JPH04248798A - Decentralizing type controller - Google Patents

Abstract

PURPOSE:To offer the decentralizing controller with high reliability able to implement plant control without hindrance by backing up a central controller momentarily by a host controller even when a fault of the central controller takes place. CONSTITUTION:A local controller 6 is connected to a transmission line 3 as the same level as the collective controller 5, and a plant state input section and a plant monitor section having been provided to the collective controller 5 in a conventional device are transferred to the local controller 6 and the same control function as that of the collective controller 5 is provided to a host controller 2.

Description

[Detailed description of the invention]

[Object of the invention]

0002

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a distributed control system that controls the operation of a plant by giving startup commands and the like from a higher-level control unit to lower-level control units via transmission lines.

0003

BACKGROUND OF THE INVENTION Due to the recent rapid progress in LSI technology, microprocessor devices have been greatly improved, and small computers and microcomputers have become widespread. Along with this, reliability and
In order to improve costs and installation space, we are moving from centralized control systems using large computers in the electric power and power generation field.
There has been a shift to a distributed control system in which multiple small computers or microcomputers are used and distributed in each functional unit. This function-distributed control system realizes function distribution by connecting the upper-level computer and the lower-level computers that are divided for each function and controlled in a distributed manner through a data way.

FIG. 27 shows a general functionally distributed system. By selecting the operation timing control switch push button installed for each function on console 1,
The selection signal is transmitted from the upper control device 2 via a transmission path 3 such as a data way to the overall control device 5 that performs overall control in each function distributed control system 4 located at the lower level. The overall control device 5 determines the plant state based on the selection signal from the higher level and the process signal from the plant 7, and gives individual control commands to several local control devices 6 at the lower level. Based on this control command, the local control device 6 outputs operation signals to the plant 7 for operating valves, pumps, etc. according to predetermined operation logic. The overall control device 5 sends the current plant control state back to the higher-level control device 2 as a message. The higher-level control device 2 outputs the messages sent from the plurality of central control devices 5 to the console 1 as appropriate.

FIG. 28 shows the configuration of the above-mentioned distributed control device in more detail. The console 1 consists of pushbutton switches for controlling the operation timing for each function, and a display output device for outputting messages such as changes in plant status or alarms. an input section 20 that inputs a selection signal a of
, an output section 21 that receives signals from the lower-level functional distributed control system 4 and outputs them to the display output device on the console 1; and an output section 21 that receives a signal from the lower-level functional distributed control system 4 and outputs it to the display output device on the console 1; A transmission input/output unit 22 transmits and receives signals from the lower function distributed control system 4 to the output unit 21, and each integrated control device 5 receives plant status values input from the plant 7 via the transmission input/output unit 22. It is composed of a plant status value table 23 to be stored.

The overall control device 5 includes a lower transmission input/output section 50 that exchanges data between the overall control device 5 and the transmission line 3, a plant state input section 51 that inputs the process signal b from the plant 7, and a plant state input section 51 that inputs the process signal b from the plant 7. The process signal b is inputted from the section 51 to detect a change in the plant state and detect the change in the plant state.
A plant monitoring unit 52 outputs the alarm message output request signal c to the lower transmission input/output unit 50 for transmitting it to the upper control device 2, and outputs a status change signal d when a status change is detected.
, a plant status value table 53 that stores plant status values input by the plant monitoring unit 52 via the plant status input unit 51 , a control table 54 that stores plant operation control methods, and a selection signal from the console 1 . a,
A plant control unit 55 receives the status change signal d from the plant monitoring unit 52 and outputs a control command signal e to the local control device 6 and a message output request signal f to the console 1 according to the control contents stored in the control table 54. It consists of

[0007] The local control device 6 is a plant control unit 5
It has a logic sequence unit 60 that outputs an operation command signal g to the plant 7 based on the control command signal e from the plant 7 according to a predetermined operation logic.

In the distributed control device configured as described above, the selection signal a of the operation timing operation switch for each function on the console 1 is transmitted to the upper control device 2, the transmission path 3, and the lower transmission input/output section 50 of the central control device 5. The plant control unit 55 is notified through this. As a result, the plant control section 55
performs control processing based on the control table 54 and the plant state value table 53, and passes the control command signal e to the logic sequence section 60 of the local control device 6. The logic sequence unit 60 performs sequence processing of the operating end logic based on the control command signal e and outputs the operation command signal g to the plant 7.

On the other hand, when the plant monitoring section 52 detects a change in the plant state from the process signal b input from the plant 7, a state change signal d is output to the plant control section 55. The same control processing as in the case of the selection signal a is performed. Further, the message output request signal f from the plant control unit 55 is sent to the upper control unit 2 through the lower transmission input/output unit 50 and the transmission line 3.
The transmission input/output unit 22 of the console 1 is notified, and the information is output to the display output device of the console 1 via the output unit 21.

[0010] In this way, the integrated control device 5 of the distributed control device transmits plant status information to the upper level control unit 2, a selection signal from the higher level control unit 2 to the lower level, or a control command based on the plant status to the lower level. to the local control device 6, etc.
It is an important link between upper and lower control devices. Therefore, if the overall control device 5 breaks down for some reason, a serious situation will arise in which the plant cannot be monitored or controlled.

[0011]

[Problems to be Solved by the Invention] As described above, when a failure that causes the central control device 5, which is an important position in a distributed control device, to stop occurs, control becomes impossible, and the plant state that was being controlled is not controlled by the upper level control device. Since it is no longer possible to monitor using device 2, the operator has no choice but to go to the site and manually operate the device while checking the device status, or interrupt control.

The present invention has been made to address this problem, and even if a failure occurs in the central control device 5, the higher-level control device 2 can instantly back up the central control device 5 and continue plant control. It is an object of the present invention to provide a distributed control device capable of highly reliable plant control without causing any trouble.

[Configuration of the invention]

[0014]

[Means for Solving the Problems] To this end, the distributed control device of the present invention includes a higher-level control device that monitors and controls the entire plant, and a higher-level control device that controls individual devices within the plant based on commands from this higher-level control device. In a distributed control device that is equipped with local control devices, a central control device that centrally controls these local control devices for each function, and a transmission line that transmits data between a higher-level control device and a lower-level control device, local control is In addition to connecting the equipment to the transmission line, there is also a plant monitoring means that inputs plant status values from the plant to the local control unit and detects changes in the plant status, and a plant monitoring unit that detects changes in the plant status according to a predetermined operation logic based on control commands from the higher-level control unit. A logic sequence means for outputting operation commands to the plant is provided, and operator commands from the higher-level control device and status change detection signals from the plant monitoring means of the local control device are input to the central control device, and plant control commands are output. A fault detector is provided to detect a fault in the central control device, and a fault signal path is provided to transmit a fault signal from the fault detector to the higher-level control device. A plant control means with the same function as the plant control means in the system, and a higher-level control device that constantly monitors the status of the central control device based on failure signals and performs plant control in place of the central control device when a failure occurs in the central control device. and control device monitoring means for activating the plant control means.

