光纤通信在配电网自动化上的应用之论文

Optical fiber communication in power distribution automation applications on paper（光纤通信在配电网自动化上的应用论文）

With the development of national economy and people's living standards improve, people's growing demand for electricity, while the reliability and power quality of power supply put forward higher requirements. Feeder Automation is the reliability of power supply distribution network systems to improve the most direct and effective means of technology. Countries has increased in recent years on the city network and the transformation of rural power network, power supply bureaus of the major domestic investment in distribution automation is also increasing. Achieved in the distribution network automation process, we found that communication problems is a difficult problem. In this, just from the fiber-optic communication networks in automation applications with little knowledge about and experience.

2 Distribution Automation requirements for communication

SCADA system with the same dispatch, distribution automation system also needs an effective communication network, and he has his own characteristics: the number of terminals very much. System has a large distribution network by opening and closing, power distribution transformers, circuit breakers column to monitor these devices requires a number of FTU and TTU, while the FTU with the power distribution equipment installation, wide geographical distribution, communication nodes scattered.

Distribution automation system size, complexity and automation level of the decision of the communication system should meet the following requirements:

(1) Reliability:

Communications equipment distribution network systems have many exposed outdoors, bad environment, so must be able to withstand heat, cold, sun, rain, snow, hail and lightning and other natural attacks. Meanwhile, try to avoid all kinds of electromagnetic interference, to ensure long-term stable and reliable work, and asked when the line power failure, communication system can still work properly.

(2) economy:

Taking into account the overall economic power distribution system, communication system, investment should not be too large, and strive to make full use of the existing main network communication resources, for the Lord, the overall distribution network planning, avoid duplication of investment.

(3) addressing large:

Communication system not only to consider the present and future data needs, but also consider the upgrade requirements.

(4) two-way communication:

Distribution network automation to achieve the telemetry, remote, remote control, you must request a two-way communication capabilities.

(5) easy operation and maintenance.

According to the above requirements, along with fiber prices down, at present, optical fiber communication systems are widely used in electric power.

3 Optical Fiber Communication

Since the inception of laser and low loss optical fiber, optical fiber communication system with its technical and economic advantages of the rapid rise of unparalleled, and swept the globe. The system is based on optical fiber as the transmission medium to light as the carrier signal to transmit information in communication systems, applications of light wavelength of 1.0 ~ 1.μm Jing, the entire system from the electrical side machine, Optical, cable and repeaters pose. Fiber can be divided into single-mode fiber (SMF), multi-mode fiber (MMF), long-wavelength low drive bulk fiber (LMF), polarization maintaining fiber (PMF) and plastic optical fiber (POF) and so are many; commonly used for single-mode and multi-mode fiber, multimode fiber is more than light transmission mode, and single-mode fiber transmission of a light wave mode only. Single-mode fiber multimode fiber transmission distance than the length, the current general, the optical signal in the multi-mode optical fiber to be available for about 6km, the single-mode fiber transmission within 30km. Therefore, the price of single-mode optical devices than multi-mode optical devices. Practical optical fibers are usually more to strengthen the core, protecting materials, fixed materials combined to form the transmission line cable.

Fiber MODEM to be completed by optical signal and digital signal conversion between. Fiber MODEM generally have more than one data port to transfer synchronous or asynchronous signals. Communication speed up to 2Mbps or higher, with commonly used network communication rate is generally synchronous asynchronous 19200bps N × 64K or less. It is sufficient to meet the needs of distribution network communication, optical fiber MODEM connection diagram is as follows:

In addition, there is a double-loop fiber optic MODEM with self-healing function. This feature greatly enhance the reliability of the communication. Functional diagram shown in Figure 2:

Figure 2 (I) in, A, B, C three is achieved through self-healing optical MODEM loop network, if the point of failure in D, is shown in Figure 2 (II) shows, the optical path in the A station and C stations healing (loopback), the signal is not affected, while the