Plant diagnostic apparatus

Abstract: According to a plant diagnostic apparatus of the present invention, a simulation fault value of the case that an estimated fault occurs is displayed on the screen and therefore diagnostic probability of true-or-false of displayed cause of the fault can be improved. Moreover, since an estimated fault, a simulation value of the case that an estimated fault progresses and a normal period simulation value of the case that no fault occurs are displayed on the same screen, a simulation value of the estimated fault and normal value can be compared for judgement and thereby diagnostic probability of true-or-false decision of the estimated fault can be improved. In addition, since an estimated fault, a simulation value due to the estimated fault and a simulation value of the case that a measure is taken for the estimated fault are displayed on the same screen, probability of true-or-false decision of the estimated fault can be improved by comparing these values.

Description: BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a plant diagnostic apparatus and particularly to a diagnostic apparatus which estimates a failure occurring in the plant and displays simulation value for progress of such failure for convenience of taking measures. Description of the Prior Art Fig. 1 is a block diagram showing a diagnostic apparatus of the prior art. In this figure, an electronic computer 1 comprises an input processing part 3 for inputting process quantity from a plant 2, a fault detecting part 4 for detecting a fault in the input data, a cause estimating part 5 for estimating a cause of the fault from fault phenomenon detected by the fault detecting part 4, a plant transition value data storing and processing part 6 for storing plant data, a plant transition value data file 7, a fault data retrieving part 8, a cause estimating image generating part 9 and a display processing part 11 for displaying data to a display unit 10. Fig. 2 is a flowchart indicating processes for displaying cause estimation and estimated cause in the plant diagnostic apparatus in the prior art. In a plant diagnostic apparatus in the prior art, an input data from the plant 2 is subjected to an input process (step ST1) in the input processing part 3 and sent to the plant transition value data storing and processing part 6 for carrying out a plant transition value data storing process (step ST2) in order to store the transition data to a plant transition data file 7. The input data having completed the input process (step ST1) is then sent to the fault detecting part 4 to monitor change of input data. If the input data deviates from the normal condition, a fault detection process (step ST3) is carried out to detect occurrence of a fault condition. If the fault condition is detected, the cause estimation process (step ST5) is carried out in the cause estimating part 5. When the fault condition is not detected, monitoring is continued. The cause estimating part 5 estimates a cause of fault event detected. The cause data estimated here, together with the fault data having passed a fault period data retrieving process (step ST6) under the fault condition in the fault data retrieving part 8, are sent to the cause estimating image generating part 9 and subjected to a cause estimation image generating process (step ST7). An image generated is displayed (step ST8) on the display unit 10 through the display processing unit 11. A similar diagnostic apparatus is described in the assay "A Knowledge Base System for Plant Diagnosis" of H. Motoda et al. published in "PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON FIFTH GENERATION COMPUTER SYSTEMS" 1984, 6 to 9 November 1984, Tokyo, Japan which defines the closest prior art from which the invention proceeds. According to the above prior art, in case of breaking out the abnormal diagnostic result of the plant model, since the model associated with the fault is not constructed from the model with the normal condition, the fault simulation cannot be performed. As a result, the propriety for the estimated abnormal diagnostic result of the plant model cannot be evaluated. Further, since the simulation to the model after the measure is taken is not performed, the propriety of the measure taken cannot be evaluated as well. Finally, since neither the normal simulation nor the fault simulation are performed thereafter by not displaying the simulation result simultaneously, it cannot be easily to evaluate and recognize the transition of condition. US-A-4 755 925 discloses a plant diagnostic system wherein plant data are described by using an Auto Regressive Model in accordance to which a plant diagnosis is performed by using a time series data. In case of occuring the abnormal diagnostic result of a plant model, the model associated with the fault is not constructed from the model with the normal condition, and then the fault simulation is not performed. Therefore, the propriety for the estimated abnormal diagnostic result of the plant model cannot be evaluated. So, the plant diagnostic apparatus of the prior art have the following problems when the estimated cause is displayed. (a) It has been impossible to know whether or not the plant data has truly been changed to the detected condition by the estimated cause. (b) It is impossible to know the plant condition under the normal operation. (c) It is impossible to know how the plant condition changes when the countermeasure is taken. SUMMARY OF THE INVENTION The present invention has been proposed to overcome these problems and it is therefore an object of the present invention to provide a diagnostic apparatus which comprises the plant characteristic model for normal operation and confirms estimation result of cause by simulating fault model corresponding to estimated cause of fault condition. Moreover, it is also another object of the present