JPH02230302A - Plant automatization system - Google Patents

Abstract

PURPOSE:To improve reliability and to reduce cost by permitting respective controllers to refer the automatization sequence of a plant which is stored in a shared memory, and to spontaneously judge objects to be allottably controlled and a control start timing to dispersedly plant-automatization. CONSTITUTION:Measuring instruments 11 as sensors, actuators 12 and the controllers 14 of respective systems are arranged in respective parts of the plant. An optical multiplex transmission device 13 is connected between the measurement instruments 11, actuators 12 and the controllers 14, and the shared memory device 15 is connected to respective controllers 14. The controllers 14 access to the shared memory device 15, read the position of a marker 22 showing a present state corresponding to the control sequence. When the subsequent control of the marker is that allocated to itself, the control is executed, and the position of the marker is advanced by one when control terminates. Thus, the plant automatization system of a distributed multiplex type with high reliability can be obtained.

Description

Detailed Description of the Invention [Object of the Invention] (Industrial Application Field) The present invention relates to a plant automation system that automatically starts and stops a large-scale plant such as a nuclear power plant.

(Conventional technology) Conventionally, plant automation systems for nuclear power plants, etc.
As shown in the figure, there are measuring instruments 1 placed in various parts of the plant, seven actuators 2 for driving pumps and valves installed in the plant, and a predetermined control system for connecting the measuring instruments 1 and actuators 2k. Its component is a control device 3 that controls an actuator 2 based on a signal from a measuring instrument 1. A plurality of such control 1B devices 3 are provided exclusively for each control system of a nuclear power plant (typical examples of which are a water supply control system, a recirculation control system, etc. in a BWR power plant). Generally, these control devices 3 are connected to a process computer 4 of the plant.

The process computer 4 also includes the control device 3.
In addition to inputting signals from a measuring instrument 1 connected to the measuring instrument 1, signals from a measuring instrument provided separately from this measuring instrument 1 are also inputted.

Now, in order to automatically start and stop a plant, it is necessary to sequentially control each system of the plant according to a predetermined sequence. A series of controls for starting and stopping a plant are divided into controls for each system, and are performed by sequentially performing these controls according to a sequence. In the conventional plant automation system, the control device 4 is designed to control each system.

In order to automatically start and stop a plant, each system is controlled according to a predetermined sequence, but in conventional automation systems, this sequence is stored in the process computer 4. There is. In addition, in a series of control sequences, when transitioning from control of one system to control of the next system, conditions to enable the transition (previous conditions) are established. In the conventional automation system, this precondition is stored in the process computer 4 together with the control sequence in the control system, and the process computer 4 preconditions the precondition based on the signals from the measuring instruments 1 and 1' input to itself. Determine whether the conditions are satisfied. If the condition is satisfied, an operation is performed in which a control start signal is issued to the control device in charge of the next system. The control device in charge of the next system receives this control start signal and starts control.

<<Problems to be Solved by the Invention>> However, the conventional plant automation system configured as described above has the following problems.

(1) Management of a series of control sequences in automation such as starting and stopping a plant is not managed by a process computer, and if a malfunction occurs in the process computer, the entire automation control sequence by the process computer becomes inoperable.

(2) In order to avoid the above situation, it is possible to improve the reliability of the process computer by multiplexing the process computers, but this leads to an increase in the size and cost of the process computer.

The present invention was made in order to solve the above problems, and an object of the present invention is to provide a highly reliable and economical plant automation system.

[Structure of the Invention] <Means for Solving Problem Va>> The present invention provides a multiplex transmission device connected to sensors and actuators installed in each part of a plant, and a plurality of controls connected to the multiplex transmission device in a distributed manner. and a shared memory device connected to this control device, and each of the control devices refers to the plant automation sequence stored in the shared memory device and determines the target to be controlled and the control device itself.
The present invention is characterized in that each control device autonomously determines the start timing and performs plant automation in a distributed manner.

The shared memory device has information indicating an abnormality in each control device, and each control device can back up another control device that has become abnormal by referring to this information and the automation sequence. It is characterized by being configured as follows.

<<Operation>> A system is realized in which microprocessor-based control devices are distributed and automated without using a process computer.

Each control device refers to the automated sequence of the shared memory device and autonomously performs control. Backup is also taken into account in case the control device breaks down. Each control device autonomously performs control while referring to the automation sequence description.

The multiplex transmission device carries signals from all actuators and measuring instruments as sensors, and can be accessed by all control devices.

Therefore, it is possible to provide an economical and highly reliable distributed multiplexed plant automation system.

(Embodiment) An embodiment of the present invention will be described with reference to Figs. 1 and 2. In Fig. 1, measuring instruments 11 and actuators 12 as sensors and control devices 14 of each system are installed in each part of the plant. An optical multiplex transmission device 13 is connected between the measuring instrument 11 and actuator 12 and the control device 14, and a shared memory device 15 is connected to each control device 14.

The shared memory device 15 stores a control sequence 21 as shown in FIG. 2, a marker 22 indicating the current control status, and a fault control device list 23 indicating abnormal control devices. The shared memory 15 is a memory to which the information stored therein can be accessed by all connected devices 13. Each control device 14 accesses the shared memory device 15, reads the position of the marker 22 indicating the current state of the control sequence, and if the control next to the marker is the control assigned to it, executes it. When this is completed, the marker position is advanced by one.

Specifically, the above processing is performed as follows. The control sequence shown in FIG. 2 is specifically described in the shared memory device 15 in the following frame format.

