JPS6054006A - Plant controller - Google Patents

Abstract

PURPOSE:To give stable control characteristics by using a plant simulator due to an identified plant dynamic characteristic model to determine the correction of manipulated variable determination processing procedures with knowledge retrieval each time when plant characteristics are changed. CONSTITUTION:Operation processing procedures stored in the fouth auxiliary procedure storage device 17 are executed for the purpose of identifying dynamic characteristic parameters of a nuclear reactor water supply system, where characteristics are changed, with values which are stored in a numeric date storage part 26 and are detected at past times with respect to the flow rate of supply water, the water level of the nuclear reactor, and the flow rate of main steam. When these procedures are terminated, the numerical simulation which is identified with the state after the characteristic change of a water supply control system and simulates dynamic characteristics is possible by the execution of operation processing procedures stored in the third auxiliary procedure storage device 16. Knowledges which are stored in the sixth auxiliary procedure storage device 19 and can be established by data of primise parts of knowledges are retrieved, and the processing is performed where data coinciding symbolic-logically with parts of conclusions of knowledges are stored in a symbolic knowledge storage device 23. Thus, processing procedures which give a manipulated variable are corrected.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a plant control device that enables adaptive control.

[Background of the Invention] When a plant becomes a multi-input, multi-output system, it becomes difficult to optimally configure its control device using conventional integral control methods such as PID. The determined control method is effective.

While the control parameters of the plant control device remain fixed,
If there are fluctuations in plant characteristics during control, control performance will deteriorate. In order to avoid this situation, an adaptive control method has been proposed that adjusts the parameters of the control device in accordance with plant characteristics that change over time. The objects to which this method can be easily applied are linear systems and simple
This is limited to plants with multiple inputs and multiple outputs, and it is difficult to perform calculations in real time and realize adaptive operation for high-order complex systems.

On the other hand, control method 3) in which a manipulated variable is inferred from a plant state using knowledge obtained empirically from plant control can be applied to a control device that is a multi-input, multi-output system subject to plant controller control. However, even with this method, a parameter adjustment method using calculations based on linear control theory cannot be applied, so adaptive control cannot be realized.

[Purpose of the invention]

An object of the present invention is to provide a plant control device suitable for following temporal changes in plant characteristics and providing stable control characteristics in plant control.

[Summary of the invention]

In order to achieve the above object, the device of the present invention uses a plant simulator based on the identified plant dynamic characteristic model and determines modifications to the manipulated variable determination processing procedure through knowledge search whenever there is a change in plant characteristics. , has the function of stably and favorably continuing plant control after a change in characteristics.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to FIG.

FIG. 1 is a schematic diagram of an example in which the plant control device of the present invention is applied to a BWR reactor feed water control system.

The purpose of the BWR reactor water supply control system is to keep the water level in the reactor 1 constant. Due to the heat generated in the core 2 of the nuclear reactor 1, water inside the reactor turns into boiling steam and exits from the reactor through the pipe P-1. In order to compensate for the loss of reactor water due to this steam, water is introduced into the reactor via pipe P-2 and led to pipe P-3 by reactor feed water pump 3. The reactor feed water pump 3 is driven by the rotational torque of a feed water pump drive turbine 50 connected via the feed water pump drive shaft 4 . Since the reactor water level is adjusted by changing the reactor feed water flow rate, in order to adjust the number of rotations of the reactor feed water pump 30 and the steam flow rate supplied to the feed water pump drive turbine 5 via the pipe P-5, The water supply pump drive turbine control valve 6 is connected to the piping P-
4 and P-5 to adjust its opening degree. The opening degree of the water supply pump drive turbine adjustment valve 6 is determined by the manipulated variable a input to the water supply pump drive turbine adjustment valve opening controller 7 . The plant control device according to the present invention is characterized in that it utilizes various process quantities from the plant, so in this embodiment, the feed water flow rate through the pipe P-2 to the reactor 1 is determined by the feed water flow rate detector 8. The water supply flow rate signal is converted into an electric signal, and the water level inside the reactor 1 is detected by the reactor water level detector 9.
The main steam flow rate from the reactor 1 via the pipe P-1 is converted into an electric signal by the main steam flow rate detector 10, and these are treated as process quantities. In the following, we will first take in the process quantities,
The circuit configuration of the plant control device of the present invention that outputs the manipulated variable will be explained in detail through this implementation, and then the specific processing procedure will be explained using a flowchart.