invention to provide a diagnostic apparatus which comprises a plant characteristic model under the normal operation and confirms estimated cause by simulating fault model corresponding to estimated cause of fault operation and normal model under the normal operation. It is still another object of the present invention to provide a diagnostic apparatus which comprises a plant characteristic model under the normal operation and confirm estimated cause of fault operation and plant operation after the measure is taken by simulating fault model corresponding to estimated cause of fault operation and the model after the measure is taken. In order to achieve these objects, in accordance with the present invention, there is provided a plant diagnostic apparatus for determining a cause of a fault in a power plant comprising input processing means for inputting data from the plant, a plant transition data file for storing transition values of the plant characteristics based on data from the input processing means, fault detecting means for detecting a fault in the plant based on the data from said input processing means, cause estimating means for estimating a cause of the fault from a fault event detected by the fault detecting means, cause estimating image generating means for generating an image to be displayed by the data from the cause estimating means, display processing means for displaying and controlling the images generated by the cause estimating image generating means, and a display unit for displaying the images by controlling of the display processing means, characterized by a plant characteristic model for storing plant characteristics, simulation control means for generating a simulation model, for the range associated with the fault estimated by the cause estimating means, being extracted from the plant characteristic model, and for calculating the simulation based on data from the plant transition data file and the simulation model generated, and simulation image generating means for generating an image of the simulation value calculated by the simulation control means, said display processing means also displaying and controlling the image generated by the simulation image generating means. Further advantageous embodiments are defined in the subclaims. According to the present invention, the diagnostic apparatus comprises a plant characteristic model for normal operation and confirms an estimated cause of fault operation and plant operation after the measure is taken by simulating a fault model corresponding to the estimated cause of fault operation. Further, during the fault period, the simulation to the model after the measure is taken is performed, and, in regard thereto, the propriety of the measure taken can be confirmed. So, the propriety for the estimated abnormal diagnostic result of the plant model can be evaluated. Moreover, since according to the present invention both the normal simulation and the fault simulation are performed thereafter by displaying the simulation result simultaneously, it can be easily to evaluate and recognize the transition of condition. These and other objects of the present invention will become apparent from the following description taken in conjunction with the preferred embodiments thereof with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a block diagram showing configuration of a plant diagnostic apparatus in the prior art; Fig. 2 is a flowchart indicating operation of the apparatus shown in Fig. 1; Fig. 3 is a block diagram indicating configuration of a plant diagnostic apparatus according to a first embodiment of the present invention; Fig. 4 is a flowchart indicating operation of the apparatus shown in Fig. 3; Fig. 5 is a block diagram indicating configuration of a plant diagnostic apparatus according to a second embodiment of the present invention; Fig. 6 is a flowchart indicating operation of the apparatus shown in Fig. 5; Fig. 7 is a block diagram indicating configuration of a plant diagnostic apparatus according to a third embodiment of the present invention; and Fig. 8 is a flowchart indicating operation of the apparatus shown in Fig. 7. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Each claim of the present invention will be explained in further detail depending on the embodiments shown in Fig. 3 to Fig. 8. In Fig. 3, an electronic computer 1 comprises an input processing part 3 for inputting process quantity from a plant 2, a fault detecting part 4 for detecting a fault in the input data, a cause estimating part 5 for estimating a cause of fault from fault phenomenon detected by the fault detecting part 4, a plant transition value data storing and processing part 6 for storing plant data, a plant transition value data file 7, a fault data retrieving part 8, a cause estimating image generating part 9 and a display processing part 11 for displaying data on a display unit 10. In addition to such conventional configuration, an apparatus in the first claim of the present invention comprises a plant characteristic model 20 for storing various characteristics of plant, a fault period simulation control part 21 for calculating a simulation value when the estimated fault occurs and a simulation image generating part 22 for generating display image of such simulation value, and performs the operations indicated by the flowchart shown in Fig. 4. In Fig. 4, the input data from the plant 2 is subjected to an input process (step ST1) in the input processing part 3, the data is then processed by a plant transition value data storing process (step ST2) in the plant transition value data storing and processing part 6, and is then stored in the plant transition value storing file 7. Next, the fault detecting part 4 monitors changes in the input data and executes a fault detecting process (step ST3) for detecting a fault if operation deviates from the normal