JP2002014703A - Plant controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a plant controller highly reliable and compact. SOLUTION: This plant controller which controls the operations of various devices disposed in a plant is equipped with a digital controller 1 equipped with a central processor which computes two commands, i.e., a device control command for placing various devices in operation manually by a plant operator and automatically according to logic previously stored in the plant controller and a device protection command for protecting various devices when a signal showing abnormality of the devices or plant is received and a PLD-based controller 6 equipped with a PLD computing only the device protection command; and a means which computes the device protection command is doubled by the digital controller and PLD-based controller.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plant control device for controlling the operation of various devices arranged in a plant.

[0002]

2. Description of the Related Art Conventionally, a plant control device for controlling the operation of various devices arranged in a plant has conventionally been a hard wired logic which uses a hard relay, a solid state timer to form a logic, or a CPU (central control device). And a digital controller that constitutes logic. Further, in recent years, widespread automation of plant operation has been promoted to save labor for plant operators, and accordingly, the number of devices to be controlled by the plant control device has been increasing.

For this reason, plant control devices tend to be sophisticated and complicated. However, when logic is constituted by hard-wired logic, a large number of hard relays and solid state timers are required, the number of wirings becomes enormous, and the cost and cost are increased. In recent years, due to the poor space factor, the fact that digital controllers with CPUs have been adopted in control devices of various plants and are operating normally, and the price of digital controllers has become cheaper than before, Most functions of the plant control device are realized by a digital controller.

However, when a logic is formed by a digital controller, the number of parts used is much larger than that of a hard-wired logic, so that the reliability is inferior to that of a hard-wired logic. In addition, due to economic reasons and space factors, a single controller controls multiple devices by time-division processing. In the event of a digital controller failure, multiple devices cannot be controlled, and the impact on the plant is hard wired logic. It is larger than at the time of failure.

For this reason, in a plant control device, a circuit (hereinafter, referred to as a device) for ensuring the safety of the device by forcibly stopping the device or closing a valve in a situation where the device in the plant may be damaged. (Referred to as protection circuit)
However, if the device protection circuit is configured with a digital controller, it is impossible to ensure the safety of the device in the event of a CPU failure, so conventionally, the device protection circuit is configured with hard-wired logic. I was

FIG. 7 shows a system configuration of a conventional plant control device. In FIG. 7, reference numeral 1 denotes a digital controller, which is used to perform an operation of operating equipment by manual operation of a plant operator and an operation of automatically operating equipment in accordance with a logic stored in advance by a process signal input indicating a state of a plant. A control circuit 11 constituting a logic is provided. 2 is hardwired logic,
Here, a device protection circuit 21 is provided.

Further, a logical OR logic 72 of a device control command 41 of the digital controller which is a device operation command from the control circuit 11 and a device protection command 41 of a hard wired logic which is a device operation command from the device protection circuit 21 is hard wired. A device operation command 43, which is configured by logic 2 and is the result of the calculation, is an operation command to the device. The plant 3 is controlled by opening / closing the motor-operated valve 31 and starting / stopping the fan 32 and the pump 33 according to the device operation command 43.

FIG. 8 is a detailed diagram of the logic formed inside the conventional plant control device shown in FIG. or,
FIG. 8 shows the logic of one pump among the logics configured inside the conventional plant control device. The logic within the dotted line in FIG. 8 indicates the logic 8 configured inside the plant control device, the logic within the dashed line indicates the logic 81 configured inside the digital controller, and the logic within the two-dot chain line indicates the hardware. The logic 82 constituted by wired logic is shown.

The logic shown in FIG. 8 is described by a logical product logic 71, a logical sum logic 72, and a logical negation logic 73. 8, an automatic mode selection switch 91, a manual mode selection switch 92, and a start switch 9
3. The stop switch 94 is a switch for the operator of the plant to operate, and the automatic mode selection switch 9
1. The operator of the plant selects the operation mode of the equipment by the manual mode selection switch 92.

