Research And Application Of DCS Communication Network Reliability Assurance Technology In Nuclear Power Plant

At present, China's nuclear power plant instrumentation and control field is from the second generation mode control instrument to the third generation of digital control system transformation, our country vigorously promote nuclear power plant instrument control system localization, the network communication is an important part of instrument and control system, the research has important significance. In order to meet the requirements of nuclear reactor protection system in nuclear power plant, the project takes the high reliability network as the research object, and the key technology of the reliability of the communication network is studied in this paper. Main contents are:The reliability as the research starting point, with typical fieldbus and industrial Ethernet as the research object, detailed analysis the CAN bus, PROFIBUS DP bus, the bus control Net. Analysis reliability and safety of technical means, what are the characteristics of, have what effect.Study on the international and domestic mainstream Industrial Ethernet EPA, analyzes each layer fault probability, summarizes the industrial Ethernet reliability reflected in the three aspects of management and redundancy technology, equipment reliability. Abstract principles of network design, the comparative analysis of the EPA and Devicenet/Controlnet/Ethernet, selected Devicenet/Controlnet/Ethernet,and named for the HRNNP(high reliable network of nuclear plant), and describes the overall network reliability analysis. mainly studied the reliability of Device Net Bus of HRNNP, using stochastic high level Petri nets to the layer of security and non security layer structure modeling and reliability calculation, from mathematics and the change of structure analysis of system reliability, structure calculations show the redundancy can significantly improve system reliability; analysis pointed out Device Net reliability problems, select some mature techniques improve the security layer Device Net protocol reliability, these techniques are time expectation mechanism, application layer CRC, improved heartbeat mechanism, redundancy mechanism by bit inversion data retransmission mechanism. Non code security layer, security layer and reliability technology.In MICON test platform, focusing on testing the security layer,performance test, double bus fault test test given in IEC 61784-3 eight kinds of communication failure: repeat message, message loss, insertmessage, message reordering, damage to the message, message delay and message posing, addressing error. The test results meet the requirements,and passed the acceptance. This paper verified the effectiveness and feasibility of the technology, a solid foundation for the next phase of the study lay, summarize and put forward the next stage work outlook.