JP2000266883A - Input signal diagnosis system and instrumentation equipment using it in nuclear power plant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect an abnormality at an early stage and lessen the work during a periodic inspection by always collecting and analyzing signals during operation to detect an abnormality or a sign of it in input signals. SOLUTION: A device 40 for collecting and processing data collects signals from a multiplexed signal detection means, conducts the statistical processing of the data in an interval between the beginning and the end of each regular period and detects an abnormality of an input signal for the signal detection means on the basis of the results of the statistical processing of the data. Then, the device 40 always collects and analyzes signals during operation to detect an abnormality or a sign of it in input signals. In other words, the output of the signal detection means consisting of transmitters 11 to 14 and signal processing components 21 to 24 is collected by the device 40 for collecting and processing data by way of a transmission route 30. Bistable signals from the signal processing components 21 to 24 are inputted into a reactor shutdown equipment 50 to drive a trip breaker. The device 40 for collecting and processing data always collects and analyzes data in the signal processing components 21 to 24 during the operation of a reactor to find an abnormality. Computers are usually used as the device 40.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an input signal diagnostic system for detecting an abnormality in an input signal used in a triple or quadruple system such as a protection system for a nuclear power plant.

[0002]

2. Description of the Related Art A nuclear power plant requires process instrumentation for measuring a process amount in a primary cooling system and other auxiliary systems. The process instrumentation includes a detector and an instrument rack for storing various instruments. The output from the instrument rack is sent to a reactor shutdown facility that automatically shuts down the reactor in the event of an abnormality, or to an engineering safety facility operating facility that starts up the necessary equipment in the event of an accident.

[0003] Among them, parameters necessary for the reactor protection equipment and the engineering safety equipment operating equipment are treated as process instrumentation of the safety protection system. The process instrumentation of this security system is designed to have a multiplicity, and the multiplexed channels are separated from each other including the detector. The instrument rack is divided into four or three channels for independence.

In recent years, with the digitization of instrumentation systems,
Various operations in such a protection system are digitally operated. The arithmetic unit can detect abnormalities at a considerably high rate by software invariance and self-diagnosis.

However, the detector (or the transmitter having the function of the detector) and its converter still include many mechanical parts and analog circuits.
At the time of periodic inspection, etc., it is necessary to perform an inspection by adding a simulation signal.

FIG. 2 is a configuration diagram of a part of a protection system for detecting an abnormal signal. Signals such as the pressure and temperature of the reactor detected by the detection element are sent to the signal conditioner 2 by the transmitter 1. The signal conditioner is
It is a signal converter that performs an operation on the signal from the transmitter 1 and converts the signal into a signal that can be easily handled by the subsequent A / D converter 3.

The output of the signal conditioner 2 is converted into a digital signal by an analog / digital converter (hereinafter, referred to as an A / D converter) 3 and then input to a digital operation unit 4 where a predetermined operation is performed. In some cases, the signal conditioner 2 and the A / D converter 3 are integrated.

[0008]

By the way, the transmitter 1, the signal conditioner 2 and the like have many mechanical parts and analog circuits, and it is difficult to perform a self-diagnosis by nature. The portion of the A / D converter 3 other than the reference voltage is automatically calibrated by means of automatic calibration or the like. There is a problem that the signal is checked in addition to the transmitter, the inspection work is extremely complicated, and a large number of man-hours are required.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, and not to perform intermittent checks such as periodic inspections, but to constantly analyze data during operation to detect abnormalities at an early stage and reduce periodic inspection work. An object of the present invention is to realize an input signal diagnosis system for a safety protection system and an instrumentation facility of a nuclear power plant using the same.

[0010]

In order to achieve the above object, according to the first aspect of the present invention, there is provided a system for detecting an abnormality of a signal from a multiplexed detecting means,
A data collection process for collecting signals from the multiplexed signal detection means, performing statistical processing on data in the section at regular time intervals, and detecting an abnormality in an input signal of the signal detection means based on the statistical processing result The apparatus is characterized in that the apparatus includes a device, and is configured to constantly collect and analyze signals during operation to detect an abnormality of the input signal or a sign of the abnormality.

According to such a configuration, the state of the input signal can be always grasped during operation, so that early detection of abnormality is guaranteed. Further, in the instrumentation facility of the nuclear power plant, the inspection points can be narrowed down before the periodic inspection, and the period of the periodic inspection and the number of man-hours can be reduced.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. FIG. 1 is a configuration diagram showing an embodiment of the input signal diagnostic system according to the present invention.

First, a general reactor protection facility will be described. Reactor protection equipment is equipment for detecting an abnormal state of a reactor by means of process instrumentation of a safety protection system, tripping the reactor, and protecting the reactor. This protection device receives a bistable signal (operation signal of the alarm setter) from the process instrumentation and generates a reactor trip signal and an interlock signal, and automatically opens according to the reactor trip signal. It consists of a reactor trip breaker. Reactor shutdown facilities are:
It is multiplexed for security and consists of two trains or four trains.

