Design Of Digital Protection Platform And Research On Algorithm For 110KV Line Protection

The thesis researches mainly the digital protection platform, which includes the design of whole project, the design of hardware and software of logic and excute unit. The algorithm relate to 110KV line protection is also studied.The thesis not only summarizes the history phases and actuality of the digital protection but also foresees its intending development. The paper points out that the function of digital relay protection is developing in the direction of network and intelligence. Meanwhile, the makeup and algorithm of 110KV line protection is introduced.Firstly, as the core hardware of 110KV line protection and transformer protection are similar, different protections can be realized by configuring different software according to demand of network and intelligence. Therefore, a digital protection platform scheme based on Ethernet and CAN bus is put forward. In accord with this scheme, the thesis introduces summarily the thorough research and design of the hardware system of the modularized and united microcomputer protection platform applied in various protections, including communication unit, MMI unit, A/D conversion unit, logic and execute unit. The thesis also analyzes the design and realization of each module and argues the reliability and real time of communication.Secondly, following the idea which IO part can be configured neatly, we introduce particularly the hardware system of logic and execute unit including Ethernet communication interface, CAN bus interface, time-adjust and time-mark circuit, digtal I/O expansion circuit, relay unit and so on. Anti-jamming design of logic and execute unit is emphasized.Thirdly, four pivotal parts of the driver of the logic and execution unit are discussed, including the match of read-write command format in CAN communication, the soft design of synchronization between DSP timer and real time clock, error correct of time-ajust and time-mark, priority management of various interrupt service routine.The thesis introduces the main flow of line protection based on the characteristic of 110KV line protection. Aiming at the defect of the impedance criterion in operation complexity, the impedance criterion is replaced by new power criterion to avoid division and reduce operation time effectively. At the same time,a simple form of phase comparison is introduced.Besides, the thesis aims at the problems encountered during the debug process such as "distributing memory space ", "pipeline conflict","FLASH in system programming"/'realization of parallel boot" and so on, thus promoting the resolve schemes on these questions.In the end, the thesis concludes the main contribution and the work to be continued, and raises some research topics after it.