Discussion on Wireless Communication Technology in Distribution Network Communication

1 Introduction

The so-called distribution automation is the use of modern electronic technology, computer technology and communication and network technology and power equipment combined with the management of the power sector and distribution network under normal and accidental detection, protection, control, measurement organically integrated , Making the composition of the automation system intact, improving the power quality, improving the reliability of power supply, improving the operation and management level of distribution network, improving the service level of power supply enterprises for users, establishing a closer and more responsible user relationship and ensuring a better power supply economy Sexual, and more effective business management. In distribution automation system, distribution automation network communication is a very important part, but also with the network automation of the nervous system.

2 distribution network automation research present situation

In the early 1970s, Western countries proposed the concept of distribution automation. By the 1990s, after more than 20 years of development, the distribution automation system has formed a relatively mature theory and practical application. Abroad, distribution automation system has formed a number of systems in one distribution management system, such as France, Japan, South Korea and other countries based on their actual needs, to achieve distribution automation, and the effect is better.

In China, distribution automation started relatively late, started in the nineties of last century, lagging 20 years compared with developed countries, so far, the domestic automation of distribution network exploration and research has been ongoing, the distribution network GIS; distribution network DA; distribution SCADA have done research and pilot, and made some experience on it, but did not obtain the success of the practical, mainly due to the communication technology and equipment constraints. In the whole country, many large-scale distribution automation projects have not been popularized at present. In the concrete implementation process, they are mainly pilot projects. With the development of communication network technology, in recent years, the applied research of partial project of distribution network automation has been successful, which lays a good foundation for the planning and construction of distribution network automation.

3 The advantages, disadvantages and analysis of the power distribution network automation communication technology

So far, in the network automation construction, there are two commonly used means of communication: wired, wireless. Wired communication methods include optical fiber communication, distribution carriers and so on. Compared with the wireless communication, the wired communication has the advantages of safety and high reliability, but the construction cost of the leisurely communication is high, the construction is difficult, and the flexibility is poor, which has also become a fatal factor in the popularization and application of wired communication in the distribution network automation Where is the main reason for the delay in the deployment automation automation. For this reason, wireless communication technology becomes the main application of communication technology in distribution automation. At present, the main use of GPRS; 230M radio stations; CDMA public network technology. The following intelligent distribution network for different means of communication are introduced.

4 smart distribution network communication

In both wired and wireless communication methods, wired communication includes: optical fiber communication; audio cable communication; power line carrier communication. Wireless communications include: microwave communications; radio communications; GPRS (CDMA) communications; wireless private network communications. The following is a detailed introduction.

4.1 Optical Communication

In intelligent distribution network communication, optical fiber communication in wired communication is its backbone communication mode. Optical fiber communication has the following advantages: large transmission data capacity and high reliability. There are two more common forms, namely industrial Ethernet switch network, EPON (Ethernet Passive Optical Network) networking.

(1) Industrial Ethernet switch network

In an earlier period, the industrial Ethernet switch networking was mainly used for power optical fiber communication. Optical switches were deployed in the terminal locations to establish fiber optic Ethernet rings based on the EAPS protocol. The industrial Ethernet switch network was in a chain or ring networking mode. The advantages of high bandwidth, ring protection and so on. Ethernet switch network requirements on the number of fiber layout and switches higher, high cost. Intelligent distribution network terminal number is very large, with Changsha City, Hunan Province as an example, just a box-type change can reach more than 5,000 units, if the overhead equipment, station terminals, etc. are also taken into account, this number Can reach tens of thousands. Therefore, the industrial Ethernet switch is not suitable for distribution network communication network construction, mainly because of its high cost.

(2) EPON

EPON's full name is Ethernet Passive Optical Network. In recent years, EPON has developed quite maturely. As a mature optical fiber communication technology, this represents the mainstream of the development of optical fiber communication technology in smart distribution networks. EPON system composed of the following: office optical line terminal (OLT); user side optical network unit (ONU) and their optical distribution network (ODN). Among them, the optical distribution network mainly includes a spectroscopic passive optical branch and a transmission optical fiber.

4.2 audio cable communication

Audio cable communication in wired communications is characterized by lower cost and ease of implementation, but is more susceptible to interference from the outside world. Especially with the 10kV line with the same pole erection, once the line has a short circuit, short circuit current generated in the audio cable will produce a high induced voltage, or even up to 1.5kV, this will give communication terminal equipment operation caused serious damage. Therefore, the audio cable communication has begun to be gradually abandoned by the distribution network communication construction.

4.3 Distribution Carrier Communication (DLC)

Distribution carrier communication in English full name is Distribution Line Carrier, referred to as DLC, distribution carrier communication is to be modulated data into a carrier signal modulation, and then through the coupler, the signal is coupled to the distribution lines or shielding layer, using the present A distribution line as a communication channel of communication, do not need to create a new channel, distribution carrier communication advantages of small investment, wide coverage.

4.4 microwave spread spectrum communication

Microwave spread spectrum communication technology refers to the spread spectrum modulation of the microwave carrier, the original small signal bandwidth broadened into much larger broadband information for transmission of communication. It has low power spectral density and strong anti-interference characteristics, has been widely used in practical applications. However, for the construction of smart distribution network, due to the large investment in communication equipment and engineering in the initial stage of construction and the high cost of operation and maintenance in the future, the signal will be shielded in the tall buildings of the city. Therefore, in the actual construction,