Research On Application Of PRP To The Control Network For Digital I&C Of Nuclear Reactor

Redundancy technology can be an effective solution to improve thecommunication reliability of EPICS (Experimental Physics and Industrial ControlSystem) when applied to nuclear reactor, and the most popular redundancy method isstandby mode with the switching time less than1second.Different from thewidespread use of current redundancy technology,the Parallel Redundancy Protocol(PRP) released in standard IEC62439-3is proposed as a possible solution to providezero switching time in case of a single-point failure. In order to further improve thereliability of EPICS to fulfill the high-reliability requirements of redundancy controlnetwork in nuclear reactor, the parallel redundancy mode elaborated in PRP isinnovatively applied to the nuclear reactor,and a theoretical study of EPICSredundancy technology based on PRP is performed.Firstly, the principle of PRP achieving high reliability and high availability isanalyzed in detail, and a new implementation of PRP has been studied in theApplication Layer.Then, a software implementation of PRP defined as a client/servermodel has been developed based on TCP/IP over Linux by socket programming andmulti-process programming. The main work and achievements are as follows:development of a network driver based on TCP/IP by socket programming, control ofdata sending and receiving by multi-process programming, implementation of dropwindow algorithm to handle the duplicative frames,and so on. Test results show thatthe high reliability requirements of zero self-healing time and zero packet loss can berealized during the simple data transmitting experiments across the various networknodes.Secondly, Channel Access (CA) protocol,as one of EPICS’s core Mechanism, isbriefly introduced,and the feasibility of EPICS achieving high reliability based onPRP technology is analyzed.Then, a software implementation example of CA protocolof EPICS has been developed over Linux based on the PRP which implemented onthe Application layer. The main work and achievements are as follows: study sourcecode of CA protocol, research on the implementation of applying PRP technology toCA protocol, a software redundant communication module of EPICS has beendeveloped based on PRP,control of data sending and receiving by multi-threadprogramming and thread synchronization technology, and so on. Finally, through constructing a parallel-redundancy test platform of EPICS,apeer-to-peer communication network test is performed. Test results show that thehigh-reliability requirements of completely seamless switchover can be realized whena single-point failure occurs in the redundant network. With the proposedimplementation plan,the redundant EPICS based on PRP can be employed to achievehigh-reliability network for nuclear reactor’s I&C system. Overall,the thesis providesa way to implement PRP technology to nuclear reactor’s I&C system.