[0015]

[Operation] In the distributed control device of the present invention, each local control device monitors the plant condition, and detects a change in the plant condition when the central control device is normal. In the case of a failure, the higher-level control device is notified via the transmission path. If the central control device is normal, timing operation commands from the higher-level control device by the operator and plant condition change detection signals from the local control device are transmitted to the central control device, and control commands for controlling the plant are responded to. Output to local controller. Based on this control command, the local control device outputs an operation command to the plant according to a predetermined operation logic. In addition, if the central control unit is abnormal, the installed fault detector will send a failure signal to the higher-level control unit via a dedicated failure signal path, and the higher-level control unit will act as a local controller instead of the failed central control unit. A plant condition change detection signal from a control device is input, and a control command for controlling the plant based on a timing operation command by an operator is output to a corresponding local control device.

[0016] In this way, even if the central control device should fail, the higher-level control device will immediately detect this and transmit data directly to the local control device via the transmission path, thereby backing up the failed central control device. Since the plant is controlled by the system, highly reliable plant control can be performed without interfering with plant monitoring and control.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In the figures, the same parts as in the conventional example are given the same reference numerals. FIG. 1 shows an embodiment of the distributed control device of the present invention. The difference in this figure from the conventional example shown in FIG. A fault signal path (hard wire) B is attached to notify the fault signal h from the device A to the host controller 2, and this fault signal h is input into the host controller 2 to detect a fault in the central controller 5. A control device abnormality determination unit 24 that detects a failure, a central control device management table 25 that inputs a failure detection signal from the control device abnormality determination unit 24 and always stores the current state of the central control device 5, and a configuration of lower control devices. A control device monitoring unit 27 that monitors the central control device 5 based on the control device configuration table 26 in which the control device is registered and the central control device management table 25 and issues a signal requesting plant control by the host control device 2 when a failure is detected; A plant control section 28 and a control table 29 having the same functions as the overall control device 5 which is activated by a request signal from the device monitoring section 27 are additionally provided. Furthermore, in order to enable data transmission between the upper control device 2 and the local control device 6, the local control device 6, which was controlled by the central control device 5, is connected to the transmission line 3, and the local control device 6 is connected to the local control device 6. In addition to providing a transmission input/output section 61, the local control device 6 can input and monitor plant status values that were previously performed by the central control device 5.
The plant status input section 62 and the plant monitoring section 63 are relocated from the central control device 5.

Therefore, the upper control device 2 in the distributed control device of this embodiment has an input section 20 for inputting timing operation command information from the operator from the console 1, and an input section 20 for inputting timing operation command information from the console 1 to the console 1 based on signals from the lower control device. an output section 21 that makes a display request to the host, a transmission input/output section 22 that exchanges data between the host control device 2 and the transmission line 3, and an input section 20 that exchanges signals between the output section 21 and the transmission input/output section 22. A control device monitoring unit 2 that relays information and requests plant control by the host control device 2 when an abnormality occurs in the central control device.
7, a plant control unit 28 that performs plant control in place of the central control unit 5 in accordance with a plant control request from the control unit monitoring unit 27, a control table 29 in which plant operation control methods are registered in advance, and a local control unit 6. a plant state value table 23 that stores plant state values input from the plant 7; a control device configuration table 26 in which the configurations of lower control devices are registered in advance; and a central control device 5.
A control device abnormality determination section 24 constantly monitors the failure of
The control device management table 25 stores the current status of abnormality/normality of the control device.

The overall control device 5 also includes a lower transmission input/output section 50 that exchanges data with the transmission path 3, and a plant status value table 53 that stores plant status values input from the plant 7 by the local control device 6. , local control is performed according to the control contents stored in the control table 54 by inputting a control table 54 in which plant operation control methods are registered in advance, a selection signal a from the console 1, and a plant state change signal d from the local control device 6. The local control device 6 includes a plant control unit 55 that outputs a control command signal e to the device 6 and/or a message output request signal f to the console 1, and a failure detector A that detects a failure of the central control device 5. A local transmission input/output unit 61 that exchanges data with the transmission path 3, a plant status input unit 62 that inputs the process signal b from the plant 7, and a plant status input unit 62 that constantly monitors the process signal b to detect changes in the status of the plant and determine the plant status. According to the operation logic predetermined by the plant monitoring unit 63 which outputs the change signal d and the plant status change/alarm message output request signal c to the console 1, and the control command signal e from the general control device 5 or the upper control device 2. Logic sequence unit 6 that issues an operation command signal g to the plant 7
It consists of 0.

Next, the operation of each of the above components will be explained in detail. As shown in the flowchart of FIG. 2, the input unit 20 of the host controller 2 inputs operator command information input from the console 1 (200), and determines whether this command information is a data display request or plant timing operation information. If it is a data display request, it outputs a data display request signal i having the plant point name number and output device number to be displayed to the output unit 21 (202). In the case of plant timing operation information, it is converted into a selection signal a consisting of the number of the corresponding central control device 5 and a control table index indicating which plant control is to be performed (2
03) and output to the control device monitoring unit 27 (204).

As shown in the flowchart of FIG. 3, the output unit 21 receives a display request from the console 1 (210).
, whether the display request is the message output request signal f from the plant control unit 28, 55 (211), the plant monitoring unit 6
Plant status change/warning message output request signal c from 3
(212) or a data request signal i from the operator from the input unit 20 (213). If the message output request signal f is the message output request signal f, the message Extracted from the message data area in the output section 21 with contents,
Output to the display device of console 1 (214). In the case of a plant status change/warning message output request signal c, the plant status value is extracted from the message data area in the output section 21 that has the point name and message content, based on the plant point name number and message number that the signal c has. Extract the plant status of the point from table 23 and output it to the display device of console 1 (2
15). In addition, in the case of a data display request signal i from an operator, the plant point name number and output device number input through the console 1 are used to extract data from the message data area in the output section 21 having the point name, and The plant state of the point is extracted from the state value table 23 and output to the display device of the console 1 (216).