In FIG. 1, the circuit configuration of the electronic computer 11 mainly consists of five primary parts.

(1) Arithmetic processing unit 12 (2) Storage devices 13 to 2 that stored arithmetic processing procedures (3) Symbolized knowledge storage device 23 that stored symbolized knowledge (4) Input of various process quantities from the plant and Manipulated variable output devices 24 and 25 (5) Storage device 26 for storing numerical data handled in arithmetic processing In FIG. The processing steps are linked together and the processing proceeds while exchanging numerical data related to the processing with the numerical data storage device 26. According to instructions from the processing procedure, the arithmetic processing unit 12 sends the numerical data stored in the numerical data storage device 26 to the manipulated variable output device 25, and the manipulated variable a converted into an electrical signal is outputted to the outside of the computer 11. . Similarly, the process amount input device 2 uses electrical signals.
It was incorporated into 4. Water supply flow rate signal and reactor water level signal C
and the main steam flow rate signal d according to instructions from the processing procedure.
The arithmetic processing unit 12 stores the data in the numerical data storage device 26 via an electrical signal. In addition, the encoded knowledge storage unit 23
The data stored in the storage unit 12 has a list structure suitable for symbolic processing, and can be exchanged by electrical signals from the arithmetic processing unit 12 according to storage units 19 to 22 that store processing procedures for logical operations described later. is only being executed.

The plant control device shown in this embodiment is the arithmetic processing unit 12.
When the operation is started by external power application to the main procedure storage device 13, the main procedure storage device 13 is connected to the main procedure storage device 13 via an electrical signal, and starts executing the processing according to the arithmetic processing procedure stored in the main procedure storage device 13. The means for performing the arithmetic processing stored in the storage devices other than the storage devices described above is configured to perform electrical processing in the arithmetic processing device 12 according to instructions of the processing procedure during execution of the arithmetic processing procedure stored in the main procedure storage device 13. A signal is selected and execution is started. Of the circuit configuration of the electronic computer 110 in this embodiment, the following describes the arithmetic processing procedures stored in the main procedure storage device 13 and other storage devices 14 to 23.

FIG. 2 is a flowchart showing the procedure of arithmetic processing stored in the main procedure storage device 13 in this embodiment.

In the following, the present embodiment will be described using as an example water level restoration control to a steady value after a water level disturbance is applied to a plant.

The steps in the flowchart of FIG. 2 will be explained in order. Step 27 sets numerical parameters used in the arithmetic processing stored in the main procedure storage device 13, other storage devices, and other storage devices 14 to 23. Steps 28 to 33 are repeated as long as there is no change in the plant characteristics, it is determined in step 33 that the parameter value CH is not correct. Step 28 determines the manipulated variable. Step 28 executes the arithmetic processing procedure stored in the first subprocedure storage device. An embodiment of step 28 is shown in FIG. In the embodiment shown in FIG. 4, Step 4 determines the time since the start of the water level return control and writes the numerical data storage device 26 to set the manipulated variable to ul at a certain time t1. Memorize numbers. The explanation will be explained by returning to FIG. Step 29 writes the manipulated variable value stored in the numerical data storage device 26 to the manipulated variable output device 25. The manipulated variable output device 25 converts the written data into an electrical signal a and sends it to the controller 7 of the plant. Since the process amount of the plant changes according to the manipulated variable a, step 30 advances the time by the time ΔT. Step 31 inputs the electrical signals input to the process amount input device by the feed water flow rate, reactor Water level.

The value of the main steam flow rate is converted into numerical data and stored in the numerical data storage device 26. Step 32 executes the arithmetic processing procedure stored in the second subprocedure storage device 14 in order to detect a change in plant characteristics.

One embodiment of step 32 is shown in FIG. In the embodiment shown in FIG. 3, the operation amount a is kept constant and controlled for a time Δ
Processing is performed to compare the process amount after T has elapsed with a simulated process amount obtained by executing a numerical simulator after time ΔT with the same value as the manipulated variable a. In step 33, the same value as the manipulated variable a is read into the numerical data storage device 26. In step 34, process quantities including the feed water flow rate, reactor water level, and main steam flow rate after time ΔT are calculated using a numerical simulator for the reactor water supply system. Step 34 executes the arithmetic processing procedure stored in the third subprocedure storage tree 5. Step 3
Step 5 calculates the difference between the calculation result of the simulated water supply water flow rate and the actual water supply flow rate.In step 36, the magnitude of the difference is determined, and if there is a change in plant characteristics, the numerical parameter CH is set to 1. , if there is no change, C)
The process is terminated by setting I to all 0's.

