Research & Implement Of Communication Technique For 35kV Power Line Protection Device

With the rapid development of modern electric power system towards informationlization and intelligentization, communication technology has been the key of the development. The communication based on bus is one of absolutely necessary functions of the rising intelligent power line protection devices. Therefore, researching the related theories and developing corresponding products are very necessary and important to the accelerative development of electric power system.Firstly the current status and general situation of substation automation system and the relevant communication technique are summarized in this dissertation, and then bus modes of communication and their topologies are outlined. Cyclic remote motion CDT and 103 protocols are respectively adopted to realize RS-485 communication of 35kV power line protection device, in which TMS320LF2407A is used as the main micro-processor. Based on the device, the ISA300 protocol of Shenzhen NARI Corporation is successively applied to realize CAN-bus communication. In the process of software design, API and Database technology are combined with the programming and the method of mapping table is employed to calculate CRC check code. Finally, the problems encountered in debugging program and the corresponding solutions are also introduced to improve communication velocity.Preliminary test results demonstrate that the behavior of communication system developed in this dissertation is in agreement with the design request. The reliably of both RS-485 and CAN buses verifies that the design scheme of this dissertation is valid and correct to some extent.