Communication Reseach Of 35kV Power Line Protection & Monitoring Device Based On IEC 60870-5-103

The relay protection devices are among the most important devices, which ensure the stability of power system. Recently, with the popularization of the technique of Integrated Substation Automation, it becomes a universal requirement for power divisions in every country to research and develop the microcomputer detecting and controlling protection devices, which could integrate the functions of protection, measurement, control and communication.This thesis firstly presents a brief of the software and hardware for developing 35kV line protection device. The protection algorithm adopted in this device is described, with the flowchart and the logic diagram of the protection put forward. Moreover, several major electric remote protocols employed in Substation Automation Communicated systems are described. The universally applied relay communication protocol, IEC 60870-5-103, is specified in this paper, while the functions of the application layer, the transmission regulations of link, the three-layer reference model and the communication picture format are researched specifically, and the realization of 103-protocol on 35kV line protection device is presented. The software is based on the programming of VC++ 6.0, while SQL Server is adopted as the database server.Finally, expert tests are implemented on the device. The result shows that the device could realize the functions of basic protection, remote control, remote signaling and remote measuring. Compared with the traditional microcomputer protection devices, it also bears the merits of higher measurement accuracy, faster and more reliable actions and the ability to carry on distantance communication.