The transmission input/output section 22 performs transmission processing for each integrated control device 5. Therefore, as shown in the flowchart of FIG. 4, the failure state of the central control device 5 is determined by the central control device management table 25, and the processing is divided into cases in which the central control device 5 is normal and cases in which the central control device 5 is in failure. The control device manages the transmission process (220). Also,
The transmission station numbers of the central control device 5 and local control devices 6-0 to 6-n for transmitting and receiving transmission data are determined for each central control device from the control device configuration table 26. It is assumed that the transmission station number of the control device 6 is extracted and used at any time.

First, when the overall control device 5 is in a normal state, the selection signal a of the console 1 input via the control device monitoring section 27 is transmitted to the lower transmission input/output section 50 of the overall control device 5 (221). The central control device 5 receives the message output request signal f transmitted from the lower transmission input/output unit 50 of the central control device 5 (222), and the local control device 6-0 to 6-n Plant status change/alarm message output request signal c and process signal b transmitted from local transmission input/output units 61-0 to 61-n of
receives the plant status value of f and sends a message output request signal f
The plant status change/warning message output request signal c is transmitted to the control device monitoring unit 27 (223), and the plant status value is set in the plant status value table 23 (224).

On the other hand, when the overall control device 5 is in an abnormal state,
When there is a failure notification request for the central control device 5 from the control device monitoring section 27, the central control device 5 is sent to the local transmission input/output sections 61-0 to 61-n of the local control devices 6-0 to 6-n.
sends a message that the device is out of order (225). Next, the control command signal e from the plant control unit 28 is converted into the control command e.
Based on the local control device number, which is the information of the local control device 6-0 to 6-n, transmission processing is performed to one of the local control devices 6-0 to 6-n (226). From the local control device 6, the local transmission input/output unit 61-0 of the local control devices 6-0 to 6-n
Receives the plant state change signal d, plant state change/alarm message output request c, and plant state value of the process signal b transmitted from ~61-n, and receives the plant state change signal d, plant state change/alarm message output request c is transmitted to the control device monitoring unit 27 (227), and the plant status value is set in the plant status value table 23 (228).
).

[0025] When the transmission processing for all the integrated control devices is completed in this manner, since the transmission processing is always performed, a time delay is performed and the next new transmission processing is started (229).

As shown in FIG.
~6-n plant status input units 62-0~62-n input the plant status values ST consisting of process signals b in the order of input.
It has areas Z0 to Zr for storing 0 to STm. In addition, these plant state values ST0 to ST
m has a plant point name identified within the distributed control device and a plant point name number that is a number arranged in order, and is arranged in the order of the central control device number ZZ0 to ZZn.
It stores plant status values for all integrated control devices. This table allows reading and writing of plant status values based on the overall control device number and plant point name number. By having such a plant status value table 23 in the host controller 2, the host controller 2 can monitor the plant state of the system.

As shown in the flowchart of FIG. 6, the control device abnormality determination unit 24 is a general control device that is notified through a failure notification hard wire B that connects the upper control device 2 and each general control device 5. 5 failures are constantly monitored (240)
If the status of the overall control device 5 is determined to be a failure, “1” is set in the area corresponding to the overall control device number in the overall control device management table 25 (241). After checking for abnormalities in all general control devices in this way,
A time delay is performed for constant monitoring (242), and failure checks are started for all integrated control devices from the beginning.

As shown in FIG. 7, the overall control device management table 25 has areas G0 to Gn corresponding to the presence of the overall control devices 5 in order of the overall control device number, and when the overall control device 5 is normal, the area is "0"; This is a table that stores the current state of the overall control device 5, which becomes "1" when an abnormality occurs.

As shown in FIG. 8, the control device configuration table 26 lists the central control devices 5 in the order of the central control device numbers in order to exchange data between the higher-level control device 2, the central control device 5, and the local control device 6. Transmission station number S and transmission station number T of the local control device 6 below it
This is a table in which U0 to Un of all integrated control devices are stored. In this way, this table 27 has
Since the transmission station numbers of the central control device 5 and local control devices 6 existing in the distributed control device are stored, the control device configurations of the central control device 5 and local control devices 6 can be known from this.

Since the control device monitoring section 27 executes processing for each central control device 5, as shown in the flowchart of FIG. 0 (270), the failure state of the central control device 5 is checked from the top of the table, and processing is performed separately for when the central control device 5 is normal and when it is in failure (271).

When the general control device 5 is in a normal state, the selection signal a from the console 1 is received from the input section 20 and passed to the transmission input/output section 22 (272), and the selection signal a from the transmission input/output section 22 is sent to the plant of the general control device 5. The message output request signal f from the control unit 55 or the plant status change/alarm message output request signal c from the plant monitoring unit 63 of the local control device 6 is passed to the output unit 21 (273).

When the central control device 5 is out of order, check the backup initial processing status stored in the control device monitoring unit 27 to see if the backup initial processing for the failed central control device 5 has been performed (274), and If the process has not been carried out, the transmission station number Uj of the failed central control device 5 is extracted from the control device configuration table 26 based on the central control device number j, and the transmission station numbers T0 to Tn of the local control device 6 are extracted from the control device configuration table 26. The local control device 6-0 ~ under the central control device 5 that has failed from
6-n is notified that the overall control device 5 has failed (275). As a result, the local control device 6-0~
6-n determines that the higher-level control device 2 is backing up the central control device 5, and transmits data such as control data between the higher-level control device 2 and the local control devices 6-0 to 6-n. Let's do it. Next, it is determined whether there is a request for plant control based on the selection signal a of the console 1 to the central control device 5 with the central control device number j or the plant status change signal d of the local control devices 6-0 to 6-n ( 2
76) If there is a request, start the plant control unit 28 using the central control device number j and the control table index which is the plant control request as the request parameters (277)
. This process is performed as required. In addition, the plant monitoring units 630 of the lower local control devices 6-0 to 6-n
The plant condition change/warning message output request signal c from ~63n is passed to the output unit 21 (278). When the control monitoring for all the overall control devices is completed in this way, a time delay is performed to establish a constant monitoring system, and the process returns to the initial execution (279).

