Post on 24-Jun-2020
Science and Technology on Reactor System Design Technology Laboratory
NUCLEAR POWER INSTITUTE OF CHINA
Study for Modeling of Control and Condition Monitoring
Integrated System for Nuclear Power Plant
Chen Zhi, Yu Ren, Zhang Ying, Liao Long-tao
NUCLEAR POWER INSTITUTE OF CHINA -2- 2012/9/23
Outlines
Introduction
The overall scheme of the control and condition
monitoring integrated system
Control and condition monitoring integrated
system modeling
Conclusions
NUCLEAR POWER INSTITUTE OF CHINA -3- 2012/9/23
Introduction (1/2)
The Three Mile Island accident occurred in the 1970s revealed that in order to improve NPP safety and automation level, it is necessary to develop appropriate operation support system (OSS), helping the operator to implement the plant running manipulation better according to the current plant conditions.
Some operation support and condition monitoring systems have been developed: — REACTOR (United States ) — DISKET (Japan ) — ESPED (Korea )
The development of the OSS system provides more guarantee for the NPP.
NUCLEAR POWER INSTITUTE OF CHINA -4- 2012/9/23
Introduction (2/2)
But previous reports indicated that the plant control system and the condition monitoring system to provide support for the operator are designed separately in the most nuclear power plants at present, so
system compatibility,
system resources utilization efficiency
system's extensibility and support for real-time, etc.
is affected, and may have a negative impact on the operation of NPPs .
NPIC and the other university of china are collaboratively developing an new system to perform the control and support functions better. In this presentation, the general scheme of the control and condition monitoring integrated system is introduced.
The modeling study is also carried out by using the IDEF0 (Integration Definition Language 0) and UCM (Use Case Maps) methods for the integrated system.
Try to solve above problem
NUCLEAR POWER INSTITUTE OF CHINA -5- 2012/9/23
The overall scheme of the integrated system(1/10)
1. The function analysis of the integrated system According to the requirements analysis for the nuclear power plant control system and condition monitoring system, the main functions of the integrated are as follows:
a. Data acquisition and management Data acquisition and management are the bases for control and protection, condition monitoring and evaluation and operational decisions.
Data acquisition and management function realizes real-time acquisition of the site parameter information of NPP and sends the information to the relevant equipment to be stored and processed.Then the information can be used by the various subsystems of the integrated system. . b. Control and protection The control and protection function implement the corresponding control and protection action according to the site parameter information, plant operation state and operator command in order to assure the safety and reliability of the NPP.
NUCLEAR POWER INSTITUTE OF CHINA -6- 2012/9/23
The overall scheme of the integrated system(2/10)
c. Critical-safety function monitoring indicates that the current safety state of NPP;
informs the operator quickly once there were some changes which occurred on the important safety state .
Thus helping the operator make the decision quickly and accurately.
According to the safety principle of "defense in depth" for NPP, the six important safety functions should be maintained simultaneously: reactivity control, core cooling, coolant capacity of the primary side, water capacity of the secondary side, the pressure boundary integrity and the integrity of the containment.
In order to monitor the status of the above six safety functions, it is very important to select the correlative parameters properly in the design of the integrated system.
NUCLEAR POWER INSTITUTE OF CHINA -7- 2012/9/23
The overall scheme of the integrated system(3/10)
d. Running conditon assessment and fault diagnosis execute the functions of the analysis and the feature extraction for the acquisition parameters and status parameters
then determine the system's running condition and carry out fault diagnosis.
The system can check the status of the key equipment and engineering safety features (ESF), read the real-time data in the parameter database, evaluate the running condition of NPP and display the analysis results on the human-machine interface. The integrated system also can analyze the parameter changes in the process of plant systems and equipment running and engender the alarm information when the running state deviates from the normal trajectory, thus reminding the operating personnel to pay attention to the related equipment and system status.
NUCLEAR POWER INSTITUTE OF CHINA -8- 2012/9/23
The overall scheme of the integrated system(4/10)
e. Operation guidance The maintenance and system testing before the startup, after the shutdown and in the routine running of the NPP are relatively heavy, but very important work.
By instructing operating personnel to accomplish these tasks with the integrated system,
the burden of operating personnel can be reduced,
the status monitoring for the systems and equipment can be realized automatically.