When the starting condition 95 is satisfied according to the state of the plant while the automatic mode is selected,
If the start condition 55 of the automatic mode is satisfied and the stop condition 96 is satisfied depending on the state of the plant while the automatic mode is selected, the stop command 57 of the automatic mode is satisfied.

When the start switch 93 is pressed by the plant operator while the manual mode is selected, the start command 56 for the manual mode is established. When the manual mode is selected, the plant operator issues a command. Stop switch 9
When 4 is pressed, the stop command 58 in the manual mode is established.

When one of the automatic mode start command 55 and the manual mode start command 56 is satisfied,
Start command 51 of the control circuit inside the digital controller
Holds, and the command is output from the digital controller 1 to the hard wired logic 2.

On the other hand, if either the stop command 57 in the automatic mode or the stop command 58 in the manual mode is satisfied, the stop command 52 of the control circuit inside the digital controller is satisfied, and the command is issued to the digital controller 81 (FIG. 7). 1) is output to the hard wired logic 82 (2 in FIG. 7).

The circuit constituting the logic for creating a start / stop command for the equipment installed in the plant in the above-described automatic mode and manual mode is called a control circuit 11 shown in FIG. The start command 51 of the control circuit inside the digital controller and the stop command 52 of the control circuit inside the digital controller are input to the hard wired logic 2, and the start command 51 of the control circuit inside the digital controller is sent to the pump 33 as a start command 53. Is output.

On the other hand, in the hard wired logic 2,
A logic that satisfies the forced stop condition 97 when an abnormality of the equipment or an abnormality of the plant is detected is configured (a circuit configuring this logic is called an equipment protection circuit 21). When the forced stop condition 97 is satisfied, the hard wired logic device protection command 47 is satisfied.

One of the stop command 52 for the control circuit inside the digital controller, which is input from the digital controller 1 to the hard wired logic 2, and the equipment protection command 47 for the hard wired logic,
Alternatively, when both are satisfied, the stop command 54 is output to the pump 33. FIG. 8 describes the logic of the pump. However, the logic is the same for the fan 32, and only the start / stop of the motor-operated valve 31 is changed to open / close. The logic is the same as that of FIG. is there.

[0017]

In the above-mentioned conventional plant control system, a digital controller is used as control means. Recently, the application range of the digital controller has been expanded to improve the cost and the space factor, but the reliability of the digital controller alone is inferior to that of the hard wired logic.

Therefore, a device protection circuit requiring a high degree of reliability has been constituted by hard-wired logic because a large number of devices cannot be controlled when the digital controller fails. Also, since the equipment protection circuit is configured by hard wired logic for each equipment installed in the plant, many hard relays,
A solid-state timer and wiring were required, and this was a factor that hindered the downsizing and cost reduction of the plant control system.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide a plant control apparatus having high reliability and realizing a more compact system than a conventional plant control system.

[0020]

According to a first aspect of the present invention, there is provided a plant control apparatus for controlling the operation of various devices arranged in a plant. A device control command for performing an operation by manual operation of a worker and an operation by automatic operation according to a logic stored in the plant control device in advance by a process signal input indicating a state of the plant, and an abnormality of the various devices or a plant A digital controller including a central processing unit that calculates the two commands, that is, a device protection command for performing an operation of protecting the various devices when receiving a signal indicating an abnormality, and calculates only the device protection command PLD (Programmable)
a PLD-based controller having an eLogic Device), wherein the means for calculating the device protection command is duplicated by the digital controller and the PLD-based controller.

Therefore, by duplicating the means for calculating the equipment protection command between the digital controller and the PLD-based controller, a plant control device having high reliability and realizing a more compact system than the conventional plant control system is provided. It is possible to do.

According to a second aspect of the present invention, in the plant control apparatus according to the first aspect, a logical sum of a device protection command from the digital controller and a device protection command from the PLD-based controller is calculated by the various types. Directive for protection of equipment for other devices.

According to a third aspect of the present invention, in the plant control apparatus according to the first aspect, the logical product of the equipment protection command from the digital controller and the equipment protection command from the PLD-based controller is used for each of the various types. Directive for protection of equipment for other devices.