condition. When a fault is detected, a cause estimating process (step ST5) is carried out in the cause estimating part 5 and the cause may be estimated from the fault event detected. The estimated cause is sent to the estimated cause image generating part 9 together with fault associated data retrieved by a fault period data retriving process (step ST6) in the fault period data retrieving part 8. Such data are processed and edited by a cause estimating image generating process (step ST7) and are then displayed on the display unit by a display process (step ST8). Next, the fault simulation model generating process (step ST21) is carried out in the fault period simulation control part 21 in such a case that the simulation is required on the basis of the operator's judgement or predetermined judging criteria. A model for the range associated with the fault is extracted and reconstructed from the reference plant characteristic model 20. Moreover, a fault simulation model including the change of plant characteristic from the normal condition to fault condition is generated and the initial data required for simulation model generated by the initial data generating process (step ST12) for simulation is also generated from the plant transition value data file 7. Thereafter, the simulation result of a fault simulation calculation (step ST22) is sent to the plant data simulation image generating part 22. This data is processed and edited by a simulation result image generating process (step ST23) and is then displayed on the display unit by the display process (step ST8). In the above embodiment, a simulation model has been generated for estimated cause but it is also possible to generate a simulation model for a cause arbitrarily designated. Moreover, in the above embodiment, a result of fault simulation is displayed in such a format as convenience to decision making, but a process for estimating another cause may be performed by using the simulation result. According to the claim 2 of the present invention, an electronic computer 1 comprises, as shown in Fig. 5, a plant characteristic model 20, a fault period simulation control part 21, a simulation image generating part 22 and a normal simulation control part 23, in addition to the configuration of the prior art and operates as indicated in the flowchart of Fig. 6. In Fig. 6, an input data from the plant 2 is subjected to the input process (step ST1) in the input processing part 3, and to the plant transition value data storing process (step ST2) in the plant transition data storing and processing part 6, and is then stored in the plant transition value storing file 7. In addition, the fault detecting part 4 monitors changes in input data and carries out the fault detecting process (step ST3) for detecting a fault when operation deviates from normal condition. When a fault is detected, the cause estimating part 5 starts the cause estimating process (step ST5) to estimate a cause of fault from the detected fault event. The estimated cause is sent to the cause estimating image generating part 9 together with data associated with fault retrieved by the fault period data retrieving process (step ST6) in the fault period data retrieving part 8, it is then processed and edited by the cause estimating image generating process (step ST7), and is finally displayed on the display unit by the display process (step ST8). In addition, if the simulation is performed by operator's decision or by predetermined decision criteria, the normal simulation control part 23 carries out a normal simulation model generating process (step ST31) and generates a normal period simulation model for the range associated with a fault from the standard plant characteristic model 20. The fault period simulation control part 21 generates a fault simulation model including changes in the plant characteristics from the normal condition to the fault condition, in addition to the normal simulation model initial data is generated from the plant transition value data file 7 for the simulation model generated by the initial data generating process (step ST12) for simulation, a normal simulation calculation (step ST32) and fault simulation calculation (step ST22) are performed, the plant data obtained by simulation result is sent to the simulation image generating part 22 and this plant data is processed and edited by a simulation result image generating process (step ST23) and is finally displayed on the display unit by the display process (step ST8). In the claim 3 of the present invention, an electronic computer 1 comprises, in addition to the configuration in the prior art, a plant characteristic model 20, a simulation image generating part 22 and a fault/measure simulation control part 24 as shown in Fig. 7. Thereby the computer 1 is capable of displaying the simulation result from the estimated fault and the simulation result in such a case that a measure is taken for such estimated fault on the display unit through the operations indicated in the flowchart of Fig. 8. In Fig. 8, the input data from plant 2 is subjected to the input process (step ST1) in the input process part 3, then to the plant transition value data storing process (step ST2) in the plant transition value data storing and processing part 6, and is stored in the plant transition value storing file 7. Next, the fault detecting part 4 monitors changes in the input data and executes the fault detecting process (step ST3) for detecting a fault when operations deviates from the normal condition. When a fault is detected, the cause and measure estimating part 5 starts a cause and measure estimating process (step ST5). The cause of fault is estimated and a measure to be taken is set according to the fault detected. The estimated cause and measure are sent to the cause estimating image generating part 9 together with the data associated with the fault