Name Control 2 Next control Control 3 Previous control Control m”r Control content Control program 2 Precondition Precondition 1 Completion condition Completion condition 2 Responsible control device 2 Control device 1 Backup control I1 device: Control wJVt location 2 Current status:
“Under control” or “Completed” or “Ended” or “Unfinished” Here, “Name” is the name of the control, “Next control” is the control to be executed after this control is executed, “Control "Content" is the name of the computer program to implement this control, "
``Control device in charge'' describes the control device that executes this control, and ``Backup control device'' describes the control device that backs up the control device described in ``Control device in charge'' in case of failure. The "current state" includes the following items according to the operation of each control device (this corresponds to the above-mentioned marker).

(1) “Under control”... Indicates that this control is currently under control.

(2) "Complete"... Indicates that this control has just been transferred (this is written in the last control that has been completed so far).

(3) “End”... Indicates that this control has already ended.

(4) “Unfinished”: Indicates that this control is not yet finished.

Referring to the control sequence described above, each control device performs the following operations.

(1) Search for a frame in which the "current state" is "control middle" or "completed" and find out the control currently being performed or the last control that has been completed (hereinafter, this is referred to as the current control ).

(2) Refer to the frame that describes the current control and find out the next control in the control sequence by "next control".

(3) “Control device in charge” of the frame that describes the next control
By referring to , the control m+ device in charge of the next control is known.

(4) If the control device in charge of the next control is its own control 611 device, "preconditions" and "control program"
The controller knows the preconditions to be checked and the control program to be executed, and executes them when the "current state" of the previous control is completed.

(5) If the control device in charge of the next control is not its own control device, the “backup control device” determines whether or not it is the backup control device.

(6) If the control device itself is a backup control device, and if the control device listed in the “Control IA location in charge” is included in the malfunctioning control device list described later, it will be used as a backup control device (4). It works the same way.

(7) When checking the preconditions is started as the control device in charge or the backup control device, the “current state” of the control frame is set to “under control.”

(8) During execution of the control program, the II1 control device in charge or the backup control device checks the conditions described in the "completion condition" in the relevant control frame, and if this is satisfied, terminates the control program and “status” is considered complete.

(9) Furthermore, the control device refers to the "r-th control" in the control frame, and when the "current state" of the next -1 control becomes "under control", the control device refers to the "current state" of the control frame. ” from “completed” to “finished”.

In addition to the control sequence 22, the shared memory device 15 is provided with a malfunctioning control device list 23 indicating malfunctions of each control device 14. In addition to the aforementioned control operations, each control III device 14 has a self-diagnosis function consisting of a watchdog timer or an instruction test.

As a result, the occurrence of an abnormality is detected and registered in the malfunctioning control device list 23. Since the defective control device list 23 is on the shared memory, it can be accessed by other control devices, and the control device list 23 in which the defect has occurred can be accessed by other control devices.
You can know the VL position.

Furthermore, the multiplex signal transmission device 13 in FIG. 1 is arranged to transmit the signals of all the measuring instruments 11 and the signals of the actuators 12, so that any control wJ device can access any signal. This can be achieved using known transmission techniques such as time division multiplex transmission.

[Effects of the Invention] The plant automation system according to the present invention has the following effects.

(1) There is no need for a large process computer as in the past, and the system can be made smaller and lower in cost.

(2) A shared memory device only performs passive operations such as storing information, and does not perform active processing like conventional process combinations. Even if they are maintained, their reliability is higher than that of process computers. Also, multiplexing is easier and cheaper than using a process computer.

(3) The overall management and control of control sequences, which was conventionally performed by process computers, has been distributed to each control device and is now performed autonomously, so even if a control device malfunctions, the effect will be felt on the entire system. The control device can be used alone without any spread, and the overall control function will not be lost.

(4) Even if the TM control device breaks down, backup can be provided by another control device, and the overall reliability is high.

Therefore, the plant automation system according to the present invention contributes to improving the safety and reliability of plants such as nuclear power plants,
Great effects can be achieved.

Although frames are used to describe the control sequence in this embodiment, the description format is not limited to frames, and any description format may be used as long as it includes the information described here.

Further, although only a single backup is shown here as a backup, it is also possible to specify multiple backups.

[Brief explanation of the drawing]

FIG. 1 is a system diagram showing an embodiment of the plant automation system according to the present invention, FIG. 2 is a block diagram showing the storage contents of the shared memory device in FIG. 1, and FIG. 3 is a system diagram showing a conventional automation system. It is a diagram. 1, 11... Measuring instruments 2, 12... Actuators 3, 14... Control device 13... Optical multiplex transmission device 15... Shared memory device 21... Control sequence 22... Marker 23 ...List of malfunctioning control devices (, 8733) Agent: Yoshiaki Inomata, patent attorney
1 other person》- Figure Figure Figure ≧1

Claims (2)

[Claims] (1) From a multiplex transmission device connected to sensors and actuators installed in each part of the plant, multiple control devices distributed and connected to this multiplex transmission device, and a shared memory device connected to this control device. Each of the control devices refers to the plant automation sequence stored in the shared memory device and autonomously determines the target to be controlled and the control start timing, thereby distributing the plant automation. A plant automation system that is characterized by: (2) The shared memory device has information indicating an abnormality in each control device, and each control device is configured to back up another control device that has become abnormal by referring to the information and the automation sequence. 2. The plant automation system according to claim 1, wherein the plant automation system is configured as follows.