As shown in the flowchart of FIG. 10, the plant control section 28 inputs the overall control device number j and the control table index, which are the request parameters from the control device monitoring section 27, and then inputs the control table index as shown in FIG. Select the control table Lj of the central control device corresponding to the central control device number j from the control table 29 as shown, obtain the pointer address from the pointer part PP using the control table index, and thereby control data M in the control table Lj. is taken out (280). Next, the conditions from the condition determination part X of the control data M to the condition determination end information XX are determined using the condition item Xa, condition sub-information Xb, and condition content Xc as one condition (281). To give a concrete example, condition 1 (
Xa1 (=0), Xb1, Xc1), condition 2 (X
a2 (=1), Xb2 , Xc2 ), condition 3 (Xa
3 (=2), Xb3 (=1), Xc3 ), the condition judgment is (Xc1 ) AND (Xc2
)OR(Xc3) and the result is Xb3 (=1)
When it matches, the condition is satisfied. When the condition is met (2
82), execution is moved to the process of operation content part Y (283
), the control item Ya, the control sub-information Yb, and the control content Yc of the operation content part Y of the control data M are taken as one operation content, and the control item Ya branches to each operation processing routine. If the control item Ya=0 (message output), a message output request signal f based on the output device number of the control sub-information Yb and the message number of the control content Yc is output to the output unit 20 (284). In the case of control item Ya=1 (activation of sequence processing of local control device 6), local control device 6- indicates the control command signal e based on the logic sequence number of control content Yc with the local control device number of control sub-information Yb. 0 to 6-n logic sequence section 60-0 to 6
Notify 0-n (285). The above operation process is carried out until the control content end information YY appears.

As described above, the configuration of the control table 29 is shown in FIG. 11. In this control table 29, there is a pointer part PP having pointer addresses P0 to Pn of control data M arranged in order of control table index, and control data M indicated by the pointer addresses P0 to Pn.
Control tables L0 to Ln for each integrated control device 5 are stored, each of which includes a control data section MM.

The control data M includes a condition judgment unit X, which is a description of conditions for determining whether it is time to execute plant control, and a sequence process of the operation logic of the local control device 6, which is executed when the condition of the condition judgment unit X is satisfied. Operation content section Y containing information such as startup and message output information for each operation.
Consisting of

The specific contents of the condition determination section X are as follows.
One condition is formed by the condition item Xa, the condition sub-information Xb, and the condition content Xc, and a determination is made using the conditions until the condition determination information XX appears. Condition item Xa: Specifies Boolean operations such as AND and OR for condition judgment. 0: -- (For the first condition) 1: AND 2: OR Condition sub-information Xb: Sub-information for condition determination. (The final condition of condition determination section X is valid) 0: When the result of condition determination is "0", the condition is established. 1: When the result of condition determination is "1", the condition is established. Condition details Xc: Point name indicating plant timing.

[0037] The specific contents of the operation content section Y are as follows.
The control content end information Y when the condition is satisfied in the condition determination section X above.
The processing of operation content Y is performed until Y appears. Control item Ya: Specification of control content Control sub-information Yb: Sub-information for operation processing (based on control item Ya) Control content Yc: Description of control content (based on control item Ya)
Control item Ya
Control sub information Yb Control content Yc
0: Message output…………Output device number……
...Message number 1: Local control device...Local control device...Logic sequence
Sequence processing start number
number.

From this control table 29, it is possible to determine which area in the control table L0 to Ln of the central control device is located based on the central control device number, and furthermore, control data M is extracted based on the pointer address P0 to Pn using the control table index. Therefore, by providing this table in the higher level control device 2 and giving the overall control device number and the control table index, it becomes possible to perform plant control that was performed by the overall control device 5.

Next, each component of the overall control device 5 will be explained. As shown in the flowchart of FIG. 12, the lower transmission input/output section 50 receives the selection signal a from the upper control device 2 and transmits it to the plant control section 55 (500). It also receives the plant state variation signal d and plant state value transmitted from the local control devices 6-0 to 6-n, and notifies the plant control unit 55 of the plant state variation signal d (50
1) The plant state value is set in the plant state value table 53 (502). On the other hand, the control command signal e from the plant control unit 55 is transmitted to one of the local control devices 6-0 to 6-n based on the local control device number which is the information of the control command signal e. Do (50
3). Furthermore, the message output request signal f from the plant control unit 55 is transmitted to the higher-level control device 2 (504). When the above processing is completed, a time delay is performed to perform constant transmission processing (505), and the execution returns to the initial processing.

As shown in FIG. 13, the plant state value table 53 of the central control device 5 is configured to locally control the plant state values ST0 to STm input by the local control devices 6-0 to 6-n under the central control device 5. Devices 6-0 to 6-n
It is composed of areas Z0 to Zr that are stored in the order of. The plant status values ST0 to STm have plant point names that are identified within the distributed control device, and since the plant point names correspond to plant point name numbers that are serially assigned internal numbers, they are identified by the plant point name numbers. It is possible to read and write plant status values ST0 to STm. As already explained, the plant status value table 23 of the host controller 2 is
The plant status value table 53 is collected in order of overall control device number.

The control table 54 of the central control device 5 is, as shown in FIG. Since they are the same, their explanation will be omitted.

The operation of the plant control section 55 of the central control device 5 is almost the same as that of the plant control section 28 of the host control device 2 shown in the flowchart in FIG. 10, and its explanation will be omitted.

[0043] The failure detector A is hardware that detects a failure when a failure occurs in the overall control device 5,
A failure signal h is sent to the higher-level control device 2 through a hard wire B connecting the higher-level control device 5 and the higher-level control device 2 to notify the higher-level control device 2 of a failure of the overall control device 5.

Next, each component of the local control device 6 will be explained. The logic sequence sections 60-0 to 60-n of the local control device 6 are activated by the local transmission input/output section 61 when a control command signal e is sent from the host control device 2 or the central control device 5. . Then, as shown in FIG. 15, a logic sequence is executed based on the logic sequence number of the control command signal e to determine the operation command signal g for operating the plant (600).
, and outputs this to the plant 7 (601).

Local transmission input/output sections 61-0 to 61-n
As shown in the flowchart of FIG. 16, the presence or absence of a failure notification of the central control device 5 from the higher-level control device 2 is stored,
Processing is performed separately when the central control device is normal and when it is malfunctioning (61
0).

When the overall control device 5 is normal, it transmits the plant status change/alarm message output request signal c and the plant status value from the plant monitoring unit 63 to the host controller 2 (
611), the plant status change signal d and the plant status value from the plant monitoring unit 63 are transmitted to the integrated control device 5 (61
2), receives the control command signal e from the overall control device 5 and notifies the logic sequence section 60 (613
).

If the overall control device 5 is out of order, the plant status change signal d from the plant monitoring unit 63, the plant status change/alarm message output request signal c, and the plant status value are all transmitted to the host controller 2. (614). It also receives a control command signal e from the host control device 2 and notifies it to the logic sequence unit 60 (615). When the series of processes described above is completed, a time delay is performed to perform constant transmission processing (616), and the process returns to the fault determination process of the overall control device.