Returning to FIG. 2, the explanation will be given from step 33, which is the next step after the process of step 33 is completed.

In step 33, the presence or absence of a change in plant characteristics is determined based on the value of the numerical parameter CH. If there is no change in characteristics, the process returns to step 28 as described above and continues the amount control; if a change in characteristics has occurred, control proceeds to step 34. move on.

Step 341d: Identify the dynamic characteristic parameters of the reactor water supply system whose characteristics have changed using the values detected at past times of the feed water flow rate, reactor water level, and main steam flow rate stored in the numerical data storage unit 26. Therefore, the arithmetic processing procedure stored in the fourth subprocedure storage device F is executed. The identification methods in the processing procedure of step 34 include (1) a method in which plant dynamic characteristics are described by a differential equation containing a finite number of parameters according to a physical model, and the parameters are determined by finning, (2) a method using a dose autoregressive model. However, in this example, the above (
An example of a model for case 7' (using method 1) is shown below.

The differential equation of the model is that t is the reactor water level and W is the feed water flow rate.
F-W F s is the feedwater flow rate rated value, and WM- is the main steam flow rate.
Express the amount of operation in m・al * al * tM+tp
*If K2 is a model parameter, the following (1) is obtained.

(2), f3).

dt ・・・・・・(1) c3 t = a1 (W y W M ) W M 'Ill = 82 (WP Wys) + Wpg WM・
...(2) dt Step 35 writes the model parameters obtained as the calculation result in step 34 into the numerical data storage device.

When the processing of the steps up to this point is completed, the state after the characteristic change of the water supply control system is identified, and a numerical simulation that simulates the dynamic characteristics is possible by executing the arithmetic processing procedure stored in the third sub-procedure storage device 16. becomes.

Step 36 refers to data in the encoded knowledge storage device 23 that stores encoded knowledge, and executes procedures based on the knowledge obtained as a conclusion.
) Numerical simulation, (3) Control performance evaluation, (4
) Execute the processes (1) to (4) of modifying the operation amount determination procedure. Step 36 executes the arithmetic processing procedure stored in the fifth subprocedure storage device 18 for this process.

FIG. 6 shows an example of the processing procedure of step 36.

In order to handle knowledge encoded as data through symbolic processing at each step of the processing procedure shown in FIG. 6, this embodiment uses four subprocedure storage devices that store procedures for executing the processing. is added to the circuit configuration within an electronic computer and executed.

Step 43 executes a processing procedure to determine the manipulated variable by determining the time in the control simulation after the plant characteristics have changed. The storage processing procedure executed in step 43 is stored in the sixth subprocedure storage device 19, searches for knowledge that can be established based on the data of the premise part of the knowledge, and searches for data that symbolically matches the conclusion part of the knowledge. Symbolized knowledge storage device 2
Execute the process stored in 3. This procedure is hereinafter referred to as forward inference due to the open circuit. Furthermore, an example of the data stored in the encoded knowledge storage device 23 that is retrieved in step 43 is as follows.

(If (AND (ve$e d $d $t)(v
u $u (time $t1 $t2)) (≧6t
$tl) (($t $t2)) (vu$u$tl) (vuul (timeo, 0 5.0) The method for determining the manipulated variable according to this embodiment is described in the embodiment of step 28 in FIG. An example implementation of step 28 is shown in FIG.

Step 40 executes the same procedure as step 46 by forward reasoning.

Step 44 is based on the manipulated variables of the numerical simulation and the results of knowledge retrieval by forward inference in step 43 (
Search for knowledge based on the data expressed in the list format of VuulO, 0), and calculate the water level, main steam flow rate, etc. Step 44 also searches for next knowledge by forward reasoning.

(If (AND (vxl $, t) (vu$u$4
) (= $tt (+$t time ) (51mn
1ator $x $11) ) (vxflx$tt)
) The time update in step 45 is performed in the knowledge prerequisite part of step 44.

