On Suppression Technology Of Fault Alarm For Unclear Power Plants

With the increasing global energy shortage and environmental protection issues becoming more and more prominent,as an important clean energy,nuclear energy is getting more and more attention from the country.China's nuclear power is also actively going out as a national business card to open up overseas markets.With the development and application of digital technology,digital control systems have been widely used in nuclear power plants.Nuclear power plant alarm system and conventional alarm system also undergone major changes,compared with conventional hardware alarm display mode,not only the number of digital alarms are significantly increased,its intuitiveness also decreased.Alarm flooding and keyhole problems will affect the operator's ability to handle alarms effectively.In order to solve the above problems and at the same time to further meet the requirements for alarm reduction[1]in<Nuclear power plants-main control room-alarm functions and presentation>(NB/T 20027-2010),the alarm suppression is necessary for alarm process;in order to relief operator workload,avoid human error and enhance the safety level of nuclear power plant,the alarms which the operator not concerned should be suppressed.The paper first analyzes and explains the alarm suppression solutions which apply for current nuclear power plant,through the time window design method and run length distribution method to suppress jitter alarm;by similarity analysis,Signed Directed Graph knowledge modeling analysis and the relationship topology analysis to identify the associated alarm for alarm suppression.At the same time,in order to achieve the effective management of the alarm,this paper gives alarm grouping and alarm priority management methods.In order to carry out the alarm analysis and the corresponding suppression treatment at the power plant level,this paper proposes an improved alarm suppression and management method based on the operating conditions of nuclear power plants based on the characteristics of the nuclear power plant alarm system and power plant operating conditions,including the definition of power plant conditions and calculation,Based on the analysis method and flow of the topological map of the operating conditions of NPP,the problem of alarm suppression at power plant level can be effectively solved.For safety action,the first cause which triggers a safety action is automatically identified by automatic diagnostics.To assist operators in post-accident analysis to quickly grasp the root cause of triggering safety actions.At the same time,this paper presents alarm dynamic priority design and implementation method based on the alarm management such as alarm grouping and alarm priority,making the alarm priority can dynamically change according to power plant conditions,effectively solve the limitations of the fixed alarm priority,Finally,some suggestions are put forward for the problems that need to be solved and the direction of future development of the alarm suppression in NPPs.