As shown in FIG. 17, the plant status input unit 62 is activated at regular intervals by the plant monitoring unit 63, inputs process signals from the plant 7, and outputs them as plant status values to the plant monitoring unit 63 (620). ).

The plant monitoring sections 63-0 to 63-n, as shown in the flowchart of FIG.
is activated, the plant status input unit 62 takes in the plant status value input from the plant 7 (630), and passes it to the local transmission input/output unit 61 for transmission to the central control device 5 and higher-level control device 2 (631). . Compare the imported current plant state value with the previous stored plant state value (632), and if there is a change in the plant state,
The plant status change signal d converted from the plant status value to a control table index for requesting plant control is
It is output to the local transmission input/output unit 61 in order to transmit it to the higher-level control device 2 when the central control device 5 is out of order, and to the central control device 5 when the central control device 5 is normal (633). Furthermore, in order to request the output of a plant status change or alarm message, the plant point name number of the plant point where the plant status change or alarm occurred, the message number that is the index of the content of the message to be output, and the output device to which output device. The plant status change/warning message output request signal c having the output device number is output to the local transmission input/output unit 61 for transmission to the higher-level control device 2 (634). After a series of monitoring processes are completed, a time delay is performed to constantly monitor the plant (635), and the process returns to the initial activation of the plant status input unit 62.

In the distributed control device having the above configuration, the selection signal a of the console 1 is normally transmitted to the plant control device via the higher-level control device 2, the transmission path 3, and the lower-level transmission input/output section 50 of the central control device 5. The plant status change signal d detected by the plant monitoring unit 63 and transmitted to the plant monitoring unit 55 is transmitted to the local transmission input/output unit 61 of the local control device 6, the transmission path 3, and the central control device. The plant control unit 5 via the lower transmission input/output unit 50 of 5
5, the plant control unit 55 is activated,
A control command signal e is output based on the control table 54. This control command signal e is sent to the logic sequence section 60 through the transmission path 3 and the local transmission input/output section 61 of the local control device 6, and this control command signal e causes the logic sequence section 60 to control the plant 7 according to the operation logic.
Outputs the operation command signal g to.

The plant monitoring section 63 receives the plant condition change signal d.
At the same time, a plant condition change/alarm message output request signal c is output. 22 and the control device monitoring section 27 to the output section 21, and the output section 21 displays and outputs it to the display device of the console 1.

Furthermore, the plant control section 55 outputs a message output request signal f at the same time as outputting the control command signal e, and this message output request signal f is transmitted to the lower transmission input/output section 50, the transmission path 3, and the upper control device 2. It is sent to the output section 21 through the transmission input/output section 22 and the control device monitoring section 27,
The output unit 21 outputs the data to the display device of the console 1 for display.

Further, when a failure occurs in the central control device 5, the failure detector A of the central control device 5 detects the failure, and a failure signal h is sent through the hard wire B to indicate that the control device of the host control device 2 is abnormal. By sending the information to the judgment section 24, the control device abnormality judgment section 24 determines whether each integrated control device 5 is normal or not.
The overall control device management table 25 that stores abnormal conditions is updated. The control device monitoring unit 27 constantly monitors the overall control device management table 25, thereby controlling the overall control device 5.
failure can be detected. When the control device monitoring unit 27 detects a failure, in order to back up the failed central control device 4, it selects the transmission station numbers of the local control devices 6-0 to 6-n under the failed central control device 5 from the control device configuration table 26. Based on this, the local control devices 6-0 to 6-n under the faulty integrated control device 5 are notified that the integrated control device 5 has failed. As a result, the local control devices 6-0 to 6-n determine that the higher-level control device 2 is backing up the central control device 5, and the higher-level control device 2 and the local control devices 6-0 to 6-n
Data transmission such as control data is performed between the terminal and n. At the same time, the control device monitoring section 27 performs backup preprocessing of the overall control device 5, and when the backup preprocessing is completed, the control device monitoring section 27 can control the plant. Now, the selection signal a from the console 1 is sent to the control device monitoring section 27 through the input section 20 of the host control device 2.
The plant monitoring section 63 of the local control device 6 detects a change in the plant condition of the plant 7, and the outputted plant condition change signal d is sent to the local transmission input/output section 61 of the local control device 6 and the transmission line. 3. Transmission unit 2 of host controller 2
2 to the control device monitoring unit 27, the control device monitoring unit 27 performs the overall control using the general control device management table 25 in order to perform plant control using the higher-level control device 2 instead of the failed general control device 5. Control device number j and
The control table index based on the selection signal a of the console 1 or the plant state change signal d of the local control devices 6-0 to 6-n is notified to the plant control section 28 as a request parameter to issue a plant control request.

[0054] The plant control unit 28 has a general control device number j
control table 29 based on the control table index
The control table M that should be controlled more is taken out and the plant is controlled. The control command signal e is sent to the logic sequence section 60 through the transmission section 22 of the host control device 2, the transmission line 3, and the local transmission input/output section 61 of the local control device 6, and the logic sequence section 60 receives the control command signal e. An operation command signal g is output to the plant 7 according to the operation logic.

On the other hand, the message output request signal f issued by the plant control section 28 is displayed and outputted to the display device of the console 1 by the output section 21. Further, the plant status change/warning message output request signal c from the plant monitoring unit 63 is notified to the output unit 20 through the local transmission input/output unit 61, the transmission line 3, the transmission unit 22 of the upper control device 2, and the control device monitoring unit 27. The output unit 21 displays and outputs the data to the display device of the console 1.

Next, the operation when controlling the turbine of a thermal power plant using the distributed control device of the present invention will be described in detail with reference to FIGS. 19 to 26. In addition,
In these figures, parts corresponding to those already used in the description of the embodiments are designated by the same reference numerals. Distributed control devices in the field of thermal power generation include a boiler control system consisting of a boiler sequence control device, an automatic burner control device, and a boiler control device, a turbine control system consisting of a turbine sequence control device, a governor control device, and a BFP control device, and automatic synchronous control. Control of plant operation is achieved by connecting a functionally distributed lower-level control system, such as a generator control system consisting of automatic voltage control equipment and automatic voltage control equipment, to a higher-level control system via a transmission path such as a data way. It is being implemented.

Turbine control is performed by a turbine control system among the lower control systems and a higher-order control device 2 connected to the turbine control system via a transmission line 3, as shown in FIGS. 19 and 20. In the figure, the turbine control system is composed of a turbine integrated control device 5 that centrally controls the turbine control system, a turbine sequence control device 6-0 that is a local control device, a governor control device 6-1, and a BFP control device 6-2. has been done. In addition, the console 1 connected to the host controller 2 can display and output operation messages during plant control, changes in plant status, or plant warning messages accompanying changes in plant status, and can also display and output optional messages for the entire plant 7. The CRT1a can display plant status values by specifying plant points by the operator, and the thermal power plant starts with seawater system startup, cleanup, ignition preparation, ignition, temperature rise, turbine startup, annexation... The console device 1b has control selection switches for each breakpoint divided into major events such as 1 and 2 arranged in accordance with the startup procedure.

