JPS58129315A - Abnormality detecting device in plant - Google Patents

Abstract

PURPOSE:To detect abnormality of the plant accurately, by subtracting the measured value from a stored model of the plant, and comparing the subtracted value and the value obtained by sampling the subtracted values. CONSTITUTION:The measured value y of the plant is subtracted 3 from the model value x of the plant, which is stored in a computer 1. Then, the value, which is obtained by sampling the subtracted value x-y at every sampling time T, is subtracted 4 from the subtracted value x-y. A comparator 6 outputs a ''1'' when the output of the subtractor 4 is out of a predetermined range, and the abnormality of the plant is displayed 7.

Description

[Detailed Description of the Invention] The present invention is a method of comparing a model representing the behavior of ground variables such as pressure and temperature in a normal state 11 in a thermal power grand, a nuclear power ground, etc. with measured values from an actual run. The present invention relates to a type of plant abnormality detection device for detecting that a real runt is in an abnormal state or is heading toward an abnormal state 111.

Conventionally, if the grand variable value obtained by del is the true value, and the O detection value is 1, and the difference between As shown in Figure 1, if the value of %x, 1 is taken on the vertical axis and the time tl is taken on the horizontal axis, IyO
It is determined which of the Ilk lines deviates from the curve of X using the point x7 as an index.

However, given the two examples of Fig. 1 and Fig. 2, in the conventional judgment method, the index X-F is larger in Fig. 1 than Fig. 2. ga x, y song 01
Since 1 degree is bad, it can be concluded that Figure III is abnormal and 2nd EO is normal. However, conventional abnormality detection devices using X-7 as an index cannot detect abnormal conditions with sufficient fidelity.

The present invention was proposed in view of the above circumstances, and aims to provide a gland abnormality detection device that improves the accuracy and reliability of abnormality detection, and which stores a gland model and uses variable machinery of the same plant. a calculator that calculates and outputs a model value of a quantity, a measuring device installed in the ground that actually measures the variable mechanical quantity, and a first subtraction that receives the actual measured value output of the measuring device and the calculated delta value output. a second subtracter that directly receives the output of the first subtracter; and a second subtracter that receives the output of the first subtracter and transmits it to the second subtracter and holds the transmitted output constant for a predetermined period of time. ringing circuit and the above 11
20 Ratio that receives the output of the subtracter and determines the magnitude of the same output.
The tube is characterized by having a container.

An embodiment of the present invention will be explained with reference to the drawings. Fig. 3 is a diagram showing the circuit configuration thereof, and Fig. 4 (4) (B).
(C) (B) and Figure 5 (4) 俤) (C) (B) are lines showing the output waveforms of each part in Figure 3 when xey is distributed as in Figures 1 and 2, respectively. It is a diagram.

In the above figure, 1 is the calculated value of f run F! 2 is an actual plant that outputs the ground measurement value yt, 3 is a subtractor that inputs the blunt variable xt+ terminal, and also inputs the lcf runt measurement value yt to the terminal and outputs x-yt-.
4 inputs the output of subtractor S to a child terminal, and 4 inputs the output of subtractor 1 to one terminal via sampler 5; is a comparison l
! This is a display that displays the output of #.

Here, the sunglasser 5 samples the input signal at a preset sampling time T and is held for 70 at sampling time T, and the comparator σ samples the input signal at a value within a preset tolerance range. If so, output 0,
If it is outside the allowable range, output l.

In such a device, the subtracter 3 calculates the difference x-yt- between the calculated value I of the model 1 and the measured value y of the actual plant 2.
The difference x-yt is calculated and the sampler 5 samples and holds this difference every sample time interval T.

t+: EmxT (1 is an integer indicating that it is the first sungle). If expressed as the value tx*-ym, the output of sunglass 5 is at time nX
During T≦t((m+1)XT, Xfi-y, t- continues to be output.
During this period, the output is (x-y) - (xn-yn), that is, the change based on the latest sample value is calculated.

Therefore, if this change is within (outside) the preset tolerance range, the comparator 6 will output 0 (1) indicating normality (abnormality).
) is output.

The display r is provided to easily display the above-mentioned normality/abnormality determination result, and the other nine symbols may be used as a trigger signal for the abnormality processing circuit.

Comparing the distributions of Xy7 shown in Figure 1 and Figure 2, the conventional method only sees x-1, that is, uses only the output signals shown in Figures 4 (4) and 5 as information. Therefore, as mentioned above, there is a greater possibility that the example shown in FIG. 1, in which the difference value is large, will be mistakenly recognized as abnormal.

However, if this device is used, the comparator 6 will not output a value of 1 indicating an abnormality in the former case, as shown in Fig. I4 (b) and Fig. A value of 1 indicating an abnormality is output from the comparator 6. This also agrees with the aforementioned human judgment that the former is normal and the latter is abnormal.

As is clear from this example, this device can clearly detect anomalies that are consistent with human judgment.

In short, according to the present invention, there is provided a computer that stores a model of the ground, calculates and outputs the variable mechanical quantity of the plant, and a measuring instrument installed in the ground that actually measures the variable mechanical quantity; a first subtractor that receives the actual measured value output and the delta value output of the calculator; a second subtractor that directly receives the output of the 10th subtracter; and a second subtractor that receives the output of the 1111 subtracter. a sampling circuit that transmits the output to the device and holds the transmitted output constant for a predetermined period of time;
By having a comparator that receives the output of the subtracter and determines the magnitude of the same output, a highly accurate and highly reliable abnormality detection device is obtained, so the present invention is extremely useful industrially. It is.

[Brief explanation of the drawing]

1 and 2 are diagrams showing the distribution of the calculated value X output by the model and the measured value y output by the actual plant, respectively, and FIG. Line diagram, Figure 4 ■ 俤) (Q @ and Figure 5 (4) CB)
(C) and (B) are X e 7 in Figures 1 and 2, respectively.
FIG. 4 is a diagram showing output waveforms of each part in FIG. 3 when distributed as shown in the figure. DESCRIPTION OF SYMBOLS 1...Model, 2...Actual plant, S...Subtractor, 4...Subtractor, 5...Sungler, 6...Comparator, 1...Display device. 1st m! Part 3- Fig. 4 1 Work No. S@

Claims (1)

[Claims] A calculator that memorizes the ground delta and calculates and outputs model values of variable mechanical quantities of the same ground, a measuring device installed at the ground to actually measure the variable mechanical quantities, and an actual edge value output of the measuring device and the above. A first subtracter receives the model value output of the computer, a 20th subtracter receives the output timiI of the JllE10 subtracter, and a 20th subtracter receives the output of the iris 10 subtracter
The present invention is characterized by comprising a numbering circuit that transmits the transmitted output to the 0 subtracter and holds the transmitted output constant for a predetermined period of time, and a comparator that receives the output of the 20th subtracter and determines whether the same output is large or small. Ground abnormality detection device.