JPH10301618A - Abnormality prediction method and abnormality avoiding method for plant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform highly reliable abnormality prediction and abnormality avoidance by preparing a plant abnormality prediction table for predicting abnormality to be exerted to a plant at the time of the abnormality of a controller and a plant abnormality avoidance table for avoiding it beforehand. SOLUTION: The abnormality generated in the analog input(AI) substrate 1 of the controller 4 is detected by a host monitoring device 5 and abnormality display and warning output are performed. Then, by the plant abnormality prediction table set beforehand, alarming is performed for plant abnormality with the danger of being caused by the abnormality of the AI substrate 1. Further, by the plant abnormality avoidance table set beforehand, the avoidance method of the plant abnormality is deduced. Operation guidance is displayed to the host monitoring device 5 in the case that an operator is present and a command for switching to a manual mode is automatically outputted from the host monitoring device 5 to the controller 4 in the case that the operator is absent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for predicting a plant abnormality caused by an abnormality in a controller and a method for avoiding the abnormality in a plant controlled by the controller.

[0002]

2. Description of the Related Art Conventionally, there is a plant that performs automatic control using a controller. In such a plant, it is necessary to prepare for a response when an abnormality occurs in the controller. This is because if an error occurs in the controller, not only can the plant not be automatically controlled,
This is because it may cause an abnormality in the plant itself and cause serious damage.

[0003] For this reason, conventionally, when an abnormality has occurred in the controller, a method has been adopted in which an alarm is output to a host monitoring device to notify an operator of the abnormality of the controller. In this way, if the operator is stationed at the host monitoring device and it is possible to immediately understand the effect of the controller abnormality on the plant, appropriate actions can be taken promptly. It is valid.

[0004]

However, if no operator is stationed at the higher-level monitoring device, or if it is not possible to immediately understand how the abnormality of the controller affects the plant, There are various problems.

[0005] For example, how the abnormality of the controller affects the plant will be described with reference to a conventional plant monitoring system shown in FIG. In the plant shown in the drawing, the distribution pressure of the pump 1 is normally measured using the pressure gauge 3, and the measurement signal is input to the AI board of the control controller 4. Also, the pump 1
, And the set value is transmitted to the controller 4. The controller 4 calculates the difference between the actual value of the water distribution pressure and the set value and increases the pump rotation speed from the DO board of the controller 4 to the pump 1.
Outputs a decrease command. In this way, constant control of the water distribution pressure of the pump 1 is automatically performed.

In such a state, for example, a case where an abnormality has occurred in the AI board 1 of the controller 4 and the water distribution pressure value is held at the current pressure value is shown in FIG.
Will be described.

That is, when an abnormality occurs in the AI board 1 of the controller 4 (step S1), the upper-level monitoring device 5 displays "AI board 1 abnormality occurred" and simultaneously issues an "alarm".
Is output (step S2). On the other hand, the water distribution pressure value is held at the current value (step S3). Next, the presence or absence of a plant abnormality avoidance operation is determined (step S4). If the avoidance operation is performed, the water distribution pressure value is maintained as it is, that is, stable (step S5). If there is no avoidance operation, the target water distribution pressure set value is compared with the hold value (step S
6). If the set value from the host monitoring device 5 is higher than the hold value in this determination, the DO board outputs a command to increase the rotation speed to the pump 1 (step S7). However, even if the rotation speed of the pump 1 increases and the actual water distribution pressure increases,
Since the controller 4 recognizes the held value as the actual water distribution pressure value, the controller 4 continues to output a command to increase the rotation speed. As a result, the rotation speed of the pump 1 increases to the maximum, the water distribution pressure becomes abnormally high (step S8), and the pipe may be ruptured (step S9). vice versa,
When the set value from the host monitoring device 5 is lower than the hold value, the DO board outputs a command to reduce the number of revolutions to the pump 1 (step S10). However, even if the rotation speed of the pump 1 decreases and the actual water distribution pressure decreases, the controller 4 recognizes the held value as the actual water distribution pressure value. Keep doing.
As a result, the rotation speed of the pump 1 decreases to a minimum, and the water distribution pressure becomes abnormally low (step S11), which may cause a water cutoff (step S12).

As described above, even in the conventional plant monitoring system, the upper-level monitoring device detects an abnormality and outputs an alarm. At that time, when an operator is absent or what kind of abnormality occurs in the plant, If the impact is not immediately understood, appropriate measures may not be taken and the pipe may rupture or become disconnected.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a controller abnormality which can predict what kind of abnormality will occur in a plant due to a controller abnormality and can avoid the abnormality. To provide a method for predicting an abnormality in a plant and a method for avoiding the abnormality.

[0010]

In order to achieve the above object, a method for predicting abnormality of a plant according to claim 1 of the present invention is directed to a plant monitoring system having a controller for controlling the plant and a higher-level monitoring device for monitoring the plant. In the control system, on the condition that the abnormality of the controller is detected, the upper-level monitoring device predicts a plant abnormality that may occur later based on the preset plant abnormality prediction table, and the higher-level monitoring device Is displayed as a warning.