According to a fourth aspect of the present invention, in the plant control apparatus according to the first aspect, a digital controller including a CPU for calculating the device control command and the device protection command, and a digital controller including only the device protection command. A PLD-based controller having a PLD for calculating, and a transmission system forming a signal transmission path between the digital controller and the PLD-based controller, and a device control command and a device protection command calculated by the digital controller. Is transmitted to a PLD-based controller through a transmission system, thereby generating a device operation command from the device control command and the device protection command calculated by the digital controller, and a device operation command from the device protection command calculated by the PLD-based controller. Inside the PLD based controller Configuration was.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) (corresponding to [Claim 1]) FIG. 1 is a block diagram showing a first embodiment. Figure 1
In FIG. 7, the same functional portions as those in FIG. The configuration of this embodiment is characterized in that the digital controller 1 has a conventional control circuit 1.
In addition to the above, a device protection circuit 12 is provided, and a logic operation is performed by a CPU board, which will be described later, and the resulting command to each device disposed in the plant, such as the motor-operated valve 31, the fan 32, the pump 33, is transmitted to a digital controller. Output as an output signal 50.

On the other hand, a PLD-based controller 6 is newly provided, the logic of the device protection circuit 61 is calculated, and the result is output as a device protection command 44 from the PLD-based controller 6. Then, the digital controller output signal 50 and the device protection command 44 of the PLD-based controller are input to the duplex output circuit 20.

The dual output circuit 20 performs a process of creating a device operation command 43 from the digital controller output signal 50 as an input and the device protection command 44 of the PLD-based controller. Becomes an operation command to the device. Then, the electric valve 31 is opened and closed, the fan 32, the pump 3
Control of the plant 3 is performed by starting and stopping the plant 3.

FIG. 2 shows a hardware configuration of the PLD-based controller 6. In FIG. 2, reference numeral 62 denotes a PLD for a device protection circuit, and the device protection circuit 6 shown in FIG.
The operation of the logic 1 is performed by the PLD 62 for the device protection circuit. Further, the PLD based controller 6
Is provided with a variable timer PLD 63, and a device protection circuit including timer logic can be configured by the PLD-based controller 6.

Reference numeral 64 denotes an input circuit for inputting the equipment protection circuit input signal 48 to the equipment protection circuit PLD 62. Reference numeral 65 denotes an output from the equipment protection circuit PLD 62 as a PL.
This is an output circuit for outputting as a device protection command 44 of the D-based controller. Since the hardware configuration is thus simple, the hardware of the PLD-based controller 6 can be realized on a single board.

Further, the PLD-based controller 6 has high reliability because the number of parts used is small. When the PLD-based controller 6 is applied to a plant control device to configure the device protection circuit 61, the device protection circuit 61 of about 1 to 5 devices can be configured on a single substrate. The protection circuit of the equipment in the plant is configured using the substrate.

However, in the PLD-based controller 6 in which the system is composed of a plurality of boards,
The D-based controller 6 stores the logic for each board, and each board can perform the logic operation independently of the other boards and output the result. Therefore, when a failure occurs in one board, In this case, it is possible to continue to protect the devices other than the failed substrate. Therefore, the effect on the plant when the PLD based controller 6 fails is small.

FIG. 3 is a diagram showing a hardware configuration of the digital controller 1 shown in FIG. In FIG. 3, 1
Reference numeral 3 denotes a CPU board on which a CPU is mounted. 14a-14n
Is a DI board, and a digital controller input signal 49 necessary for the CPU board 13 to perform an operation is input to the DI boards 14a to 14n.

Reference numerals 15a to 15n denote DO substrates, each of which has a CPU
The digital controller output signal 50, which is the result of the operation performed on the board 13, is output from the DO boards 15a to 15n. Reference numeral 16 denotes a PIO bus.
Signal exchange between the I boards 14a to 14n and the DO boards 15a to 15n is performed through the PIO bus 16.

Further, in a recent plant, at least one digital controller 1 is always installed,
In an existing plant in which the digital controller 1 is already installed, or in a plant control device of a newly constructed plant in which the installation of the digital controller 1 is determined, the following may be performed.

