JPH02205798A - Operation analyzer of control rod drive device - Google Patents

Abstract

PURPOSE:To precisely perform a characteristic analysis of a coil current and operation sounds at high speed by providing the analyzer with a detector for detecting an operator, a buffer amplifier, pretreatment equipment and an arithmetic unit for analyzing and processing operating items of a current signal and a detection signal. CONSTITUTION:The currents of coils 6-8 is allowed to a control board 5 of a control rod drive device CRDM and are taken out as respective equivalent voltage signals from monitor signal terminals 9a-9c of its power cabinet 9. Operation sounds of the CRDM are taken out from an accelerometer 11 attached to a CRDM housing 10. After the control signals of the CRDM is taken out from a test point terminal 13a of a logic cabinet 13 of the CRDM control board 5 and each signal is insulated through a buffer amplifier 14, they are input in a CRDM operation monitor system S. After the system S is provided with pretreatment equipment 15, an arithmetic device 16 and the like and a voltage signal for showing a coil voltage, a detection signal for showing CRDM operation sounds and a CRDM control signal are digitalized by the device 15, their characteristics are analysed by the device 16 and these results are output on a CRT display 17 and the like.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an operation analysis device for an electromagnetically driven control rod drive bag f (CRDM) applied to a pressurized water reactor (PIIR), etc. .

[Prior Art] In order to drive the control rods (withdrawal and/or insertion of the control rods into the reactor core), a three-coil type electromagnetic coil consisting of an electromagnetic coil for lifting, an electromagnetic coil for a fixed gripper, and an electromagnetic coil for a movable gripper is used. It is well known that a drive device is used, and one example of its typical structure is the Japanese Utility Model Publication No. 57-359.
It is disclosed in Japanese Patent No. 12 as a "linear motion device".

FIG. 5 shows the main parts of the linear motion device, that is, the control rod drive device disclosed in the publication.The drive device grips the groove of the drive shaft 1 connected to the upper part of the control rod, The control rod is withdrawn/inserted, and such control rod operation is performed in 1
This is realized by the vertical movement of a movable magnetic pole 2 called a lunger and the gripping and release of a cavity 3 by a link mechanism.

Here, the above-mentioned vertical movement of the arranger 2 is obtained by energizing the electromagnetic coil 6.7.8 provided on the outer periphery to generate magnetic force. The flowing current includes a back electromotive current component corresponding to the operation of plunger 2, so by analyzing the characteristics of the coil current and the operation sound when plunger 2 operates, it is possible to indirectly The operating status of the plunger 2 can be known.

Conventionally, when analyzing the operating status of one langier using the above-mentioned principle, the coil current waveform and operating sound waveform were analyzed at once because the operating time of the control rod drive device is extremely fast at 780 m5ec per step. They put it into an oscillograph, had it write on it, and then manually analyzed the characteristics of the coil current and operating sound.

[Problems to be Solved by the Invention] However, the number of steps per stroke of the control rod drive device, that is, one extraction/insertion is 228X 2 = 4
For example, if there are 53 control rod drives in a pressurized wooden nuclear reactor plant with a four-loop secondary cooling system, in order to analyze all steps for all control rod drives, is 456x53=24168
Multiple data analyzes will be required.

Manual analysis requires approximately 20 minutes per step, so not only does analysis of the above-mentioned amount of data require an enormous amount of time or a large number of personnel, but the analysis must also rely on human labor. Therefore, human errors cannot be avoided, which can lead to errors in judgment when conducting systematic evaluations.

Therefore, in view of the fact that the control rod drive device is an important device involved in the control of nuclear power plants, it is an object of the present invention to automatically analyze the characteristics of the coil current and operating noise of the control rod drive device at high speed and accurately. An object of the present invention is to provide an operation analysis device for a control rod drive device, which enables quick and appropriate response in the event of an abnormality in its operation.

[Means for Solving the Problem] In order to achieve this object, the present invention includes an electromagnetic coil for lifting and lowering that is operated by a control signal from a control device, an electromagnetic coil for a fixed gripper, and an electromagnetic coil for a movable gripper. An operation analysis device for an electromagnetically driven control rod drive device, comprising: a detector connected to the control rod drive device to detect its operation sound; two electromagnetic coils for lifting, the electromagnetic coil for the fixed gripper, and the movable gripper. receiving a current signal from each of the electromagnetic coils, a detection signal from the detector, and the control signal from the control device [an impulse amplifier;
A preprocessing device that digitizes each of the current signal, the detection signal, and the control signal; and an arithmetic processing device that analyzes operating specifications of the current signal and the detection signal. It is.

[Function] The current signal of each electromagnetic coil, the detection signal of the detector,
The control signal from the control device is sent to the Ili amplifier and isolated, and then preprocessed and converted into a digital value by a preprocessing device consisting of a channel converter and an analog/digital converter.

In order to accurately analyze the characteristics of coil current and operating noise,
The signal acquisition period can be set to an appropriate sampling time (for example, 0.5 to 1.0 m5ec).