According to a second aspect of the present invention, there is provided a method for avoiding an abnormality in a plant, wherein a plant monitoring control system having a controller for controlling the plant and a higher-level monitoring device for monitoring the plant detects an abnormality in the controller. Based on the plant abnormality prediction table set in advance by the host monitoring device, the plant abnormality that may occur later is predicted, and then, based on the preset plant abnormality avoidance table, The present invention is characterized in that the obtained plant abnormality is avoided beforehand.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of a plant monitoring system according to one embodiment of the present invention. In the figure, reference numeral 1 denotes a water distribution pump, which can adjust a water distribution flow rate by changing a rotation speed. Reference numeral 2 denotes a discharge valve, and reference numeral 3 denotes a pressure gauge, which outputs a value of water distribution pressure as a signal. Reference numeral 4 denotes a controller which compares the value of the water distribution pressure input from the AI (analog input) substrate 1 with the target pressure setting, and increases the rotation speed of the water distribution pump 1 from the DO (digital output) substrate 1. Outputs the decrease command.

Reference numeral 5 denotes a higher-level monitoring device which sets a target value of the water distribution pressure and sends a signal to the controller 4 via a transmission line 6. The host monitoring device 5 monitors an abnormality of the plant and an abnormality of the controller 4, and outputs an alarm to notify an operator when an abnormality occurs. Further, the upper monitoring device 5 includes a plant and controller abnormality display, an alarm output, a plant abnormality prediction and an alarm, and a plant abnormality avoidance (guidance display and avoidance operation).
It has a function to output commands.

FIG. 2 is a flowchart showing the flow of processing of the controller and the transition of the state of the plant when an abnormality occurs in the AI board 1 of the controller 4. Now, an abnormality has occurred in the AI board 1 of the controller 4 (step S
In the case of 1), the host monitoring device 5 detects the abnormality of the AI board 1 and displays an abnormality and outputs an alarm (Step S2) to notify the operator of the occurrence of the abnormality. Further, it is assumed that the water distribution pressure value input to the AI board 1 due to the abnormality of the AI board 1 is held at the current value (step S3). Next, as shown in FIG. 3, a warning about a plant abnormality that may be caused by the abnormality of the AI substrate 1 is issued by a preset plant abnormality prediction table (step S4). Here, for example, "water distribution pressure may be abnormal" is displayed (step S5). Further, as shown in FIG. 4, a method for avoiding a plant abnormality (in this case, a water distribution pressure abnormality) is determined from a "plant abnormality avoidance table" which is also set in advance (step S6).

Next, it is determined whether there is an operator (step S).
7) When an operator is present (step S8), an operation guidance is displayed on the host monitoring device 5 (step S9), and the operator performs an appropriate operation such as switching to a manual mode according to the guidance (step S9). When there is no operator (step S10), a command to automatically switch to the manual mode is output from the host monitoring device 5 to the controller 4. When the operator leaves the seat, the mode is switched to the mode of absence of the operator, and when returning to the seat, the mode is switched to the mode of presence of the operator. As a result, the water distribution pressure value is maintained at the current level (step S11), and a state of abnormal water distribution pressure can be avoided.

As described above, according to the present embodiment, the controller 4 is controlled based on the "plant abnormality prediction table" and "plant abnormality avoidance table" which are set in advance.
And a method of avoiding an abnormality caused by the plant.

[0017]

As described above, according to the present invention,
In a plant monitoring system controlled by a controller, when a controller abnormality occurs, a plant abnormality prediction table that predicts an abnormality affecting the plant and a plant abnormality avoidance table that avoids the table are created in advance, so that a plant due to a controller abnormality can be controlled. Therefore, it is possible to provide a highly reliable and practically excellent plant abnormality prediction and abnormality avoidance method.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a plant monitoring system according to an embodiment of the present invention.

FIG. 2 is a flowchart when an abnormality occurs in an AI board of the controller in FIG. 1;

FIG. 3 is a diagram showing an example of a table for predicting a plant abnormality caused by a controller abnormality used in the present invention.

FIG. 4 is a diagram showing an example of a table for avoiding a plant abnormality caused by a controller abnormality used in the present invention.

FIG. 5 is a configuration diagram of a conventional plant monitoring system.

FIG. 6 is a flowchart showing a process until an abnormality occurs in a plant due to a controller abnormality in the plant monitoring system shown in FIG. 5;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Water distribution pump, 2 ... Discharge valve, 3 ... Pressure gauge, 4 ... Controller, 5 ... Host monitoring device, 6 ... Transmission line.

Claims (2)

[Claims] In a plant monitoring control system having a controller for controlling a plant and a higher-level monitoring device for monitoring the plant, the higher-level monitoring device is set in advance on condition that an abnormality of the controller is detected. A plant abnormality prediction method, comprising: predicting a plant abnormality that may occur later based on the plant abnormality prediction table, and displaying a warning on the upper monitoring device. 2. In a plant monitoring and control system having a controller for controlling a plant and a higher-level monitoring device for monitoring the plant, the higher-level monitoring device is set in advance on condition that an abnormality of the controller is detected. Based on the plant abnormality prediction table, based on the predicted plant abnormality that can occur later, based on a previously set plant abnormality avoidance table, to avoid plant abnormality that can occur later beforehand. To avoid abnormalities in the plant.