The turbine control system occupies an important position when starting and stopping a thermal power plant, and here, the operation when starting the turbine will be explained. In addition, FIG. 19 clearly shows the flow of data signals when the overall control device 5 is normal, and FIG. In these figures, the solid line of the data signal path shows the case where it is operating, and the broken line shows the case where it is not operating.

Typical turbine startup is, for example, when the regulator valve warming is completed and the main steam pressure at the turbine inlet is 774 k.
g/cm2 and the first stage inner metal temperature ≧150°C, the turbine startup preparation is completed, and a message indicating that the turbine startup preparation is complete is displayed on the CRT 1a on the console 1 to notify the operator. Ru. After confirming that the turbine start preparation is complete with the turbine start completion message displayed on the CRT 1a, the operator selects the turbine start breakpoint control selection switch on the console device 1b of the console 1 to set the turbine start conditions. are all established and the CRT of console 1
A message to start the turbine is displayed and output to 1a, and the speed increase rate is set to the target rotation speed of the turbine in the governor control device 6-1. The governor control device performs governor control on the turbine at a set speed increase rate to increase the turbine rotation speed.

Regarding such turbine startup, starting from the input of the plant status, the plant monitoring unit 6 is input via the plant status input unit 62-1 of the governor control device 6-1.
In step 3-1, the plant state is input, and plant state data of control valve warming, turbine inlet main steam pressure, and first stage metal temperature, which will be described below, is created. Control valve warming is performed when the turbine inlet main steam temperature >28
The MSV bypass valve is opened and closed at 0 °C and the furnace water cooling wall outlet temperature > 380 °C, and completion is completed when the temperature of the outer surface metal of the regulator is 230 °C or higher. When the temperature of this regulator valve warming is completed at plant point SSS00, it is set to "1". , when incomplete “
The turbine inlet main steam pressure is recorded as 0 when the turbine inlet main steam pressure is ≦74 kg/cm2 and the plant state value is stored in the plant point AAA00, and in another point SSS01. Record the plant state that is 1 in cm2.The first stage metal temperature is at the plant point AAA01.
and store the plant state value at another plant point SSS02 when the first stage metal temperature is <150 °C.
, record the plant state that becomes 1 when the first stage metal temperature is ≧150°C.

The plant status values AAA00, AAA01 and the plant status SSS00, SSS01, SSS02 created by the plant monitoring unit 63-1 are periodically transmitted to the lower transmission input/output of the turbine integrated control device 5 through the transmission line 3. unit 50 and the transmission input/output unit 22 of the upper control device 2
are transmitted to the plant status value tables 53 and 2, respectively.
3 will be updated and saved.

Here, as shown in the plant state value tables 53 and 23 in FIGS. 21 and 22, respectively, the current plant state is changed to the SSS state after the control valve warming is completed.
00=1 state, turbine inlet main steam pressure 70kg/c
m2, the state of AAA00=70, SSS01=0,
First stage metal temperature 170℃, AAA01=170
, SSS02=1 and the turbine startup preparation has not been established. Below, we will explain the operation of the control system at the time of turbine startup when the turbine integrated control device 5 shown in FIG. 19 is normal, as shown in FIG. explain.

Plant monitoring section 6 of governor control device 6-1
3-1 monitors the turbine inlet main steam pressure input by the plant status input section 62-1, and when the turbine inlet main steam pressure becomes >74 kg/cm2, SSS01=1.
At the same time, the main steam pressure at the turbine inlet is 74 kg/c.
m2, the control table index (=1) for requesting plant control is obtained, and this is used as the plant state variable signal d to control the local transmission input/output section 61-1, transmission line 3, and turbine integrated control device 5. Lower transmission input/output section 5
0 to the plant control unit 55.

The plant control unit 55 uses the control table index (=1), which is the plant state change signal d, to
Obtain the pointer address "40" of the control table from the control table 54 shown in FIG. The conditions for X are determined as follows. The conditional expression is (SS
S00) AND (SSS01) AND (SSS02), and by applying the plant status value to this, (1) A
ND(1) AND(1) becomes ="1".

In this way, the result of the condition determination section
”, and the condition sub-information of the condition determination section Therefore, the output device number of the CRT 1a on the console 1 of the control sub information Yb is "1", and the message number of "Turbine start preparation complete" of the control content Yc is "1".
00'', the lower transmission input/output section 50 and the transmission input/output section 2 of the upper control device 2 output the message output request signal f.
2. Notify the output unit 21 through the control device monitoring unit 27.

The output section 21 of the upper control device 2 outputs the message number "100" of the message output request signal f.
Extract the message content from the message data area in 1, and output the output device number of the message output request signal f.
The message "Turbine start-up ready" is displayed on the CRT 1a on the console 1.

The operator confirms the message "Turbine Startup Ready" displayed on the CRT 1a on the console 1, and issues a timing command for the next plant operation, ie, turbine startup, on the console device 1b of the console 1. It is input to the input unit 20 by selecting the control selection switch for the breakpoint of turbine startup.

The input unit 21 inputs the overall control device number "1" indicating that the turbine general control device 5 is to control the plant based on the timing command by selecting the control selection switch of the turbine start break point, and the turbine start break point. A selection signal a consisting of the control table index "2" of the control table corresponding to the selection of the control selection switch of the point is output to the control device monitoring section 27.

The control device monitoring section 27 constantly monitors the lower control devices by checking the failure state of the turbine integrated control device 5 in the overall control device management table 25. In this case, since the turbine integrated control device 5 has not failed, the selection signal a of the input section 21 is transmitted to the input/output section 2.
2. Transmit to the plant control section 55 through the transmission line 3 and the lower transmission input/output section 50 of the turbine integrated control device 5.

The plant control unit 55 selects the control table pointer address "60" from the control table 54 of FIG. 23 based on the control table index (=2) of the selection signal a.
”, extracts the control data M2, extracts the plant status value from the plant status value table 53, and determines the condition of the condition determination unit X as follows.The conditional expression is (SS
S00) AND (SSS01) AND (SSS02), and by applying the plant status value to this, (1) AN
D(1) AND(1) becomes ="1".