That is, when logic to be processed by the digital controller 1 is added, the digital controller input signal 4 required to construct the logic to be added is required.
By adding DI boards 14a to 14n for inputting 9 and DO boards 15a to 15n for outputting digital controller output signals 50 from logic to be added, a small amount of hardware is added and a small space is taken. , It is possible to add logic to be processed by the digital controller 1.

Next, the differences between the plant control device shown in the first embodiment of the present invention and the prior art will be summarized and shown.
First, in the present embodiment, the device protection circuit 21 which is configured only by the hard wired logic 2 is abolished. In the present embodiment, the realization of the device protection circuit 21 in the hard wired logic 2 is abolished. The point that the controller 1 and the PLD-based controller 6 separate the device protection circuits 12 and 61 to calculate a device protection command and output the command via a duplex output circuit.

Due to this difference, the digital controller 1 has DI boards 14a to 14n and DO boards 15a to 15n.
By adding n, it is possible to add the logic of the device protection circuit to the digital controller 1 of the conventional control system by adding a small amount of hardware, and the PLD-based controller 6 can be implemented by a single board. It is possible to configure the device protection circuit 61 of about 1 to 5 devices.

According to the present embodiment, the hardware can be greatly reduced as compared with the case where the device protection circuit 61 is constituted by the hard wired logic 2, so that a more compact system than the conventional plant control system can be realized. It is possible, and furthermore, by employing the PLD-based controller 6, it is possible to realize a plant control device having high reliability and having little influence on the plant even in the event of a failure.

(Second Embodiment) (corresponding to [Claim 2]) FIG. 4 is a block diagram showing a second embodiment. FIG.
, The same functional portions as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. The difference between the present embodiment and the first embodiment will be described. In the present embodiment, as a method of duplicating the means for calculating the device protection command, the device protection command 46 of the digital controller and the PLD-based The point is that the logical sum with the device protection command 44 of the controller is used as the device protection command.

Therefore, even if one of the digital controller and the PLD-based controller, each of which duplicates the means for calculating the device protection command, cannot output the device protection command due to a failure or the like, the plant control device is not required. It is possible to continue to protect the equipment,
It is possible to prevent the malfunction of the device protection circuit due to a failure of the plant control device or the like.

According to the present embodiment, the continuity of the equipment protection function and the malfunction prevention function of the equipment protection function can be achieved more than the conventional plant control device, and the size can be reduced more than the conventional plant control system. It is possible to realize. Further, by employing the PLD-based controller 61, it is possible to realize a plant control device having high reliability and having little influence on the plant even in the event of a failure.

(Third Embodiment) (corresponding to [Claim 3]) FIG. 5 is a block diagram showing a third embodiment. FIG.
, The same functional portions as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. The difference between the present embodiment and the first embodiment is that the present embodiment employs a digital controller device protection command 42 and a PLD based controller device as a method of duplicating means for calculating a device protection command. The point is that the logical product of the protection commands 44 is used as the device protection command.

Therefore, even when one of the digital controller and the PLD-based controller, which duplicates the means for calculating the equipment protection command, malfunctions (outputs the equipment protection command) due to a failure or the like, the plant is not affected. As a control device, it is possible to continue protection of equipment, it is possible to increase the reliability of equipment protection function as a plant control device, and to prevent malfunction of equipment protection circuit due to failure of plant control device etc. It is possible to do.

According to the present embodiment, the reliability of the equipment protection function and the malfunction prevention function of the equipment protection function can be improved more than the conventional plant control device, and the size can be reduced more than the conventional plant control system. It is possible.
Further, by employing the PLD-based controller 6, it is possible to realize a plant control device having high reliability and having little influence on the plant even in the event of a failure.

(Fourth Embodiment) (corresponding to [Claim 4]) FIG. 6 is a block diagram showing a fourth embodiment. FIG.
, The same functional portions as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. The difference between the present embodiment and the first embodiment is that, in the present embodiment, a signal transmission path is formed between the digital controller 1 and the PLD-based controller 6 by the PIO bus 5, and the device control of the digital controller is performed. The command 41 and the device protection command 42 of the digital controller are transmitted from the digital controller 1 to the PLD-based controller 6 through the PIO bus 5.

