JPS60134303A - Fault detecting device - Google Patents

Abstract

PURPOSE:To raise a reliability by providing a fault detecting device and a preliminary control system having switching command device, and providing fault detecting circuits of sudden change, slowness and oscillation on this fault detecting device. CONSTITUTION:A control operating device 2 exceutes a control operation of PID, etc. by using a process signal 1 as an input signal, and outputs a control signal 3. A fault detecting device 10 for detecting instantaneously a fault of this device 2 executes the same control operation as that of the device concerned 2 by a control operation imitating part 11, and calculates a deviation of a mimic control signal 11' of its result and the control signal by a deviation operating part 12. This deviation signal 12' is supplied to each fault detecting part of sudden change 13, slowness 14 and oscillation 15, and a fault corresponding to a fault mode of a control device is detected. This fault detection is transferred to an operator by an indicator 20, switched to a backup control signal 6 by other control device by a control operating part switching device 4 is accordance with a control signal switching signal 7, and the control is containued.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a failure detection device, and particularly to a failure detection device applicable to a PWR plant reactor control system, etc.

In general, a process control system is comprised of a detector θ, a control arithmetic unit O2, and an operating end 03, as shown in FIG. 1, for example. In such conventional process control systems,
For example, if the control arithmetic unit O2 breaks down and is left as is, there is a drawback that the operation of the gross processor O4 may become impossible.

The present invention has been proposed in view of the above-mentioned circumstances, and its purpose is to be able to detect failures of control calculation devices at an early stage, and to detect failures in order to maintain operation when failures occur. The purpose of the present invention is to provide a complete set of failure detection devices capable of detecting failure details.

The failure detection device according to the present invention includes a main control system having a control calculation device and a switching device, a backup control system having a failure detection device and a switching command device, and a failure detection device having a simulation calculation device and a deviation calculation device to detect sudden change failures. The present invention is characterized by being equipped with a circuit, a slow failure detection circuit, and an oscillation failure detection circuit, and is capable of instantly detecting any failure of the control arithmetic unit and identifying the details of the failure, thereby solving the above-mentioned drawbacks of the conventional system. This is how it was done.

An embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 is a block diagram showing the configuration of an embodiment of the present invention, FIG. 3 is a diagram for explaining failure detection in the case of a sudden change fault and a slow fault in the embodiment shown in FIG. 2, and FIG. A diagram showing the waveforms of the control device output signal and the simulated control calculation value.
FIG. 3 is a diagram for explaining failure detection at the time of an oscillation failure in one embodiment shown in the figure.

In general, the failure modes of control calculation devices such as function generators and PID controllers include sudden change failures in which the output suddenly swings to the high or low side, outputs gradually drifting, or corporate power failures regardless of the input value. is designed to instantly detect failures in these control/arithmetic devices.

In FIG. 2, 1 is a process signal, 2 is a control calculation device,
3 is a control signal, 4 is a control calculation unit switch, 5 is a control signal,
6 is a backup control signal, 7 is a control signal switching signal, 1
0 is a failure detection device, 1 is a control calculation simulation section, and 12 is a deviation calculation section (or a switching signal generator).

Using signal 1 as an input signal, control calculations such as PID are performed and control signal 3 is output.

It is economically advantageous to configure the failure detection device 1O, which is intended to instantly detect failures in the control calculation device 2, by a computer when there are many control devices to be handled, but it is also possible to configure it by computer-based logic. I don't mind. This failure detection device 1
O takes in the same input signal as the control calculation device 2, and executes exactly the same control calculation in the control calculation simulation unit 1.
The difference is calculated by the deviation calculating section 12, and all failures according to the failure mode of this deviation signal device are detected.

As one example of application of the present invention, if a failure is detected in each of the failure detection units 13, 14, and 15, the occurrence of the failure is communicated to the operator on the display 2O. In addition, in order to ensure that automatic operation can be continued in the event of a failure, the control signal switching signal 7 is switched to the backup control signal 6 from another control device using the control calculation unit switch 4 as soon as the failure is detected to continue control. .

In the example shown in FIG. 2, the backup control signal 6 is generated by the control calculation simulation unit 11 of the failure detection device 100, but a backup signal from another device may also be used.

The operation of the above embodiment of the present invention will be explained.

To detect failures corresponding to failure modes of control equipment,
The failure detection device 10 uses the same human power as the control calculation device 2,
When the same control calculation is performed and the deviation between the calculation result in the failure detection device 10 and the control calculation device 2 exceeds a preset value, the control wave>4. Device 2 is assumed to be out of order.

Further, depending on the failure mode, the deviation may occur suddenly and large (sudden failure) or slowly and small (slow failure).

In this case, failure detection is as shown in FIG. 3, when the deviation ε continues to be at the preset value χ for 1 second, the control arithmetic unit 12 is found to have failed. In the case of a sudden change failure in the above-mentioned failure generation situation, the set value χ may be set sufficiently large, and the duration time may be set sufficiently small in consideration of misdiagnosis due to process noise.

In addition, in the case of a slow failure, it is possible to detect a sudden change failure by decreasing the set value χ and increasing the duration.

Furthermore, in the case of a failure that causes a cyclic oscillation phenomenon, the oscillation output signal of the control device is normally transmitted to the process via the operating end, as shown in Figure 4, and follows the closed-Luno characteristic that includes the failed control device. This induces fluctuations in the process, and the simulated control signal calculation value has a similar waveform with a delay with respect to the control output signal. Therefore, as shown in Fig. 5, the deviation between the control calculation unit 2 and the simulated control calculation value is determined by a preset period of time in order to distinguish it from conditions other than oscillation failures (for example, temporary noise or slow fluctuations in the process). Preset detection is possible within 1 second.

As described above, according to the present invention, a failure in a control device can be detected instantaneously and the failure mode can be identified at the same time, so in combination with a pack-up device, automatic control can be continued, thereby increasing the reliability of a multi-control system. This provides excellent effects such as improved performance.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a conventional example, FIG. 2 is a block diagram showing the configuration of an embodiment of the present invention, and FIG. 3 is a block diagram showing the configuration of the embodiment shown in FIG. FIG. 4 is a diagram showing the waveforms of the control device output signal and the simulated control calculation value, and FIG. 5 is a diagram for explaining failure detection in the case of an oscillation failure in the embodiment shown in FIG. 2. This is a useless diagram. 1... Process signal, 2... Control calculation device, 3...
- Control signal, 4... Control calculation unit switch, 5... Control signal, 6... Back eye control signal, 7... Control signal switching signal, 10... Failure detection device, 11...・Control calculation simulation unit, 12...Deviation calculation unit, 13...Sudden failure Applicant sub-agent Patent attorney Takehiko Suzue Continued from page 1 [Phase] Inventor 1) Shoji Kuchi Hyogo, Kobe City 1-1-1 Wadazaki-cho Shrine Kobe Shipyard & Machinery Works Mitsubishi Heavy Industries, Ltd.

Claims (1)

[Claims] A preliminary control system having a failure detection device and a switching command device is provided in the main control system having a control calculation device and a switching device, and a sudden change failure detection circuit is provided in the failure detection device having a simulation calculation device and a deviation calculation device.
A failure detection device comprising a slow failure detection circuit and an oscillation failure detection circuit.