Since the result of the condition determination section X is "1" and the condition sub-information of the condition determination section X is "1", the condition is established, so the process moves to the operation content section Y of the control data M2.

Since the control item Ya of the first operation content in the operation content section Y is "0" (message output), the output device number of the CRT 1a on the console 1 in the control sub information Yb is "0" (message output).
1” and the message number of “Turbine startup start” of control content Yc is “101”, the message output request signal f
The data is transmitted to the output section 21 through the lower transmission input/output section 50, the transmission input/output section 22 of the upper control device 2, and the control device monitoring section 27.

The output section 21 of the higher-level control device 2 extracts the message content from the message data area contained in the output section 21 with the message number "101" of the message output request signal f, and extracts the message content from the message data area of the message output request signal f. A message "Turbine startup start" is displayed and output on the CRT 1a on the console 1 corresponding to the output device number "1" which is the information.

Furthermore, since the control item Ya of the second operation content in the operation content field Y is "1" (starting sequence processing of the local control device), the local control which is the governor control device 6-1 of the control sub information Yb is A control command signal e consisting of a device number "1" and a logic sequence number "10" for activating the logic for setting the speed increase rate up to the target rotation speed of the turbine of the control content Yc is output to the lower transmission input/output unit 50. The lower transmission input/output section 50 transmits the control command signal e from the plant control section 55 to the local transmission input/output section 61 of the governor control device 6-1 whose local control device number is "1".
-1. Since there is no failure notification of the turbine general control device 5, the local transmission input/output section 61-1 sends the control command signal e from the turbine general control device 5 to the logic sequence section 60-1.

The logic sequence unit 60-1 executes the speed increase rate setting logic up to the turbine target rotation speed based on the logic sequence number "10" which is the control command signal e, and generates the operation command signal g for increasing the turbine rotation speed. is output to plant 7.

Next, the operation of starting the turbine when the turbine integrated control device 5 shown in FIG. 20 fails will be explained. When a failure occurs in the turbine general control device 5, the failure detector A in the turbine general control device 5 detects the failure, and the fault detector A in the turbine general control device 5 detects the failure, and the fault detector A in the turbine general control device 5 detects the failure. Control device abnormality determination unit 24
A failure signal h indicating a failure of the turbine integrated control device 5 is transmitted to the turbine integrated control device 5.

The control device abnormality determination unit 24 writes “1” based on the overall control device number “1” that the failure signal h has. The overall control device management table 25 at this time is as shown in FIG.

The control device monitoring unit 27 constantly checks the overall control device management table 25, and when it detects a failure in the turbine overall control device 5 with the overall control device number “1” from the overall control device management table 25. , it is determined whether or not the backup initial processing for the failed turbine integrated control device 5 has been performed by checking the backup initial processing status stored in the control device monitoring unit 27 . If it is determined that the initial processing has not been performed, the central control device number “
1'', the turbine sequence control device 6-0, governor control device 6-1, and BFP control device 6 of the failed turbine general control device 5 and its subordinate local control devices are determined from the control device configuration table 26 of FIG. -2 respective transmission station numbers “20”, “21”, “22”
, "23" from the station number table U1, and based on the transmission station numbers "21", "22", and "23" of the local control devices 6-0 to 6-2 therein, the local control device 6- 0 to 6-2 are notified that the turbine integrated control device 5 has failed. As a result, the local control devices 6-0 to 6-2 determine that the higher-level control device 2 is backing up the turbine integrated control device 5, and the higher-level control device 2 and the local control devices 6-0 to 6-2
-2 becomes possible to transmit data such as control data, etc., and the backup preprocessing of the turbine integrated control device 5 by the control device monitoring unit 27 is completed.

As a result, the plant monitoring section 63-1 of the governor control device 6-1 determines that the turbine inlet main steam pressure inputted at the plant status input section 62-1 is >74 kg/cm2.
When this happens, set SSS01=1 and set the control table index (=1) for requesting plant control.
) and the information on the overall control device number “1” are sent to the plant through the local transmission input/output section 61-1, the transmission line 3, the transmission input/output section 22 of the upper control device 2, and the control device monitoring section 27. It is transmitted to the control unit 28. The plant control unit 28 selects the turbine integrated control device 5 based on the integrated control device number “1” in the control table 29 shown in FIG.
selects the control table L1, obtains the pointer address "40" from the pointer section PP using the control table index "1", and extracts the control data M1,
The plant status value is taken out from the plant status value table 23, and the condition determination unit X makes a determination as follows, similar to when the turbine integrated control device 5 is normal. The conditional expression is (SSS00
)AND(SSS01)AND(SSS02),
When the plant state value is applied to this, it becomes (1) AND (1) AND (1), and becomes = "1".

Since the result of the condition determination section X is "1" and the condition sub-information of the condition determination section X is "1", the condition is established, so the process moves to the operation content section Y of the control data M1. Since the control item Ya of the operation content section Y is "0" (message output), the CRT on the console 1 of the control sub information Yb
Based on the output device number "1" which is 1a and the message number "100" which indicates "Turbine startup preparation complete" which is the control content Yc, it is outputted to the output unit 21 as a message output request signal f.

The output unit 21 outputs a message output request signal f
The message content is extracted from the message data area in the output unit 21 using the message number "100",
A message "Turbine start preparation complete" is displayed and output on the CRT 1a on the console 1, which is the output device number "1" of the message output request signal f.

The operator confirms the message "Turbine Startup Ready" displayed on the CRT 1a on the console 1, and issues a timing command for the next plant operation, ie, turbine startup, on the console device 1b of the console 1. It is input to the input unit 20 by selecting the control selection switch for the breakpoint of turbine startup.

The input section 21 outputs a selection signal a consisting of the overall control device number "1" and the control table index "2" to the control device monitoring section 27 in the same way as when the turbine integrated control device 5 is normal. When the control device monitoring unit 27 determines that the turbine integrated control device 5 corresponding to the overall control device number “1” of the selection signal a is in failure based on the overall control device management table 25, it transmits the selection signal a to the plant control unit 28. .

The plant control unit 28 selects the control table pointer address "60" from the control table 29 of FIG. 26 based on the control table index (=2) of the selection signal a.
” is obtained, the control table M2 is taken out, the plant state value is taken out from the plant state value table 23, and the condition judgment section X makes the same judgment as when the turbine integrated control device 5 is normal as follows. (SSS00)AN
D (SSS01) AND (SSS02), and applying the plant status value to this results in (1) AND (1) AND (1), so = “1”
becomes.