Step 46 searches for knowledge that can be established when this data becomes a conclusion from the data of the part that becomes the conclusion of knowledge, and selects the one that logically matches the data that can be applied to the part that becomes the premise. A procedure is executed to perform arithmetic processing in order to determine whether or not the data of the part is logically established. The symbol processor l@ of this step 46 is stored in the seventh subprocedure storage device 2o.

The procedure of step 46 is backward inference.

In backward reasoning in step 46, knowledge for determining unstable behavior of the plant is searched, and in step 47, a value indicating the type of unstable behavior is assigned to the symbol $C in the conclusion part, and the manipulated variable is determined. Choose whether to continue or exit the procedure correction process.

In step 48, knowledge stored for each symbol assigned to $C is retrieved by forward inference, and in the conclusion part of that one knowledge, correction processing of the operation amount determination procedure according to unstable behavior is executed. In this embodiment, knowledge is stored that includes correction means for setting the time for switching between the two manipulated variables earlier or later.

Step 49 is a process from the time when unstable behavior is detected in the simulation to the time when the manipulated variable switching time is converted.
In order to reset the simulation time, restart the simulation from that time, and return to step 43, the stored encoded knowledge data is erased. The eighth sub-procedure storage device 20 stores procedures for erasing these data. Note that the ninth sub-procedure storage device 21 stores a procedure for storing data in the encoded knowledge storage device 23, and is used when performing forward inference processing.

In step 47, stable control performance is obtained as a result of the simulation, and it is no longer necessary to modify the manipulated variable correction procedure, and it is determined that 5C=O.In step 50, operation is performed from the encoded knowledge data storage device. The numerical parameters included in the quantity determination procedure knowledge are extracted and written in the numerical data storage device 26 as numerical data in step 51, and the process of step 36 in FIG. 2 is completed. Thereafter, step 28 executes the modified manipulated variable determination procedure.
Determine the operating amount a to the ground immediately after the plant characteristics change.

Although the embodiment of step 28 was explained using a procedure for determining the manipulated variable a'tl by determining the time, the difference between the set value of the plant quantity stored in the numerical data storage device 26 and the plant quantity and the A procedure for determining the manipulated variable a according to time changes is also an example. In this case, the plant control device according to the present invention can cope with this by simply changing the representation of the knowledge of the data stored in the encoded knowledge storage device 23.

The effects of this embodiment described above are shown as numerical examples in FIGS. 7 to 10.

FIG. 7 shows that the plant control device according to this embodiment can achieve water level recovery control performance after a 15% water level rise disturbance is applied during fixed value control of the reactor water level.

A-1 is the reactor water level, B-1 is the feed water flow rate, and C-1 is the time change in the manipulated variable. @Figure 7 is an example in which the plant characteristics do not change during control. The discrete value switching control method shown by C-1 has the effect of halving the settling time compared to the change in reactor water level shown by D-1 using the conventional three-element control method.

Figure 8 shows a water level return given by adaptive control in the plant control device according to this embodiment, assuming that the drive capacity of the feed water pump changes and the gain increases immediately after a reactor water level disturbance is applied. Indicates control performance.

Figure 9 shows water level recovery provided by adaptive control in the plant control device according to this embodiment, assuming that the drive capacity of the feed water pump is reduced and the gain is lowered immediately after a reactor water level disturbance is applied. Indicates control performance. In FIGS. 8 and 9, A-2 and A-3 respectively indicate the reactor water level, B-2 and B-3 indicate the water supply flow rate, and C-2 and 0-3 indicate the time changes in the manipulated variables. For the manipulated variable C-2, the time to take the value 0.3 is shortened to prevent the water level change from undershooting.For the manipulated variable C-3, the time to take the value 0.3 is lengthened. , the temporal change in the manipulated variable was corrected from C-1 so that the water level could be better settled.

According to this embodiment, even if the reactor water level disturbance occurs in a stepwise manner and the characteristics of the feed water pump change during that time, good water level return control characteristics can be continuously obtained.

FIG. 10 shows in detail the results of numerically calculating the temporal change in core fuel center temperature. T-1 indicates a time change in the maximum temperature of the fuel center during the water level return control using the manipulated variable C-1 in this embodiment.

T-4 shows the temporal change in the fuel center maximum temperature during the water level return control using the three-element control system.