The signals converted as described above are input to an arithmetic processing unit, where the operating specifications or operating information of each coil current and operating sound signal, i.e., whether the coil current is turned on or not is determined for the plunger of each coil. The time from when the coil current is turned off until the plunger completes its opening operation, the slope of the rise of the current, and the current waveform generated by the plunger operation. The magnitude of distortion, etc. is calculated for each step according to a predetermined analysis processing program.

The calculation results are displayed on the CR7 screen and/or printer in various forms.
It can be displayed on a plotter.

[Embodiments] Next, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Fig. 1 shows a conceptual diagram when the operation analysis device of the present invention is applied to a pressurized water type nuclear power plant to perform online operation monitoring. CRI) M can be as disclosed in the above-mentioned Japanese Utility Model Publication No. 57-35912, and includes a lifting electromagnetic coil (lift coil) 6 housed in the housing 10 and a movable gripper electromagnetic coil ( NG coil) 7 and a fixed gripper electromagnetic coil (SG coil) 8. To briefly explain the operation, during normal operation before the control rod drive device CR [IN is operated, the drive shaft 1 (see FIG. 5) is held by the SC coil 8. For example, when the drive shaft 1 is raised, the NG coil 7 is excited by a control signal to be described later, and when it is sufficiently excited, the SC coil 8 is demagnetized, and then the lift coil 6 is excited, and the drive shaft 1 is Step up. Then, the SC coil 8 is excited, and when it is sufficiently excited, the NG coil 7 and the lift coil 6 are demagnetized, and one step is completed.

The currents in these coils 6-8, operating as described above, are:
The signals are sent to the control panel (control device) 5 of the CRDM, and are sent to the monitor signal terminals 9a, 9b, 9c of the power cabinet 9.
The operating sound of the control rod drive device CRDM is extracted as an equivalent voltage signal from the CRf1M housing 1.
The control signal for the control rod driving bag g CRDM is output as a detection signal by the accelerometer (operation sound detector) 11 attached to the control rod drive bag g via the so-called charge amplifier 12.
These signals are taken out from the test point terminal 13m of the
HDM operation monitoring system is installed.

The operation monitoring system S includes a preprocessing device 15 consisting of a channel converter and an analog/digital converter (not shown).
, an arithmetic processing device 18 which may be a computer connected to the preprocessing device 15, and a CR connected to this arithmetic processing device 16.
1) and a printer/plotter 18. The voltage signal representing the coil current, the detection signal representing the CRDM operating sound, and the CRDM control signal are sent to the preprocessing device 1.
After being digitized in step 5, it is transferred to an arithmetic processing unit 16, where characteristic analysis is performed according to an analysis processing program, and the results are output to a CR7 display device 17 and/or a printer/plotter 18. Reference numeral 19 indicates a data recording device, and the operation monitoring system S
The input signals to can also be transferred here in parallel and recorded and archived.

Next, the outline of the analysis processing program will be explained with reference to Section 2 and FIG. 3. In FIG. are respectively coded 20.21.22
．． 23 and 24, and in the analysis processing program, from these input signals 20 to Z2, the time point a when the coil current is applied and the time point when it is turned off are determined for each coil. Also, plunger 2 (see Figure 5)
The time point C at which the 7 langier 2 completes the closing operation is determined from the current distortion called the dip 25 (see FIG. 3) and the operating sound signal 23, and the time point d at which the 7 langier 2 completes the releasing action is determined from the operating sound signal 23. demand. Furthermore, assuming that the slope of the rise of the coil current from the time the coil current enters until it reaches a steady state is e (e = Lanθ), the amount of distortion of the dip 25 for the NG coil current 21 and the SC coil current 22 is expressed as the area f. Find it in shape. Note that the control signal 24 is used as a trigger signal to start analysis. Further, since it is believed that the analysis processing program will be easily understood by those skilled in the art from the above explanation and the following explanation, the flowchart thereof can be omitted.

Next, the criteria for extracting time points a - e from the above-mentioned signal waveform will be explained: (1) For time points a and b, appropriate levels that can be arbitrarily set are determined as the points at which the current signal cuts.

(2) Regarding time point C, in the case of lift coil current 2o, an appropriate time range that can be set arbitrarily is provided, and the time point C is determined as the first point exceeding an appropriate level that can be set arbitrarily within that range. In the case of the NG coil current signal 21 and the SG coil current signal 22, first, in order to accurately extract the characteristics of the coil current, the alternating current component or noise component found in the signal waveform is removed by a filter device (not shown). Next, find the time point where the coil current first takes a minimum value in the interval from time point a when it is turned on to time point a when it turns off, and if there is an operating sound at the same time point, the plunger will close this time point. The presence or absence of an operating sound is determined by setting a time width of approximately ±5 m5ec at the same time point to extract the time of occurrence of the operating sound corresponding to the operation of each plunger. Judgment is made based on whether there is an operating sound signal that exceeds an appropriate level that can be arbitrarily set within the range of .

Regarding the removal of alternating current components, it is possible to pass the signal through a mechanical filter device as pre-processing, but in order to maintain synchronization with other signals, the signal is filtered at three points after being taken into the arithmetic processing unit 16. It may be removed by a digital filter using successive averaging.

