JPS61112203A - Process computer system for supervisory of plant - Google Patents

Abstract

PURPOSE:To attain extraction of ON/OFF signals without adding a control board relay nor other remodeling by detecting the change of the current flowing through a circuit to extract the ON/OFF signals out of the control board. CONSTITUTION:A clamp type current detector 3 is attached to a cable 14 connecting a contact bar 11A of a switch lever 11 of a control board 1 and a relay 12. The output of the detector 3 is supplied to a process input device 24 of a supervisory unit 2 and fetched by a computer 21. This avoids the increase of the power supply capacity of the board 1 due to addition of relays, the inconvenience caused by a change of a circuit for adding jobs, etc. Thus the ON/OFF signals can be easily added.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a plant and a process computer system for plant monitoring that monitors the plant status by inputting necessary information from a control panel for controlling the operation of the plant.

[Technical Background of the Invention] Most of the operations of complex and large-scale plants such as power generation plants are automatically performed using computers. In this case, the work of i-transposition is done by monitoring the plant status via a control panel, display means such as a color CRT, and notification means.

Check the progress of the control at each point in the control sequence, input the primary control command into the process computer, or detect an abnormality in the plant state quantity to restore it to normal. Main duties include operating control panels and manually operating current equipment. Therefore, in order to operate a plant safely, it is more important than anything else to always have an accurate grasp of the plant status.To do this, various information from the plant and control panel is input into a process computer, processed, and colored. The information desired by the operator can be immediately displayed on various CRT screens.

[Problems with Background Art] In such a process computer system for plant monitoring, in order to further improve the plant monitoring performance, there are cases where it is desired to newly input various relay outputs provided in the control panel to the computer side. Such requests often occur especially when a computer is replaced with a higher performance one. In that case, conventionally the circuit inside the control panel was modified and a new relay was added.

Since this information was input into a computer, it required a lot of work to modify the control panel, and if there was no room for modification,
There was a problem in that the on/off signal could not be imported into the computer, making it impossible to improve monitoring performance.

[Object of the invention] An object of the present invention is to provide a process computer system for plant monitoring that can take out on-off signals without adding a new relay when taking out on-off signals from a control panel and inputting them to a computer. shall be.

[Summary of the Invention] Therefore, the present invention attaches a clamp-type current measuring device to the electric wire carrying the signal to be extracted in the control panel, and converts the output signal into an on/off signal that can be input to a computer via a voltage change converter. By inputting the information into a computer, the necessary on/off signals can be extracted without adding a relay in the control panel.

[Embodiments of the invention] The present invention will be explained in detail below.

FIG. 1 shows a process computer system for plant monitoring according to an embodiment of the present invention, from a control panel 1 to a monitoring device!
! 2 shows a configuration diagram for additionally inputting a new on/off signal to No. 2. The control panel 1 is equipped with instruments and display lamps that display various plant status quantities, as well as operating devices, etc. Among them, Figure 1 shows a switch operation lever 11 provided on the panel surface and its switch operation. A switch circuit 13 having a relay 12 that is turned on and off in response to one operation of the lever 11 is shown. On the other hand, the monitoring device 2.

31 calculation 21 and the color CRT 22 connected to it,
It is composed of a typewriter 23 and a process input device 24, and a large number of 48
To enter the number 1. A number of signal cables are connected to the process input bag @24, but these are all not shown.

In this embodiment, a new signal is additionally inputted to the monitoring device 2 from the switch circuit 13 of the control panel 1.

A clamp type current detector 3 is attached to the cable 14 that connects the relay 12 and the contact piece 11A of the switch operation lever 11, and its output is sent to the computer 21 via the voltage change detector 4.
is input to the computer 21 from the process input device 24.

FIG. 2 shows the mounting of the clamp type current detector 3 in the state a.
This can be easily attached without removing or cutting the cable 14 by simply clipping it onto the cable 14 wired to the switch box IIB that houses the contact piece 11A. Further, this clamp type current detector 3 can be easily constructed using a Hall element (InAs) having a characteristic of outputting a voltage in proportion to the strength of a magnetic field.

FIG. 3 shows a configuration diagram of the voltage change detector 4. The voltage change detector 4 includes a voltage adjustment section 41 that adjusts the level of the voltage input from the clamp type current detector 3 via the cable 5. , a threshold determination section 43 that compares and determines the voltage threshold set in the threshold setting section 42 and the input voltage, a contact output section 44 that outputs a contact signal according to the output to the cable 6, and a voltage change detector 4. It consists of a power supply monitoring output section 45 that outputs a power state signal 80 to the monitoring device 2 in response to whether the power supply 70 is turned on or off, and outputs a power abnormality signal 90 to the contact output section 44 when the power supply 70 is turned off.

FIG. 4 shows a specific example of the voltage change detector 4 shown in FIG. 3. The power supply adjustment section 41 can be composed of an operational amplifier, and a cable 5 is connected to each input terminal of the operational amplifier. Ru. The threshold value setting section 42 can be configured with a variable resistor.6 Moreover, the threshold value determination section 43 can also be configured using an operational amplifier, and the output terminal of the voltage adjustment section 41 is connected to the inverting input terminal thereof, and the output terminal of the voltage adjusting section 41 is connected to the non-inverting input terminal thereof. is connected to the slider end of the variable resistor constituting the threshold value setting section 42. Furthermore, the contact output section 4
4 can be configured using an oven collector, and by connecting a plurality of open collectors in parallel, a plurality of on/off signals can be outputted to a plurality of cables 6 as in the case of a relay contact.

With the above configuration, when the switch operation lever 11 provided on the panel of the control panel 1 is operated to turn the contact piece 11A on and off as shown in FIG. 125v is applied. Accordingly, a current of 10 (bnA) flows through the relay 12 and into the cable 14 from the state of O+sA, as shown in FIG. 2(b).