NUCLEAR POWER INSTITUTE OF CHINA -9- 2012/9/23
The overall scheme of the integrated system(5/10)
Data acquisition
Object to be controlled and monitored in NPP
Parameter trend and sequence analysis
Status knowledge database
Human-machine interface
Operation scheme
database
Operators
Operation knowledge database
Operation situation
monitoring
Abnormal status
detection
Degraded degree
analsyis
System status assessment
and identification
System model
database
Fault diagnosis
Fault orientation
Cause analysis
Consequence evaluation
Evolution forecast
Operation guidance
Normal operation
handle decision
Emergency handle decision
Non-safety handle
detection and restriction
Control and protection
Safety-critical function
monitoring
Fig.1 The function composition scheme of the integrated system
NUCLEAR POWER INSTITUTE OF CHINA -10- 2012/9/23
The overall scheme of the integrated system(6/10)
2. System hardware and software requirements The control and condition monitoring integrated system of NPP will implement the comprehensive control and condition monitoring of the plant, and give the operator manipulate and operation decision-making support.
So its software and hardware systems must meet the following three basic requirements: 1) Reliability requirements
3) System flexibility and maintenance convenience requirements
2) Real-time requirements
NUCLEAR POWER INSTITUTE OF CHINA -11- 2012/9/23
The overall scheme of the integrated system(7/10)
Reliability requirements a. The computer used for condition monitoring and its power supply should be considered to
be redundant. b. The integrated system must work in normal and abnormal operating conditions. c. The malfunction of the non-safety equipment providing information to the integrated
system, shall not affect the ability of processing the required safety information of the integrated system.
Real-time requirements a. acquire the real-time data from the site, process data and analyze data; b. respond to abnormal events in a limited time. c. The manner of inputting data by manual should be simple and quick. d. Rapid completion of the operational guidance, alarms, historical data records are required. e. The reasoning mechanism is as simple and efficient as possible and the size of the
knowledge database should not be too much.
NUCLEAR POWER INSTITUTE OF CHINA -12- 2012/9/23
The overall scheme of the integrated system(8/10)
System flexibility and maintenance convenience requirements a. Users can query, set the parameter and modify the control rules easily.
b. HMI can be achieved
c. When the system is failure or on unusual circumstances, the system itself can take the
appropriate measures or ask for the introduction of the necessary human intervention
NUCLEAR POWER INSTITUTE OF CHINA -13- 2012/9/23
The overall scheme of the integrated system(9/10)
Basic design principles:
System architecture,
human-machine interface,
control and condition monitoring policy, subsystem settings
the system functions realization methods
3. System character and configuration
must be integrated and unified.
NUCLEAR POWER INSTITUTE OF CHINA -14- 2012/9/23
The overall scheme of the integrated system(10/10)
Sensor and actuator device
Control and protection system
Information process and
display system
Operation status assessment and fault diagnosis
system
Operation assistant decision system
Manipulation guidance system
Monitoring and detection
Situation assessment
Response planning
Response implementation
Human-machine interface
Operators
I&Csystem
Object to be controlled and monitored in NPP
Fig.2 The overall framework scheme of the integrated system
The characteristic features of the integrated system will be mainly reflected in the following four aspects : Goals integration The integrated system should be designed and developed collaboratively. Functional integration The design should take into account the cross and overlap in function between the various subsystems. Physical structure integration Uniformity in the structure avoids duplication and inconsistencies of the system modules, thus ensuring compatibility between man and machines and among subsystems. Information integration The integrated system will undertook more comprehensive information processing and analysis methods to improve information display, transmission and switching forms.
NUCLEAR POWER INSTITUTE OF CHINA -15- 2012/9/23
Control and condition monitoring integrated system modeling(1/13)
1. Modeling methods
1) Structured modeling methods IDEF0
The structured modeling method is the method oriented system architecture and based on data flow and function. On the whole, it is a top-down modeling methods.
IDEF0 (Integration Definition Language 0) is a family of IDEF method and its basic idea is to make the user can understand the function and operation of the system through a graphical expression.
IDEF0 model is made up of graphics, text, vocabulary table and mutual cross-reference table, of which the graphics is the main component.
The IDEF0 graphics is always made up of an activity model, an information model and a user interface model, when it is used to express a current operation, functional description or design .
NUCLEAR POWER INSTITUTE OF CHINA -16- 2012/9/23
Control and condition monitoring integrated system modeling(2/13)
Fig.3 The graphical structure diagram of IDEF0 model
Function/ActivityInputOriginal material
Original data
Control
Decision rules
Task parameters
OutputProduct information
Mechanism
DevicePersonnel
Input: resource changed or consumed by the activities.
