Research On Seamless Communication System In Substation

With the fast increasing of economy, the power supply becomes more important. It's emergent to expedite the development of power system. Substation is the key position in the power grid. In substation automation, the microprocessor-based protections, intelligent measurements and auto controls etc, are defined as IEDs. These IEDs have complex functions. At the present time, the manufacturers develop their products independently. And, these products are unconformable. That is a matter for consumer to choose the products. If you have chosen one of the products, you would not apply the others any more. It's a big trouble for consumer to maintain and update the system. To solve these problems, the IEC constitutes the standard of Communication Networks and Systems in Substations (IEC 61850). The seamless communication system in substation is based on the IEC 61850. This standard stresses that the system must be an open and cooperative system. So it can realize the cooperation of different products.In the process of research on the seamless communication system, the method of "from bottom to top" is used in this thesis. That is, in the first place, to study the basic technique which the IEC 61850 used. In substation automation, the IEC 61850 uses the Ethernet as the communication network and the MMS protocol as the application layer protocol of network. How to use the two technologies within substation is studied in this thesis.First, an interface convert card is designed, which can convert CAN field bus and RS-485 bus to Ethernet. This card will build up the hardware platform of the seamless communication system. This card firstly realizes the connection between CAN field bus and Ethernet. It has the advantage of low-cost and fast developing. The original network can be converted smoothly to the Ethernet.Second, MMS protocol is studied, which is one of the application layer protocols of network. And the power system objects are modeled to the communication models with MMS. Finally, a substation automation system is designed, which is based on the MMS protocol. In this design, the substation automation system is partitioned into several parts according to the functions. Each part is independent in some sense and may be maintained individually. In the realization, some advanced technologies are used, such as system service, ADO, intelligent management of communication object etc.The work of this thesis will contribute greatly to the establishment of the substation seamless communication system.