This is detected by the clamp type current detector 3 and inputted to the voltage change detector 4.

In the voltage change detector 4, the voltage detected by the clamp-type current detector 3 is amplified by the voltage adjustment section 41, and the voltage detected by the clamp-type current detector 3 is amplified.
As shown in FIG.
By comparing it with the threshold voltage Vs obtained from , a signal is obtained that turns the contact output section 44 from the off state to the on state, as shown in FIG.

As a result, in the process input bag @24 of the monitoring device 2,
In exactly the same way as in the case of a relay contact, a change in the state of the contact output section 44 from the OFF state to the ON state can be detected, and this can be converted into a contact signal of the relay 12 and input to the device 2I.

As described above, it is possible to input the desired on/off signal to the computer 21 of the monitoring device 2 without making any circuit changes such as adding a new relay to the current circuit in the control panel. .

By the way, in the case of current detection using the clamp type current detector 3, the influence of current from other circuits in the control panel is considered, but by shielding the detector and cable, the shadow W from the outside can be eliminated. Can be done. At the same time, on/off detection is not a measurement of the current value, but a judgment of whether it is flowing or not. Therefore, the on/off state of the relay 12 can be detected without the need for the detector to have particularly high precision.

On the other hand, since the on/off detection is performed by detecting current changes, there is no mechanical movement such as application to relays, operation of electromagnets, or opening/closing of contact relays as in conventional methods, and the response speed also depends on the current. Change detection is on the order of nanoseconds, and extremely good on/off detection is possible.

Also, depending on the specifications of the relay, the current flowing through one circuit may be several tens of mA, but in this method, rather than using the current value, it uses whether or not the current is flowing. This can be easily handled by changing the degree of voltage increase in step 4.

Also, the power supply 7 driving the voltage change detector 4
If an abnormality occurs in 0, it is conceivable that the output from the contact output section 44 will be turned off unconditionally. For example, in the case of the 832 function, even though the switch is not operating because the voltage change detector 4 is powered off, it will output an output as if it were operating, which would cause errors in plant monitoring. It may lead to judgment. However, in one embodiment.

When the power supply monitoring output unit 45 outputs the power supply state output 80 to the OFF state of the voltage change detector 4, the computer 21 inputs this and determines that. By treating this as an input abnormality, it is possible to avoid erroneous judgments due to power-off of the voltage change detector 4.

In addition, when a power supply abnormality occurs, the power supply monitoring output section 45
The power abnormality output 90 is sent to the contact output section 44, and the contact output section 44 behaves in the same way as a power abnormality in a normal contact output relay, that is, when the contact output type is A-type, it outputs an OFF output due to a power abnormality. In the case of B controller, the output is turned on.

As a result, the total unit 21 can handle the input from the voltage change detector 4 in the same way as a normal contact output, and can also monitor whether the contact input is normal or abnormal by monitoring the power status output 80. This means that the highly reliable on/off switch (No. 3) can be taken out from the control panel 1.

In the above embodiment, the circuit voltage is DC, but the same can be applied to an AC circuit.

Further, in this embodiment, the operation of the A-conductor which is turned on when a current flows is explained as an example, but the operation of the B-conductor, that is, the operation which is normally on and is turned off when a current flows, is also the operation of the contact output section 44. This can be easily achieved by reversing the .

[Effects of the invention] As mentioned above, since the on/off signals are extracted from the control panel by detecting changes in the current flowing through the circuit, modifications such as adding a control panel relay to extract the on/off signals may be necessary. It is possible to extract on/off signals without having to do so. This eliminates problems such as an increase in the power supply capacity of the control panel due to the addition of relays and problems caused by circuit changes during additional work, and it becomes possible to easily add on/off signals.

This can be easily done in a plant that is already in operation, rather than in a newly created plant, when a large amount of input from the control panel is added and imported into the computer system 11 in order to improve the monitoring function. As a result, the monitoring performance and operability of the existing system will be improved, and the safety of the entire plant will be ensured.

[Brief explanation of drawings]

Fig. 1 is a configuration diagram showing an embodiment of the present invention when a new on/off signal is input from a control panel to a computer, Fig. 2 is an explanatory diagram of the mounting state of the clamp type current detector shown in Fig. 1, and Fig. 3 The figure is a block diagram of the voltage change detector in Figure 1, Figure 4 is a circuit diagram showing a specific example of Figure 3, and Figures 5 (a) to (d).
) is a time chart I for explaining the operation of the embodiment shown in FIGS. 1 to 4. l... Control panel, 2... Monitoring device, 3... Clamp type current detector, 4... Voltage change detector, 5, 6.1
4... Cable, 11... Switch operation lever, 1
2... Relay, 13... Switch circuit, 21 ・
...Calculator, 22...Color CRT, 23...Typewriter, 24...Process input device, 41...
Voltage adjustment section, 42...Threshold value setting section, 43...Threshold value determination section, 44...Contact output section. 45...Power monitoring output section 6
'□Agent Patent attorney Mon Makoto Hijiri Figure 2 Figure 3 Door 0 Figure 4 Figure 5

Claims (1)

[Claims] In a process computer system for plant monitoring, which enables plant status monitoring by inputting necessary information from the plant and control panel into a computer, processing it, and displaying it, the current magnetic field created by the current flowing through the wires is By using a clamp-type current detector that detects and outputs a voltage proportional to the flowing current, and a voltage change converter that captures changes in the voltage output from this clamp-type current detector and creates an on/off state. A process computer system for plant monitoring, characterized in that it is possible to newly input on/off signals from a control panel to the computer without modifying the circuit wiring of the existing control panel.