Control: restrictions in activities operating
Output : the output result of the activity
Mechanism : which execute or actuate the activities
The main modeling steps of application IDEF0 method are as follows: 1) Select the scope, the views or purpose; 2) Establish internal and external relationship diagram (A-O diagram); 3) Draw the top-level diagram (A0 diagram); 4) Establish a series of graphic; 5) Create a text description.
NUCLEAR POWER INSTITUTE OF CHINA -17- 2012/9/23
Control and condition monitoring integrated system modeling(3/13)
UCM (use case maps) is a typical modeling method based on scene.
UCM describes the behavior and composition of the system, as well as the relationships between them in one chart in the view of the entire system. When the UCM is used for system modeling, the level of abstraction is relatively high. details within the system do not fully be hidden. Therefore, this gray box manner makes UCM have considerable flexibility in the expression of the system architecture.
2) The based on scene modeling method UCM
NUCLEAR POWER INSTITUTE OF CHINA -18- 2012/9/23
Control and condition monitoring integrated system modeling(4/13)
The basic elements of the UCM modeling methods are the path, the components and responsibility. Path: the ordered sequence of causal responsibility. Components: refers to software or hardware components, also can be human participants or other systems. Responsibility: the abstraction of actions, activities, operations and tasks performed by the component. The basic idea of the UCM modeling methods is based on the causal relationship of the responsibility executed by components to describe the scene path
Start point
End point Path Basic path
Or-join Or-fork And-join And-fork
Responsibility
Component
Fig.4 The elementary symbols of UCM model
NUCLEAR POWER INSTITUTE OF CHINA -19- 2012/9/23
Control and condition monitoring integrated system modeling(5/13)
3) IDEF0/UCM integrated modeling methods
The IDEF0 method — is suitable to describe the system function composition and flow of information within the system. — lacks the enough expression ability for describing the dynamic model and can not describe the implementation process of a specific function.
UCM method — can clearly describe the dynamic behavior of the system and make the designer understand the system on the overall. — is not suitable to describe the flow of information within the system.
Therefore, integrating the two methods, using the UCM describe the dynamic behavior of the system, and describing the system functions and information flow by IDEF0 method, it is better to model and analyze the system.
NUCLEAR POWER INSTITUTE OF CHINA -20- 2012/9/23
Control and condition monitoring integrated system modeling(6/13)
According to the needs of the integrated system modeling, this study will use IDEF0 and
UCM integrated methods to modeling.
The IDEF0 method is used to analyze overall system, express system activity and data flow
as well as the links between them, and describe the system functional requirements. UCM
method is used to describe the system behavior and composition as well as the relationships
between them.
NUCLEAR POWER INSTITUTE OF CHINA -21- 2012/9/23
Control and condition monitoring integrated system modeling(7/13)
2. Integrated system modeling based on the IDEF0/UCM integrated methods
1) The overall system model
The internal and external relationship diagram A-O established by using the IDEF0 method, as shown in Fig.5.
Integrated control and condition monitoring
systemI2:
Measured parameter
Operator instruction
Actuation singal
HMI informationI1:
O2:
C1
M1
O1:
I3: Required database
Theory and method
Software and hardware resource
Fig.5 The internal and external relationship diagram of the integrated system
NUCLEAR POWER INSTITUTE OF CHINA -22- 2012/9/23
Control and condition monitoring integrated system modeling(8/13)
On the basis of the relationship A-O map, and analyze the dynamic causal relationship between the activities of the various functions of the integrated system, the UCM model of the overall system is shown in Fig.6.