As a result, a device operation command output circuit 66 for generating a device operation command 45 from the device control command 41 of the digital controller, the device protection command 42 of the digital controller, and the device protection command 44 of the PLD based controller is connected to the PLD based controller. It is an internal configuration. The device operation command output circuit 66 can be configured inside the device protection circuit PLD 62 in FIG.

Therefore, the PLD-based controller 6
Since the device operation command 45 output from the device becomes the operation command to the device as it is, and it is not necessary to configure the hard wired logic, the hard wired logic can be reduced. Further, the hardware output from the digital controller 1 becomes unnecessary, and the DO boards 15a to 15n become unnecessary, so that the number of DO boards of the digital controller 1 can be reduced.

According to the present embodiment, it is possible to realize a more compact system than the conventional plant control system. Further, by employing the PLD-based controller 6, the reliability is high. It is possible to realize a plant control device with less influence.

[0049]

As described above, according to the present invention, in a plant control device, means for protecting equipment disposed in a plant is provided by a digital controller and a PLD.
Since the configuration is duplicated with the base controller, there is an effect that it is possible to realize a more compact plant control system than the conventional plant control system, and to realize a plant control device with higher reliability and less influence on the plant even in the event of a failure.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment.

FIG. 2 is a hardware configuration diagram of a PLD-based controller.

FIG. 3 is a hardware configuration diagram of a digital controller.

FIG. 4 is a block diagram showing a second embodiment.

FIG. 5 is a block diagram showing a third embodiment.

FIG. 6 is a block diagram showing a fourth embodiment.

FIG. 7 is a system configuration diagram of a conventional plant control device.

FIG. 8 is a detailed diagram of logic configured inside a conventional plant control device.

[Explanation of symbols]

 Reference Signs List 1 digital controller 11 control circuit 12 equipment protection circuit 13 CPU board 14a to 14n DI board 15a to 15n DO board 5 PIO bus 6 PLD based controller 62 PLD for equipment protection circuit 63 PLD for variable timer circuit 64 input circuit 65 output circuit 66 equipment Operation command output circuit 2 Hard wired logic 20 Duplex output circuit 3 Plant 31 Motor-operated valve 32 Fan 33 Pump

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Nobuyuki Takahashi 1 Toshiba-cho, Fuchu-shi, Tokyo F-term in Fuchu Works, Toshiba Corporation (reference) 5H209 AA01 GG01 HH15 SS01 SS05 SS08 TT04

Claims (4)

[Claims] A plant control device for controlling the operation of various devices disposed in a plant, wherein a device control command for operating the various devices and an abnormality of the various devices or an abnormality of the plant are determined. A digital controller having a CPU for calculating two commands, that is, a device protection command for performing an operation of protecting the various devices when receiving a signal indicating the above, and a PLD for calculating only the device protection command. A plant control device comprising a PLD-based controller, wherein means for calculating the device protection command is duplicated by the digital controller and the PLD-based controller. 2. The plant control apparatus according to claim 1, wherein a logical sum of a device protection command from said digital controller and a device protection command from said PLD-based controller is used as a device protection command for said various devices. A plant control device characterized by the above-mentioned. 3. The plant control device according to claim 1, wherein a logical product of a device protection command from said digital controller and a device protection command from said PLD-based controller is used as a device protection command for said various devices. A plant control device characterized by the above-mentioned. 4. The plant control device according to claim 1, wherein the CPU calculates the device control command and the device protection command.
A PLD-based controller including a PLD that calculates only the device protection command, and a transmission system that forms a transmission path for signals between the digital controller and the PLD-based controller. By transmitting the device control command and the device protection command calculated by the digital controller to the PLD-based controller through the transmission system, the device control command and the device protection command calculated by the digital controller, and further, the device protection command calculated by the PLD-based controller A plant control device, wherein a device operation command output circuit for creating a device operation command from a command is configured inside a PLD-based controller.