JPS60138606A - Control system - Google Patents

Abstract

PURPOSE:To cope with any fault of a controller of a using system without giving any disturbance to a plant to be controlled, by providing a tracking device and a fault diagnosing device and controlling the output level when the outputs of both devices are switched. CONSTITUTION:If a fault of a controller 1A of a using system is due to a sudden change, the deviation between a control signal Qa of a using system and a control signal Qb of a waiting system and the variation of a process quantity P are immediately produced. Thus a fault diagnosing device 3 works in a short time to detect the fault of the controller 1A. Then the device 3 gives a switch signal S to a control system switch 2 to start a controller 1B of a waiting system. In case the controller 1A has a fault owing to a slow change of its control signal, a deciding circuit 4B applies a decision signal V to a tracking signal output circuit 4C. Then a tracking signal setting circuit 4A applies a tracking signal T to the controller 1B. The signal T is stored previously when the deviation between signals Qa and Qb is small and equal to the normal value of the controller 1A. While the device 3 gives a signal S to the switch 2 to start the controller 1B.

Description

[Detailed Description of the Invention] The present invention provides a system in which a regular system control device that performs integral calculations and a standby system control device that performs the same type of calculation are installed side by side, and the output ends of these two control devices are connected via a switch. Concerning improvements in control systems.

For example, there is a control system configured as shown in FIG. 1 as a control system for a PWR (pressurized watercolor reactor) plant water supply control system. That is, the IA takes in a plurality of process quantities P from the controlled plant shown in the figure, performs an integral (hereinafter abbreviated as PI) operation on them, and generates a regular system control signal Qa that brings the process quantity P closer to the target value. IB is a standby system control device that performs the same type of calculation, and outputs a standby system control signal Qbe in the same way as above. 2
is a control system switching device which selects one of the above-mentioned regular system and standby system control signals Qa and Qb and supplies this selection signal to the controlled plant as a control signal R. 3 is an abnormality diagnostic device that diagnoses an abnormality in the regular system control device IA based on the deviation between the process iP and the regular system control signal Q& and the standby system control signal Qb, and when an abnormality is detected, the control system switch A switching signal S is applied to the controller 2 to switch between the two control devices IA and IB.

In the control system with the above configuration, in the case of a failure in the regular system control device IA where the regular system control signal Qa suddenly changes, the regular system side (the deviation between the iKl signal Qa and the standby system control signal Qb and the process Since fluctuations in jjlP occur immediately, abnormalities in the regular system control device IA can be detected in a short time by the abnormality diagnostic device 3.However, if the regular system control signal Qa changes slowly or becomes fixed, In the case of a failure in the normal system control device 7A, the fluctuation of the no-loss amount P is also slow, and therefore the normal system control device 1A with three abnormality detectors
It takes a long time to detect an abnormality.

In the case of a failure in the regular system control device IA as described above, when the device 3 detects an abnormality in the regular system control device IA and outputs the switching signal S, the standby system control signal Qb is The value is far different from the system control signal Qa. The reason for this is that both the regular system control device IA and the standby system control device IB are PI operation type, so the process IP
This is because the deviation is integrated for the minute deviation of , and as a result, after a long period of time, the value becomes completely different from the original value of the process amount P. ・Standby system control that has changed in this way Since the signal Qb has an excessive value with respect to the fluctuation of the process amount P, when the standby system control signal QbK is switched from the regular system control signal Qa, the process quantity P is opposite to the deviation before switching compared to the target value. direction, causing large disturbances to the controlled plant.

The present invention has been made based on the above circumstances, and its purpose is to prevent any failure of the regular system control device in a control system equipped with a regular system and standby system integral operation type control device. Another object of the present invention is to provide a control system that can be operated by a standby control device without causing disturbance to a controlled plant.

According to the present invention, in a control system in which a regular system control device that performs integral calculations and a standby system control device that performs the same type of calculation are installed in parallel, and the output ends of these two control devices are connected via a switch, tracking Equipped with equipment and abnormality diagnostic equipment,
The configuration is such that the output level is adjusted when the output of both of the control devices is switched, and if the regular control device fails due to a sudden change in its control signal, the abnormality diagnostic device and the switching device are used to control the standby system. In the event that the normal control device has a failure due to a slow change in its control signal, the tracking device uses the pre-memorized normal control output of the normal control device as a tracking signal. The present invention is characterized in that the abnormality diagnostic device and the switching device switch the standby system control device.

The control system according to the present invention will be explained below according to an embodiment shown in FIG. In FIG. 2, the same parts as in FIG. 1 are given the same reference numerals, and their explanations will be omitted. That is, this embodiment has a configuration in which a tiger and king device 4 shown by the dashed line in the figure is added to the conventional device shown in FIG. In the tracking device 4, 4A takes in the regular system control signal Qa and the standby system control signal Qb, respectively, so that the deviation between the regular system control signal Qa and the standby system control signal Qb is small when the regular system control device IA fails. This is a tracking setting circuit that outputs a normal control output value of the regular system control device IA stored in advance in the state as a tracking signal T.

