is required only at start-up to excite the phosphors and make the tube glow. Within the preset time, after the intelligent lighting control system senses that the power of the lamp tube has been fully utilized, it will automatically adjust the load voltage, and the lamp can be turned into the power-saving mode, and the intelligent lighting power-saving control system will enter the automatic online detection state at the same time . According to a large number of experimental results, it is shown that when the power supply voltage is reduced by 10%, the illuminance of fluorescent lamps is only reduced by about 7%, while the human eye's perception of light is a logarithmic relationship: that is, when the illuminance of light is reduced by 10%, the brightness of human visual perception is only 10%. Therefore, the slight change in illuminance caused by a reasonable reduction in the input power of lamps can hardly be felt by human eyes. The intelligent lighting control system has positive significance in prolonging the life of lamps and reducing maintenance costs.

4. The effect of lighting intelligent control system

1) Automatic control of lighting

The biggest feature of the system is the scene control. There can be multiple lighting circuits in the same room. After adjusting the brightness of each circuit to achieve a certain lighting atmosphere, it is called a scene; different scenes can be preset (to create different lighting environments), switch The fade in and fade out time of the scene makes the light change softly. Clock control, use the clock controller to make the light change according to the daily sunrise and sunset or regular time. Use various sensors and remote controllers to achieve automatic control of lights.

2) Beautify the environment

Indoor photos use scene changes to increase the artistic effect of the environment, produce a sense of three-dimensionality and layering, and create a comfortable environment, which is beneficial to people's physical and mental health and improves work efficiency.

3) Extend lamp life

The main factors affecting the life of lamps are overvoltage use and cold shock, which greatly reduce the life of lamps. LT series intelligent dimmer has the function of output voltage limiting protection: that is, when the grid voltage exceeds the rated voltage of 220V, the dimmer automatically adjusts the output within 220V. When the bulb is cold and connected to electricity, an inrush current of 5-10 times the rated current will be generated, which will greatly affect the life of the lamp. The intelligent dimming control system adopts slow opening and fade-in and fade-out dimming control, which can avoid the cold impact on the lamps and prolong the life of the lamps. The system can extend the lamp life by 2–4 times, which can save a lot of lamps and reduce the workload of replacing lamps.

4) Save energy

The brightness sensor is used to automatically adjust the intensity of the light to achieve energy-saving effects. Using a mobile sensor, when people enter the sensing area of the sensor, the light gradually rises, and when people leave the sensing area, the light gradually decreases or goes out, so that the lights of some corridors and corridors can be controlled to achieve the purpose of energy saving. For example: In order to save electricity, a restaurant replaced all corridor lights with 5W energy-saving lamps to reduce energy consumption, but the problem is that the comfort of energy-saving lights is very poor, and the illumination is reduced, which reduces the grade of the hotel. Motion sensor control is recommended.

5) Consistency of illuminance and illuminance

Using the illuminance sensor, the indoor light can be kept constant. For example: In a school classroom, it is required that the light intensity near the window and the wall are basically the same. Sensors can be installed at the places near the window and the wall. When the outdoor light is strong, the system will automatically weaken or turn off the light near the window. The sensor against the wall adjusts the brightness of the light against the wall; when the outdoor light becomes weak, the sensor will adjust the brightness of the light to the preset illuminance value according to the sensing signal. The luminous efficiency of new lamps will gradually decrease with the use of time, and the reflectivity of the wall of the new office building will attenuate with the use of time, so that the old and new will produce inconsistencies in illuminance. The control of the intelligent dimmer system can adjust the illuminance to achieve a relative Stable and energy saving.

6) Comprehensive control

The entire system can be monitored through the computer network, such as knowing the current working status of each lighting circuit; setting and modifying the scene; controlling the entire system and issuing a fault report when there is an emergency. It can be connected with the building's BA system or fire protection system, security system and other control systems through gateway interface and serial interface. LT-net intelligent lighting control system usually consists of dimming module, switching power module, scene control panel, sensor and programmer, It is composed of programming socket, PC monitoring machine and other components. By connecting the above modules with independent control functions to a computer data line, an independent lighting control system can be formed to realize various intelligent management and control of the lighting system. automatic control.

