The Application Of Industrial Ethernet In Electrical Monitoring & Controlling Systems For Rail Traffic

This thesis analyzes the special characteristics of the monitoring and controlling system of electrical system applied in urban rail traffic and details of functional requirements. Then the necessity and feasibility of applying the industrial Ethernet technology to the system are discussed. After that the thesis takes executive scheme of Shanghai Rail Traffic No.5 as an example to describe the character and requirement of the system applied in urban rail traffic. Finally, the thesis analyzes the digital electrical monitoring and controlling system based on IEC 61850.With the developing of rail traffic and improving of reliability of monitoring and controlling system of electrical system, it is necessary for us to supply more speedy and higher reliable automatic controlling system. Thus the substation can be designed to be unattended operation.Substation controlling unit (RTU, Remote Terminal Unit) can communicate with dispatching centers through the RS485 bus in traditional automatic dispatching scenarios. The scheme requires the engineers to reach the site when there is any fault happened. This costs much time in eliminating the faults. This kind of traditional scheme cannot satisfy the requirements of high reliability and timely. But advanced high speed fiber Ethernet technique supplies effective solution. Fiber networks and switcher connect substations and controlling centers. The scheme can satisfy the requirement of high speed transmission and controlling of data by standard electrical transmission protocol.The control center is equipped with commercial database and multi-function operation stations to implement strong managing function. Substation controlling units collect data from interval levels by site bus protocol to implement the functions of remote communication, remote measurement, remote controlling and remote adjustment. Controlling units are connected with controlling centers to implement RTU function by Ethernet interface. Operation stations of the controlling centers and substation controlling units will construct Ethernet nodes of local net. They can access each other by the TCP/IP protocol. Because of too much incompatible communication protocol, the interoperability between the equipments and the system was largely limited. New communication and system standard IEC 61850 which faced objects and based on Non- Conventional Instrument Transformer and Intelligent Switch was developed. The standard IEC61850 take all-digital and network technology to the substation. It not only concluded and abstracts the function of general substation automation system but also explored a really new technology.