4B, when the normal system control device IA fails by taking in the no-loss amount P, the failure is a failure associated with a rapid change (hereinafter referred to as an abrupt failure), but a failure associated with a slow change (hereinafter referred to as a slow failure). This is a determination circuit that determines whether or not the current condition is the same as the one described above, and outputs a determination signal V only in the case of a slow failure. 4c is a tracking signal output circuit that provides the tracking signal T to the standby control device IB when the determination signal V is applied.

Next, regarding the operation of this embodiment configured as described above, FIGS. 2 and 3 (a) show the case where the device of this embodiment is applied to a PWR plant water supply control system as a controlled plant.
) and (b). ! Figure 3 (,) shows the characteristics of the control output R, SG' (steam soenerator; steam generator) water level and time T when the tiger and king device 4 operate during a slow failure. ) shows the characteristics of the control power R, SG water level, and time T (same as the conventional example) when the tracking device 4 does not operate during a slow failure.

Next, the operation of the above configuration will be described. ◎In other words, when the regular system control device IA is not faulty, the regular system control signal Qa obtained by performing a predetermined integral calculation on the process amount P is sent to the control system switch
is applied to the controlled plant as a control output R.・Next, if a failure occurs due to a rapid change in the regular system control device IA, a deviation between the regular system control signal Qa and the standby system control signal Qb and a fluctuation in the no-rocess IP will occur immediately, as in the conventional device, so the abnormality diagnostic equipment 3 operates for a short time, detects an abnormality in the regular system control device IA, provides a switching signal S to the control system switching device 2, activates the standby system control device IB, and continues predetermined control.

On the other hand, if a failure occurs in the regular system control device IA at time t1 as shown in FIG. becomes dog-like. Then, at time t2, the determination circuit 4B provides the determination signal V to the tracking signal output circuit 4C, and the tracking signal setting circuit 4A determines that the deviation between the regular system control signal Qa and the standby system control signal Qb is the system control signal. Device I
The normal direct tracking signal T of A is sent to the standby system control device 4.
Then, the abnormality diagnostic device 3 gives a switching signal S to the control system switching device 2, which activates the standby system control device IB, and performs the standby system control shown by the broken line in FIG. 3 (&). Signal Qb
is given to the controlled plant as the control output R.

According to the above control operation, PWR as a controlled plant
SG water level control device IA in plant water supply control system
As a result of simulation, it was confirmed that the change (overshoot) after IB switching is 1.5% with respect to the reference value.

On the other hand, when the tracking device 4 of this embodiment is not activated, that is, in the conventional example, as shown in FIG. It has been verified as a result of 7 simulations that there is an overshoot of 18.2%.

As described above, according to this embodiment, the regular system control device I
When B fails, the no-loss amount P at the time of the failure is independent of the integral component accumulated until the failure is detected.
The control output R is given to the controlled plant based on the deviation. Therefore, it is possible to return to a normal control state in a short period of time without causing any major disturbance to the controlled plant), and the Quanno function for the controlled ground is greatly improved.

The present invention is not limited to the above embodiments, and can be implemented with various modifications without departing from the gist of the present invention.

As described above, according to the present invention, a regular system control device that performs integral calculations and a standby system control device that performs the same type of calculation are installed side by side, and the output ends of these two control devices are connected via a switch. The control system is equipped with a tracking device and an abnormality diagnostic device, and is configured to adjust the output level of both of the above control devices when the output is turned off. If the normal system control device fails due to a slow change in its control signal, the above abnormality diagnostic device and the above switching device will switch to the standby system control device. The normal control output of the above-mentioned regular system control device which has been set up is used as a tracking signal and is given to the above-mentioned standby system system i# device and switched to the standby system control device (by the above-mentioned abnormality diagnostic device and the above-mentioned switching device). , in case of any failure of the above-mentioned regular system control device, the standby system iii! A control system capable of dealing with I-controlled devices can be provided.

[Brief explanation of the drawing]

The first part is a block diagram showing a conventional control system, the second part is a block diagram showing one embodiment of the control system according to the present invention, and the third part (a) and (b) are PWkC diagrams showing the same embodiment.
It is a characteristic diagram for explaining the effect when applied to a plant water supply control system. IA... Normal system control device, IB standby system control device, 2... Control system switching device, 3... Abnormality diagnostic device, 4...
- Tracking device k, 4h...Tiger, King (No. 4 foot circuit, 4B...judgment circuit, 4C...tracking signal output circuit.

Claims (1)

[Claims] In the i[ill (Ml system), a tracking device is installed in which a regular system control device that performs integral calculations and a standby system control device that performs the same type of calculations are installed in parallel, and the output terminals of these two control devices are connected via a switch. equipment and an abnormality diagnostic device.
A control system configured to adjust the output level when switching the outputs of both of the control devices.