detected by the fault period data retrieving process (step ST6), processed and edited by the cause and measure estimating image generating process (step ST7) and finally displayed on the display unit by the display process (step ST8). Moreover, when simulation is required based on operator's judgement or predetermined judging criteria, a model for the range associated with fault is extracted from the reference plant characteristic model 20 by the fault and measure simulation model generating process (step ST21) in the fault/measure simulation control part 24. A fault/measure simulation model, which also covers sudden changes in plant characteristics from normal condition to fault condition by taking a measure, is generated, the initial data necessary for the simulation model generated by the initial data generating process (step ST12) for simulation is generated from the plant transition value data file 7, the fault/measure simulation calculation process (step ST22) is carried out and the plant data operation by simulation is processed and edited by the simulation result image generating process (step ST23) and is displayed on the display unit by the display process (step ST8). As described, according to the present invention, (a) an estimated fault and simulation result by estimated fault are displayed, or (b) an estimated fault, simulation result by estimated fault and normal period simulation result without fault are displayed, and moreover (c) an estimated fault, simulation result by estimated fault and simulation result when a measure is taken are displayed, and thereby a true and false decision probability of the estimated fault can be improved. The present invention is not limited to the embodiments described above and covers, for example, other changes and modifications such as executing a process for estimating other causes of fault by comparison with the simulation result of arbitrarily designated fault or with simulation result after taking a desired measure and utilizing the simulation result obtained. As described above, the present invention provides the following effects. That is, according to claim 1, the simulation result in a case where an estimated cause occurs can automatically be displayed. According to claim 2, the simulation result in a case where an estimated cause occurs and the simulation result of normal operation without fault can automatically be calculated, and moreover according to claim 3, the simulation result in a case where an estimated cause occurs and the simulation result in a case where a measure is taken for the fault are automatically calculated and displayed on the display unit. Thereby, the time for estimating a cause of fault can be curtailed, reliability of cause estimation can be improved. In the case of claim 3, moreover, reliability for safe operation of plant by taking a measure can also be improved.

Claims: A plant diagnostic apparatus for determining a cause of a fault in a power plant, comprising: input processing means (3) for inputting data from the plant; a plant transition data file (7) for storing transition values of the plant characteristics based on data from the input processing means (3); fault detecting means (4) for detecting a fault in the plant based on the data from said input processing means (3); cause estimating means (5) for estimating a cause of the fault from a fault event detected by the fault detecting means (4); cause estimating image generating means (9) for generating an image to be displayed by the data from the cause estimating means (5); display processing means (11) for displaying and controlling the images generated by the cause estimating image generating means (9); and a display unit (10) for displaying the images by controlling of the display processing means (11), characterized by a plant characteristic model (20) for storing plant characteristics; simulation control means (21; 23; 24) for generating a simulation model, for the range associated with the fault estimated by the cause estimating means (5), being extracted from the plant characteristic model (20), and for calculating the simulation based on data from the plant transition data file (7) and the simulation model generated; and simulation image generating means (22) for generating an image of the simulation value calculated by the simulation control means (21; 23; 24); said display processing means (11) also displaying and controlling the image generated by the simulation image generating means (22). A plant diagnostic apparatus according to claim 1, wherein said simulation control means comprises a fault period simulation control means (21) for generating a fault simulation model including the change of plant characteristic from the normal condition to fault condition, and for calculating the fault simulation value based on the fault simulation model. A plant diagnostic apparatus according to claim 2, wherein said simulation control means comprises a normal period simulation control means (23) for calculating normal period simulation value based on the simulation model being generated. A plant diagnostic apparatus according to claim 1, wherein a cause and measure estimating means (5) estimates a counter measure to be taken based on a fault event estimated, said simulation control means comprises a fault/measure simulation control means (24) which generates a fault/measure simulation model covering changes from normal condition to fault condition and changes caused by the counter measure to be taken estimated and calculating a simulation value of a case where the estimated counter measure is taken for the estimated fault.

Inventors: EBIZUKA KIYOSHI, EBIZUKA, KIYOSHI, EBIZUKA, KIYOSHI MITSUBISHI DENKI K.K. POWER AND
Applicants: MITSUBISHI ELECTRIC CORP, MITSUBISHI DENKI KABUSHIKI KAISHA
Application year: 1989
Main classification: G06F17
IPC codes: G06F19, G06F17, G08B31, G05B17