Fig.6 The overall UCM model diagram of the integrated system
Statusassessment
Fault diagnosis program
Hmuan-machine interface
Parameter and condition information
Data acquire equipment
HMI equipment
Data acquire
Control and protection
Control andProtection equipment Actuation
Actuation device
Statusassessment
program
Fault diagnosis
Manipulation guidance
Manipulation guidance program
NUCLEAR POWER INSTITUTE OF CHINA -23- 2012/9/23
Control and condition monitoring integrated system modeling(9/13)
Combined with the internal and external relationship A-O diagram
The components in the overall UCM model are mapped to functional modules of the IDEF0 model
the system top-level IDEF0 model diagram, A0 diagram, can be established,
NUCLEAR POWER INSTITUTE OF CHINA -24- 2012/9/23
Control and condition monitoring integrated system modeling(10/13)
Fig.7 The top-level A0 function diagram of the integrated system
A2
A6
A3
I1 Measured parameter
Data collection module
A1
O1 Nuclear and process parameter
Control and protection module
Alarm signal
O22 Equipment condition informantion
Condition monitoring and assessment module
O3 Conditon, alarm, fault ,and aided computation information
I2 Operator instruction
I3 Required database
C 1 Theory and method
Data management module
O4 Conditon, parameter and alarm information
O21 Control and protection signal
A4
A5
Human-machine interface module
Expert knowledge and instruction
M1 Software and hardware enviroment
O5 HMI information
Operator instruction
Device actuation module
O6 Actuation signal
O2
O21 O22
The system is divided into six sub-modules
Six sub-modules: data acquisition module, control and protection module, condition monitoring and assessment module, data management module, human-machine interface module, device actuation module
NUCLEAR POWER INSTITUTE OF CHINA -25- 2012/9/23
Control and condition monitoring integrated system modeling(11/13)
2) IDEF0 and UCM model of the system module
In order to analyze the functional modules in the A0 diagram more in detail, the further decomposition of the various modules should be needed to get the IDEF0 model sub-graph. The modules can not be breakdown further by the IDEF0 method will be modeled by the UCM method. The condition monitoring and assessment module is taken as an example to describe this process.
A31
A32
A33
C11 C12 C13
M1
A35
A34
I1 Process parameter
I2 Nuclear parameter
I3 Alarm signal
Condition monitoring method
Equipment work condition monitoring
System running condition assessment
Condition assessment method
Alarm analysis method
32O2 Alarm signal
31O Equipment condition information
32O1 System running condition information
Software and hardware enviroment
Alarm process module
Fault diagnosismodule
33O Alarm information
34O Fault information
Auxiliary calculationmodule
35O Auxiliary calculationinformation
Fig.8 The diagram of the condition monitoring and assessment module
The condition monitoring and assessment module can be further divided into five functional modules
NUCLEAR POWER INSTITUTE OF CHINA -26- 2012/9/23
Control and condition monitoring integrated system modeling(12/13)
Fig.9 The diagram of the equipment work condition monitoring module
C11
M1
A311
A313
I1 Process parameter
Condition monitoring method
Condition monitoringbefore startup
311O Condition information
A312
Primary system equipment running
condition monitoring
Control and protection system equipment running condition
monitoring
312O Primary system equipment runningcondition information
313O Control and protection system equipment running condition information
Software and hardware enviroment
The equipment work condition monitoring module in Fig.8 can be decomposed further by using IDEF0 method.
Equipment work condition monitoring module completes the following functions: 1) The status check before reactor startup; 2) The supply voltage check for the important equipment ; 3) Work condition signal check of the control and protection system
NUCLEAR POWER INSTITUTE OF CHINA -27- 2012/9/23
Control and condition monitoring integrated system modeling(13/13)
Fig.9 The UCM diagram of the primary system equipment condition monitoring
The primary system equipment running condition monitoring module A312 , which is shown in Fig.9, as the basic functional unit can not be decomposed further. Their activities can be described by the UCM method.
Running parameterInput interface
Parameteracquisition
Computer program
Running conditionidentification [abnormal]
[normal]
Alarm signaloutput
Condition informationoutput
Output interface
NUCLEAR POWER INSTITUTE OF CHINA -28- 2012/9/23
Conclusions
In this paper, the study of the function composition, information requirements and the overall scheme of the control and condition monitoring integrated system is carried out. A method of combining IDEF0 and UCM is selected to establish system model. The corresponding method and analyzing process in this study can provide the reference for the development of the integrated system of real NPP. Furthermore, the modeling results in this study can be used in the detailed design of the integrated system of NPP. Because the study is still at a preliminary stage, the following work should be done in the next step: 1)Based on the specific objects of NPP, the further refinement for the model should be completed in order to describe the relationship between input and output of the system model in detail; 2) The appropriate software and hardware should be selected to establish the prototype or demonstration system to verify the correctness and rationality of the analysis and design results; 3) The specific realization methods, especially the programming method, need to be studied in order to develop the system smoothly.
NUCLEAR POWER INSTITUTE OF CHINA -29- 2012/9/23
Thank you for your attention!