In FIG. 1, reference numeral 11 denotes a transmitter 1 shown in FIG.
Is a signal processing unit from the signal conditioner 2 to the digital operation unit 4 shown in FIG. Note that the portion including the transmitter 11 and the signal processing unit 21 is referred to as signal detection means here. The signal detecting means has the same configuration and is provided for four channels, and the output is collected by the data collection processing device 40 via the signal transmission line 30.

The bistable signals from the signal processing units 21, 22, 23, and 24 are input to the reactor stop equipment 50 having two or four trains, and the output of the reactor stop equipment 50 causes a reactor trip breaker (not shown). Is driven.

The data collection processing device 40 has a function of constantly collecting and analyzing data of the signal processing units 21, 22, 23 and 24 during the operation of the nuclear reactor, and finding an abnormality. As the device 40, a computer including an input / output device, a display device, a storage device, and the like is generally used.

The abnormality detection function by the statistical processing in the data collection processing device 40 includes, for example, the following. Statistical processing is performed on the digital output signal from the signal processing section by dividing the digital signal at regular intervals, and a section average value for each section, a standard deviation representing signal variation, a maximum value, a minimum value, and other statistical indexes are obtained. An abnormality of the input signal is detected based on the value.

The section average value of the multiplexed signals,
Calculate the deviation of statistical indicators such as standard deviation, maximum value, minimum value, etc.,
This is recorded as a trend, and the trend is monitored to detect an abnormality. An alarm is issued when an abnormality occurs in the deviation trend.

Before the periodic inspection, the above data is closely examined to narrow down inspection points. As a result, the period of the periodic inspection and the number of man-hours can be reduced.

These functions are performed by the data collection processing device 40
Can be selected and executed by using an input / output device (not shown) provided in the computer.

In such a configuration, the data collection processing device 40 performs each of the above-mentioned processes. Through such processing, abnormality of the reactor can be checked in real time, and an alarm can be issued when an abnormality occurs.

Further, at the time of a periodic inspection, it is possible to extract only those parts that really need to be inspected by closely examining the past data, and to specify the target of the inspection work. Therefore, the inspection period and man-hours can be reduced.

It should be noted that the foregoing description has been directed to specific preferred embodiments for the purpose of describing and illustrating the invention. Therefore, the present invention is not limited to the above-described embodiments, and includes many more modifications without departing from the spirit thereof.
This includes deformation.

In the embodiment, the case where the input signal diagnostic system of the present invention is used for a protection system of a nuclear power plant has been described as an example. However, the input signal diagnostic system of the present invention is not necessarily limited to this. Instead, it can be widely used in other multiplexed abnormality monitoring systems and the like.

[0025]

As described above, according to the present invention, the following effects can be obtained. It is possible to constantly monitor the input signal line, that is, the transmitter output signal. At the time of the periodic inspection, it is sufficient to inspect the data in which signs of abnormality are found by closely examining the data, and to inspect only one of the channels in general inspection. Regular inspection alone will find any anomalies at that point in time, but will not find anything at that point. In the system of the present invention, the abnormality is constantly monitored during the operation period, so that a sign of a failure can be found early.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing one embodiment of an input signal diagnostic system according to the present invention.

FIG. 2 is a configuration diagram of a part of a protection system for detecting an abnormal signal.

[Explanation of symbols]

 1, 11, 12, 13, 14 Transmitter 2 Signal conditioner 3 A / D converter 4 Digital operation unit 21, 22, 23, 24 Signal processing unit 30 Transmission line 40 Data collection processing device 50 Reactor shutdown facility

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Claims (7)

[Claims] 1. A system for detecting an abnormality of a signal from a multiplexed detection means, comprising: collecting a signal from the multiplexed signal detection means; and statistically processing data of the section at regular time intervals. A data collection processing device that detects an abnormality of the input signal of the signal detection means based on the statistical processing result, and constantly collects and analyzes the operating signal to detect an abnormality of the input signal or a sign of the abnormality. An input signal diagnostic system characterized by being configured as described above. 2. The data collection processing device according to claim 1, wherein the signal from the signal detection means is divided at regular time intervals, and a statistical index such as a section average value, a standard deviation, a maximum value, a minimum value, etc. is obtained for each section. The input signal diagnostic system according to claim 1, further comprising: 3. The data collection processing device has a function of calculating deviations of statistical indices such as a section average value, a standard deviation, a maximum value, and a minimum value between signals from the multiplexed signal detection means. The input signal diagnostic system according to claim 1, wherein: 4. The input signal diagnostic system according to claim 3, wherein the data collection processing device has a function of recording the trend of the deviation and detecting an abnormality from the trend. 5. The input signal diagnostic system according to claim 4, wherein said data collection processing device has a function of issuing an alarm when an abnormality occurs in said deviation trend. 6. An instrumentation facility for a nuclear power plant using the input signal diagnostic system according to claim 1. 7. Using the input signal diagnostic system according to claim 1 to 5, inspect the collected data before the periodic inspection and narrow down the inspection points so as to focus on those having signs of abnormality. Instrumentation equipment for a nuclear power plant, characterized in that it is configured to perform