According to this embodiment, the health of the fuel can be maintained without excessive transient temperature changes, and the water level can be restored in a short time.

〔Effect of the invention〕

The present invention is a general-purpose plant control device that identifies the plant dynamic characteristics even if the plant characteristics change while controlling the transient state of the plant, and provides processing for providing manipulated variables through numerical simulation and symbolized knowledge retrieval. It has a circuit configuration that allows procedures to be corrected in real time, and knowledge that can be applied to a wide range of types and degrees of changes in plant characteristics and control conditions can be memorized and used, so it can adapt to various unexpected changes. It maintains stable control characteristics and has the effect of improving plant operation efficiency.

[Brief explanation of the drawing]

Fig. 1 is a circuit configuration diagram showing an embodiment in which the device according to the present invention is applied to a BWR reactor water supply control system, and Fig. 2 explains the manipulated variable calculation function and processing procedure in the plant control device of the same embodiment. Figures 3, 4, 5, and 6 are flowcharts to explain in more detail the processor shown by the flow port in Figure 2. Figures 7 to 10 are FIG. 7 is a diagram showing response waveforms of various process quantities to reactor water level disturbance in the same example. DESCRIPTION OF SYMBOLS 1...BWR type reactor, 2...Reactor core, 3...Reactor feed water pump, 4...Water pump drive shaft, 5...Water pump drive turbine, 6...Water pump drive turbine Control valve, 7... Feed water pump drive turbine control valve opening controller, 8... Feed water flow rate detector, 9... Reactor water level detector, 10... Main steam flow rate detector, 11... ·Electronic computer. 12... Arithmetic processing device, 13. 22... Arithmetic processing procedure storage device, 2, 3... Symbolization knowledge storage device, 24.
...Process amount input device, 25...Manipulated amount output device,
26 Figure 1 Skull 20 Figure 3 Rod 4-Figure Figure 5 Box 60

Claims (1)

[Claims] 1. A plant, 5. A plurality of detectors for detecting process quantities of this plant, a process quantity input device for an electronic computer that inputs the output signals from these detectors, and - a device for determining the manipulated quantities to the plant. A storage device of an electronic computer that stores means for arithmetic processing, an arithmetic processing device that executes the processing according to the steps of the arithmetic processing stored in the storage device, and an operation amount to the plant from the arithmetic processing results of this arithmetic processing device. In a circuit configuration consisting of a manipulated variable output device of an electronic computer that converts and outputs electrical signals, arithmetic processing is performed to calculate plant dynamic characteristic parameters using the values of various process quantities read into the process variable input device. a first means for calculating the simulated process quantities of the plant based on the plant dynamic parameters calculated by the first means; The values of various process quantities and the 20th
The third step is to perform arithmetic processing to detect changes in plant characteristics by comparing the values of the simulated process quantities calculated by the means.
and a fourth means for performing arithmetic processing to modify said means for configuring a processing procedure based on the encoded knowledge and performing arithmetic processing to determine the amount of operation to be performed on the plant; In order to search for knowledge that can be established using the data of the prerequisite part of the knowledge when using coded knowledge by the means of , and add data that logically matches the part of the knowledge that is the conclusion to the coded knowledge. a fifth means for performing arithmetic processing on the knowledge encoded in the fourth means, and searching for knowledge that can be established when this data becomes a conclusion from the data of the part that becomes the conclusion of the knowledge when using the knowledge encoded in the fourth means; A sixth means performs arithmetic processing to select logically matching data from data applicable to the part that becomes a conclusion and determine whether or not the data of the part that becomes a conclusion is logically established; and a fourth means encodes it. When using the encoded knowledge, a seventh means performs arithmetic processing to add new encoded knowledge, and when using the encoded knowledge sound in the fourth means, erases the encoded knowledge. and a ninth means for performing arithmetic processing in order to combine the above first to eighth means and the arithmetic processing means stored in the storage device. 1
The storage device of the electronic computer that stores the ninth means; the knowledge storage device that stores the encoded knowledge used in the fourth means; and the knowledge storage device that stores the encoded knowledge used in the fourth means; A processing procedure in which a numerical data storage device is provided to store the numerical data provided as a result, and the manipulated variable is determined by logical judgment combined with knowledge in order to continue stable control even after changes in plant characteristics. A plant control device characterized by modifying and realizing adaptive operation.