Intelligent Control System in Urban Street Lighting

1. Main control system

The main function of the main control system is to intelligently control the street lights, which can also be called the main control center. The main control system usually includes a monitoring center, data storage center, (uninterruptible) power supply, printout equipment, and monitoring equipment. The main control system is responsible for sending control instructions and setting instructions to the on-site terminal equipment, and executing these instructions through the on-site terminal equipment to realize intelligent control of street lights. It is worth mentioning that at least two servers should be equipped in the main control system, and the two servers are mutually backup (dual machine hot backup). At the same time, only one server is used to implement intelligent control work. If one of the servers fails, the other will take over its work at the first time to ensure the normal operation of the entire system.

2. Local control system

In the urban street lighting control system, the local control system usually has strong independence. The local control system usually consists of an RTU with a high independent working capability and its terminal equipment. In the intelligent lighting control system of urban street lamps, concentrators or PLCs are usually used as RTUs, and the subordinates are a series of collection and control terminal equipment, such as single lamp controllers, leakage detection sensors, anti-theft sensors, etc. It can independently complete the intelligent control of urban street lights when it loses contact with the main control system or the main control system fails. Wireless communication is usually used between the local control system and the host control server, the transmission distance is relatively long, and the communication is easily interfered. As a result, there are often communication delays and errors between the local control system and the master control system server. In order to reduce the communication delay, a communication method with a larger bandwidth is usually used, such as the current mainstream 4G communication. And sometimes in order to take into account the cost, choose 2G or 3G communication with lower cost. In order to reduce communication errors and bit error rates, various error correction algorithms are usually added to the communication protocol between the main control system and the local control to improve communication reliability without affecting the efficiency of information transmission.

3. Data transmission system

The data transmission system in the urban street lamp intelligent control system can be mainly divided into two types: wired transmission and wireless transmission. The wired transmission system realizes data transmission by establishing physical communication lines (such as communication lines established by twisted pair wires, optical fibers, etc.) and connecting the communication lines through various wired transmission equipment (such as various protocol converters, etc.). The wireless transmission system usually uses wireless networks (such as GPRS, zigbee, etc.) and corresponding equipment (such as GPRS communication modules, zigbee repeaters, etc.) to achieve data transmission. In the past, the intelligent control system in urban street lighting usually used PLC (power line carrier) to realize the data transmission between RTU and each control module. In recent years, with the development of Internet of Things and narrowband Internet of Things technologies, technologies such as NB-IOT and LORA have gradually been applied in urban street lamp intelligent control systems.

The Specific Application of Intelligent Control System in Urban Street Lighting

1. Data control

In terms of data management, the urban street lighting intelligent control system is mainly responsible for collecting, analyzing and managing street lighting related assets, troubleshooting data, and system operation data, such as the assets of street lighting equipment (including distribution boxes, light poles, lamps, etc.) Registration and inventory management, management of fault registration and maintenance work, control of street light switch status, time and dimming ratio, etc. The intelligent control system can also count and analyze the relevant data during the operation of street lamps, and find abnormal problems in time (such as abnormal lighting and extinguishing, electricity leakage, etc.). At the same time, the control system can even automatically generate reasonable control strategies or suggestions for users to choose by using big data analysis, AI intelligent module self-learning and calculation.

All collected data and statistical analysis results can be presented using various monitoring terminals (such as PCs, PADs, large-screen displays, etc.), so as to effectively realize control and monitoring. Intelligent control systems usually use a friendly human-machine interface to vividly and intuitively present relevant data and realize control functions. Such as GIS maps, human-computer interaction control interface, various graphical statistical reports, etc., make data management more intuitive and efficient.

2. Energy saving control

With the wide application of LED street lamps, its dimmable functional characteristics have shown significant advantages in energy-saving control of street lamps. A very important application of the urban street lighting intelligent control system lies in the energy-saving control of the system. By formulating a series of automatic control strategies, the system sends the energy-saving control strategy to the on-site terminal equipment for execution, so as to realize the reasonable control of the switching time and brightness ratio of the lights, and finally realize the effective energy-saving control of urban street lighting. By monitoring the on-site terminal equipment, the system can detect and deal with faults such as power theft and leakage in time, thereby effectively avoiding power loss and also saving energy.