(2) For time point d, similarly, set an appropriate time width and level that can be arbitrarily set, and find it as the first point at which the operating sound signal exceeds that level.

(2) The slope e of the rise of the current signal is determined as the slope of the straight line connecting the time point a and the points where each coil current signal becomes 30%, 50%, and 70% of the steady current value.

■ The area f of dip 25 is the filtered MC
For each coil and SC coil, the area is determined as the area surrounded by the current waveform and a straight line drawn parallel to the time axis from the point that takes the maximum value before time point C.

Next, the time points a to d extracted according to the above criteria are:
Various characteristics associated with the plunger operation are converted into the following time differences and output to the CRT display device tf17 and/or printer/plotter 18. FIG. 48 shows a specific example of the analysis results of the above-mentioned characteristics.

TLin: Time difference between point a and point 0 of the lift coil, which represents the time it takes for the lift plunger to close after the lift coil current is turned on TLout: The time it takes for the lift plunger to release after the lift coil current is turned off. Time difference TMin between point b and point d of the lift coil, which represents time: M
Time difference between points TMout: Time difference between points b and d of the MC coil, which represents the time from when the MG coil current is turned off until the release operation of the NG plunger is completed.TSin: After the MC coil current is turned on, the SC plunger closes. Time difference between point a and point 0 of the SC coil, which represents the time until TSout: Time difference between point b and point d of the MC coil, which represents the time from when the coil current is cut off at S until the release operation of the SC plunger is completed dTsM :0 point of the SC coil and MC representing the time from when the SC plunger closes until the MG coil current is cut off.
Time difference dTMs between point b of the coil: 0 point of the MC coil and SC, which represents the time from when the MG plunger closes until the MC coil current is cut off
Time difference between point b of the coil dTLM:) 4tl: 1 Time difference between point d of the MC coil and point d of the lift coil, which represents the time from the completion of the release operation of the 1 plunger to the completion of the release operation of the lift plunger Also, these characteristics TLin , TLout, TMi
n, TMout, etc. can be output as a trend diagram shown in the 4th BIJ so that their temporal changes can be easily determined, and by further performing statistical processing,
Variations in the operating conditions of the individual fy control rod drives CRDH can also be displayed as a histogram shown in FIG. 4C.

[Effect of the invention] Therefore, when the motion analysis device according to the present invention is used, sI
T-bar drive system [CHDH's coil current signal and operation sound signal characteristic analysis work can be performed automatically and quickly with less labor, and can also prevent individual differences in manual judgment and human errors. , it is possible to improve the reliability of analysis results.

Furthermore, since the analysis work is performed at high speed as described above, the operational status of the control rod drive device CHDH can be monitored in real time, making it possible to respond quickly and appropriately in the event of an abnormality.

Furthermore, by regularly analyzing CRDM operation signals using CHDM operation confirmation tests during periodic inspections and monthly inspections during nuclear power plant operation, and performing statistical processing, CRD
It can also be used for preventive maintenance of the M drive system.

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view showing the operation analysis device according to the present invention connected to a control rod drive device, and FIGS. 2(a), (b), (
c) and (d) are graphs showing the signal waveforms and extracted information of each coil current and operation sound input to the operation analysis device of the present invention, and (a) and (b) of FIG. Graphs showing the current signals and extracted information in FIGS. 2(b) and (e) after multiplication, and FIG. Graphs that display analysis results of various features superimposed on the input signals of FIGS. 2(a), (b), (e), and (d); FIG. 4B (a), (b), and (c)
is a graph displaying some of the analysis results of the characteristics shown in Fig. 48 as a trend, and Fig. 4C (a) and (b) are
FIG. 5, which is a graph showing the average analysis value for each control rod drive device and displays the distribution as a histogram, is a sectional view showing the schematic structure of a control rod drive device for a pressurized water reactor. CRD...υr control rod drive device 5... Control device (CRDM control panel) 6... Electromagnetic coil for lifting (lift coil) 7... Electromagnetic coil for movable gripper (NG coil) 8... Fixed Gripper electromagnetic coil (SC coil) 11... Operating sound detector (accelerometer) 14... Buffer amplifier 15.
...Preprocessing device 16... Arithmetic processing device 20.21
．． 22... Current signal 23... Detection signal (operating sound signal) 24... Control signal

Claims (1)

[Scope of Claims] An operation analysis device for an electromagnetic control rod drive device, comprising an electromagnetic coil for lifting and lowering, an electromagnetic coil for a fixed gripper, and an electromagnetic coil for a movable gripper, which are operated by a control signal from a control device. , a detector connected to the control rod driving device to detect its operating sound; a current signal from each of the lifting electromagnetic coil, the fixed gripper electromagnetic coil, and the movable gripper electromagnetic coil; a buffer amplifier that receives a detection signal of the current signal and the control signal from the control device; a preprocessing device that digitizes each of the current signal, the detection signal, and the control signal; An operation analysis device for an electromagnetically driven control rod drive device, comprising: an arithmetic processing device that analyzes and processes operation specifications;