Development of energy-saving technology for smart street lamps

Street lamps in urban lighting are an important part and link of urban infrastructure. With the acceleration of urbanization, power consumption and electricity bills are increasing day by day. At present, the geographical scale of large and medium-sized cities in my country continues to expand, and the number of urban lighting street lamps is increasing, and the proportion of electricity consumption in the total urban consumption is increasing. Therefore, it is of great significance to analyze the existing mainstream energy-saving technology of street lamps to make the street lamp system achieve energy-saving, comfortable and environmental protection effects, which is of great significance to alleviate the tension of energy supply and protect the environment.

1. The current improvement direction of street lamp energy-saving technology

1.1 Control system improvement

In the past, street lamp control usually used manual methods. The same line agreed to be turned off and on, and the illuminance of the light source could not be controlled, and the degree of intelligence was not high. At present, the lighting monitoring system is composed of a central data control center, a communication system and an intelligent terminal of a street light switch box on site. The system adopts a control method combining time control and light control according to the local sunrise and sunset time and light value. The system can realize voice, sound and light alarms and anti-theft alarms for various faults, improve the operation reliability of urban lighting systems, and have a high degree of intelligence, but the system needs additional communication lines, which is complicated to install and large in scale.

1.2 Circuit improvement

By increasing and improving electrical components, controlling output voltage, current and power, energy saving is realized. Such as SCR voltage regulation. Thyristor is a traditional power electronic device. The principle of using thyristor AC voltage regulation technology is to use thyristor in street lamp power distribution cabinet or box-type transformer to allow AC voltage to pass or turn off intermittently in a cycle to achieve regulation. The purpose of low voltage, but its disadvantage is that the thyristor AC voltage regulation will produce high-order harmonics and line oscillations, reduce the life of the bulb, and if it is a public transformer, it will also cause power pollution. In addition, the circuit improvement technology includes electromagnetic step-down and energy-saving, non-contact voltage stabilization and energy-saving.

1.3 Light source improvement

The improvement of the light source mainly uses high-power LED lights. As a street lamp, LED has high luminous efficiency and low reflection loss of lamps. At present, the luminous efficiency of white LED is about 80lm/W, which can save electricity by 50% to 60% compared with traditional high-pressure sodium lamps. However, at present, the lighting angle of LED lights is small and uneven, the color rendering index is low, and the optical and heat dissipation designs are complicated. The luminous flux under the current technology is not enough, the luminous efficiency is too low, and the quality is difficult to guarantee. In addition, the price of LED street lamps is too high, and it is difficult to promote and apply them in a large area.

1.4 New Energy Technology

Installing power generation equipment on street lamps is the main way for new energy applications. Such as the wind-solar hybrid street lighting system, which consists of wind generators, solar battery packs, controllers, batteries, and light sources. During the day, sunlight and wind resources can be used to generate electricity, and at night, wind generators can be used to generate electricity, which makes up for the singleness of wind or solar power supply, and makes the power supply system more stable and reliable. During operation, the battery discharges to the load to provide power for the load.

The street light switch does not need manual operation, and is controlled by the intelligent time controller automatically sensing the brightness of the sky. New energy technology does not require transmission lines, does not consume electric energy, and has obvious economic benefits. The main problem is that the technology is not mature enough, the investment is large, the investment recovery period is long, and there are few applications at present. Aiming at the characteristics of various energy-saving technologies, this paper proposes a design of a comprehensive energy-saving system.

2. Energy-saving circuit design of smart street lamps

The energy-saving circuit of intelligent street lamp is mainly composed of controller, power conversion and impedance converter. The power conversion unit is controlled by an intelligent controller, so that the primary coil of the variable reactance converter realizes impedance conversion, so as to achieve the purpose of street lamp load regulation and energy saving. The power conversion unit is composed of power electronic power devices, trigger controller, signal detection and processor, etc. By adjusting the control angle of the thyristor to control the current of the secondary coil of the variable reactance converter, the terminal voltage of the street lamp is changed to change the illumination brightness of the street lamp. The primary coil of the variable reactance converter is connected in series with the street lamp load to form a primary impedance series circuit, and its secondary coil and power conversion unit form a secondary impedance conversion circuit. By changing the secondary impedance, the ratio of the primary impedance to the load impedance is changed. Relationship, to achieve load power regulation, thereby changing the street lamp terminal voltage, realizing soft start of street lamps and voltage regulation and energy saving.

3. Intelligent control system design

3.1 System Network

The intelligent control system is divided into two parts: the control center and the unit intelligent control node. The control center reads information from the nodes and sends control commands to the nodes; the nodes transmit environmental information data to the control center, such as light intensity, street lamp information, and node numbers. etc. At the same time, it receives commands from the center to control street lights, light intensity, etc. The entire network communication adopts ZigBee wireless self-organizing wireless network technology. ZigBee technology has a powerful device networking function and supports three main types of self-organizing wireless networks, namely star structure, mesh structure (Mesh) and cluster structure. It is a mesh structure with the advantages of self-configuration, self-healing, and interference reduction, and has strong network robustness and system reliability. Therefore, at least one router (black node in Figure 2) is needed for the entire network communication to complete the network establishment. Greatly simplifies system configuration and complexity.

3.2 Intelligent node system

The hardware of the intelligent control node system is mainly composed of photoelectric sensors, signal conditioning, microprocessors, A/D and D/A converters, etc. The optical signal is converted into an electrical signal through the photoelectric sensor, and is input to the A/D converter through the transmitter. Combined with the command of the external control center, the system is turned on and off. The system block diagram is shown in Figure 3.

epilogue

The energy-saving control system of street lamps based on intelligent control is an efficient and reliable green product. It changes the voltage or current of the secondary coil of the reactor through the intelligent controller and the power electronic power conversion unit, thereby changing the primary reactance value of the reactor, and then changing the input voltage of the street lamp. System installation and maintenance. The street lamp not only effectively realizes power saving, but also realizes the collection of environmental information and realizes the intelligence of the system.

The above is the research on energy-saving technology of smart street lamps introduced by Shenzhen Zuchuang Microelectronics Co., Ltd. for you. If you have design requirements for smart energy-saving street lamps, you can trust us. We represent a variety of single-chip microcomputers, voice chips, dual-mode Bluetooth ICs, and wifi chips. Brands include Songhan MCU, Yingguang MCU, Jerry Bluetooth, Ankai Bluetooth, Allwinner, and Realtek. Our technical services include: PCB design, microcontroller development, Bluetooth solutions, software and hardware custom development, APP development, small program development, WeChat official account development, etc. It can also undertake the design of intelligent electronic products, the development of living appliances, the research and development of beauty equipment, the application of Internet of things platform, the smart home control system, the development of TWS earphones, Bluetooth earphone speakers, the development of children's educational toys, the design of electronic education products, etc.