3. Communication control

The communication control of urban street lamps is mainly the control of the communication system. The use of intelligent control systems can effectively improve the communication efficiency between the communication modules of urban street lamps. Each communication module in urban road lighting is mainly responsible for the information transmission between the server and the device. Since there are many communication modules, the control focus of the intelligent control system must also be on how to maintain the cooperation between communication modules and maintain the stability of communication links.

The application of urban intelligent system communication control is mainly reflected in the following three aspects:

• First, the communication control needs to ensure the accuracy of the communication. Various error correction algorithms are used to ensure the correctness of the communication between the communication module and the control system.

• Second, communication control needs to ensure the stability and reliability of communication. The heartbeat detection mechanism and long connection mechanism are adopted to realize stable and reliable communication between the communication module and the control system.

• Third, communication control needs to ensure the compatibility and security of communication. Various encryption algorithms and mechanisms are used to ensure the security of communication. Adopt common and standardized communication protocols as much as possible to ensure the compatibility and scalability of communication.
  
  

4. System data inspection management

System data inspection management is aimed at the management of index parameters during system operation, such as system operating status, system equipment online rate, lighting rate, failure rate, etc. These index parameters can be detected by automatic detection or manual collection and dynamic detection. Collect and upload to the system for analysis. After the system receives the corresponding information, it displays it to the user through the monitoring terminal, which is convenient for the user to carry out corresponding processing in time.

In the system data inspection management, the staff need to combine the specific requirements of urban lighting management, reasonably set relevant information, such as collection cycle, alarm threshold, etc., so as to avoid as much as possible. In the system data inspection management, the staff need to combine the specific requirements of urban lighting management to reasonably set relevant information, such as collection cycle, alarm threshold, etc., so as to avoid false and missed reports as much as possible, and also help relevant managers to make correct decisions.

5. System alarm management

During the operation of the system, a series of alarm-related information will be generated. The system needs to set reasonable alarm parameters and algorithms, and analyze the received data to determine whether there are abnormalities and faults in the street lighting facilities, such as confirming the existence of abnormal states (such as If the equipment is offline, the lights are abnormally turned on or off, the switch position is abnormal, the voltage or current is abnormal, etc.), an alarm signal will be sent to provide an effective basis for the management personnel to make decisions.

Application Advantages of Urban Street Lighting Intelligent Control System

1. Improve the informatization and intelligence level of urban street lighting

In the intelligent control system of urban street lighting, not only intelligent control technology is adopted, but also technologies such as Internet of Things, narrowband communication and cloud platform are involved. Through the effective application of these technologies, not only the effective processing of information data can be realized, but also the intelligent control of the urban street lighting system can be realized, thus greatly improving the intelligent level and management efficiency of urban lighting management. For example, in the past, to change the switching time of lights in a city, various personnel and vehicles were needed to reset the on-site timing equipment, which was time-consuming and laborious. And through the intelligent control system, as long as the mouse is moved, it has been realized in an instant.

2. Minimize energy waste

Most cities need to ensure the intensity of street lighting before twelve o'clock in the evening to facilitate people's travel activities; but after twelve o'clock, pedestrians and vehicles will be significantly reduced, and the intensity requirements for urban street lighting are not so high at this time up. If the street lights are kept at a higher brightness all night, it will cause a lot of power consumption. The application of the intelligent control system of urban street lighting can realize the intelligent control and operation of street lights. Relevant management personnel can reduce the brightness of street lights appropriately, or take the method of dividing all-night lights and midnight lights, and turn off midnight lights. Effectively reduce the loss of electric energy.

The intelligent control of urban street lighting is the need to realize the sustainable development of the city. Strengthening the effective use of the intelligent control system of urban street lighting will not only facilitate the management of urban managers, but also greatly reduce the city's power consumption. For this reason, the relevant management personnel must have an in-depth understanding of the main functions and specific applications of the intelligent control system in urban street lighting, so as to improve the intelligent level of urban street lighting control.