Since the result of the condition determination section X is "1" and the condition sub-information of the condition determination section X is "1", the condition is satisfied, and the process moves to the operation content section Y of the control table M2. The control item Ya of the first operation content in the operation content section Y is “0”
(Message output) Therefore, the output device number of the CRT 1a on the console 1 of the control sub information Yb is "1" and the message number of "Turbine startup start" of the control content Yc is "101".
”, the output unit 21 outputs it as a message output request signal f.
Output to.

The output unit 21 outputs a message output request signal f
The message content is extracted from the message data area in the output section 21 using the message number "101",
CRT1a on console 1 corresponding to output device number "1" which is another information of message output request signal f
The message “Turbine startup started” is displayed and output.

Furthermore, since the control item Ya of the second operation content in the operation content section Y is "1" (starting sequence processing of the local control device), the plant control unit 28 controls the governor control device 6- of the control sub-information Yb. The input/output unit 22 transmits a control command signal e consisting of a local control device number “1”, which is 1, and a logic sequence number “10” that starts a logic that sets the speed increase rate to the target rotation speed of the turbine of control content Yc. Output to. The transmission input/output section 22 transmits the control command signal e from the plant control section 28 to the local transmission input/output section 61-1 of the governor control device 6-1 whose local control device number is "1" through the transmission line 3. The local transmission input/output section 61-1 notifies the logic sequence section 60-1 of the control command signal e from the host control device 2 in processing when the turbine integrated control device 5 fails.

The logics sequence unit 60-1 executes the speed increase rate setting logic up to the turbine target rotation speed with the logic sequence number “10” which is the control command signal e, and generates an operation command signal for increasing the turbine rotation speed. g is output to plant 7.

In this way, in the distributed control device of the present invention, the local control device 6 is connected to the transmission line 3 at the same level as the central control device 5, and the plant status input section and the plant By relocating the monitoring unit to the local control device 6, data transmission between the higher-level control device 2 and the lower-level local control device 6 becomes possible. However, it is now possible to directly monitor by transmitting data from the local control device 6 without going through the central control device 5. Further, by providing the higher-level control device 2 with the control function of the overall control device 5, even if the overall control device 5 breaks down, the higher-level control device 2 can continue monitoring and controlling the plant state without any problem.

[0090]

As explained above, according to the present invention, even if a failure occurs in the central control device, the higher-level control device can instantly back up the central control device.
It is possible to prevent any interference with control, and therefore, highly reliable plant control is possible, and the plant can be operated safely.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an embodiment of a distributed control device of the present invention.

FIG. 2 is a flow diagram illustrating the operation of the input section 20.

FIG. 3 is a flow diagram illustrating the operation of the output section 21.

FIG. 4 is a flow diagram illustrating the operation of the transmission input/output unit 22.

FIG. 5 is a diagram showing the configuration of a plant status value table 23.

FIG. 6 is a flow diagram illustrating the operation of the control device abnormality determination section 24.

FIG. 7 is a diagram showing the configuration of an overall control device management table 25. FIG.

8 is a diagram showing the configuration of a control device configuration table 26. FIG.

FIG. 9 is a flow diagram illustrating the operation of the control device monitoring section 27.

FIG. 10 is a flow diagram illustrating the operation of the plant control section 28.

FIG. 11 is a diagram showing the configuration of a control table 29. FIG.

FIG. 12 is a flow diagram illustrating the operation of the lower transmission input/output unit 50.

FIG. 13 is a diagram showing the configuration of a plant status value table 53.

FIG. 14 is a diagram showing the configuration of a control table 54. FIG.

FIG. 15 is a flow diagram illustrating the operation of the logic sequence section 60.

FIG. 16 is a flow diagram illustrating the operation of the local transmission input/output unit 61.

FIG. 17 is a flow diagram illustrating the operation of the plant status input section 62.

FIG. 18 is a flow diagram illustrating the operation of the plant monitoring section 63.

FIG. 19 is a block diagram showing the flow of signals between control devices when the turbine integrated control device 5 according to the present invention is normal.

FIG. 20 is a block diagram showing the flow of signals between control devices when the turbine integrated control device 5 according to the present invention has an abnormality.

FIG. 21 is a diagram showing an example of part of the contents of a plant status value table 53.

FIG. 22 is a diagram showing an example of part of the contents of the plant status value table 23;

FIG. 23 is a diagram showing an example of part of the contents of the control table 54;

FIG. 24 is a diagram showing an example of part of the contents of the overall control device management table 25.

FIG. 25 is a diagram showing an example of part of the contents of the control device configuration table 26;

FIG. 26 is a diagram showing an example of part of the contents of the control table 29;

FIG. 27 is a block diagram showing an overview of a conventional distributed control device.

FIG. 28 is a block diagram showing the configuration of a conventional distributed control device.

[Explanation of symbols]

1......Console 2... Upper control device 3……Transmission line 4...Functional distributed control system 5... General control device 6...Local control device 7……Plant 20……Input section 21……Output section 22...Transmission input/output section 23...Plant status value table 24...Control device abnormality determination section 25……General control device management table 26...Control device configuration table 27...Control device monitoring section 28...Plant control section 29……Control table 50……lower transmission input/output section 53……Plant status value table 54……Control table 55……Plant control section 60……Logic sequence section 61...Local transmission input/output section 62...Plant status input section 63……Plant monitoring department A...fault detector B……Hard wire (failure signal path)

Claims (1)

[Claims] [Claim 1] A higher-level control device that monitors and controls the entire plant, a local control device that controls individual devices in the plant based on commands from the higher-level control device, and an integrated control of these local control devices for each function. In a distributed control device, the distributed control device includes a central control device that performs data transmission, and a transmission line that performs data transmission between the higher-level control device and the lower-level control device,
The local control device is connected to the transmission path, and a plant monitoring means is configured to input a plant state value from the plant to the local control device to detect a change in the plant state, and a plant monitoring means is configured to connect the local control device to the transmission path, and to detect a change in the plant state by inputting a plant state value from the plant to the local control device. and a logic sequence means for outputting operation commands to the plant according to the operation logic determined by the controller, and a logic sequence means for outputting operation commands to the plant according to the operation logic determined by the controller, and transmitting operator commands from the higher-level control device and status change detection signals from the plant monitoring means of the local control device to the central control device. A plant control means for inputting and outputting plant control commands, a fault detector for detecting a fault in the central control device, and a fault signal path for transmitting a fault signal from the fault detector to the upper control device are provided. The higher-level control device includes a plant control means having the same plant control function as the general control device, and a system that constantly monitors the status of the general control device based on the failure signal and, when a failure occurs in the general control device, A distributed control device comprising: a control device monitoring means for activating the plant control means of the host control device to perform plant control on behalf of the host control device.