JPH0954186A - Operation analyzer for control rod drive device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately analyze the operating status of an electromagnetic drive jack type control rod drive device by providing a dip detection processor and an operation sound detection processor, etc. SOLUTION: A dip detection processor performing an inflection point processing including a differential processing 33, an absolute value conversion 35, noise separation 37 and the like and an original wave processing against an original waveform 31 of current signal indicating the current value of electromagnetic coil, and an operation sound detection processor performing a waveform extraction processing and an operation sound detection processing against an output signal of an operation sound detector. By this, a latch operation point is clearly analyzed and detected by applying the inflection point processing including the differential processing to the coil current signal, even if the dip shape appearing in the electromagnetic coil current is a little unclear. Also, as wave form processing is applied to the output signal of the latch operation sound detector indicating the operation of the latch in a different manner and the output signal is processed in accordance with the waveform, the operation point is more accurately detected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for driving a control rod of a nuclear reactor, and more particularly, to remotely control the operating condition of an electromagnetically driven jack type control rod driving apparatus used in a pressurized water reactor. It relates to a device for analysis.

[0002]

2. Description of the Related Art Since a control rod of a nuclear reactor controls a nuclear reaction in the nuclear reactor, a device for driving the control rod of the nuclear reactor, a so-called control rod driving device, is used to safely operate the nuclear reactor. It is an extremely important device. Therefore, it is general to provide a device for constantly monitoring the operating condition during the operation and obtaining information for preventing the occurrence of a defect. Control rod drive devices include those that use water pressure and those that use the rotational force of an electric motor, but in a pressurized water reactor, which is a type of light water reactor, an electromagnetically driven jack type may be used. Many. Conceptually speaking, this electromagnetically driven jack type drive device drives the jack shaft in the axial direction by an electromagnetically driven latch.

An example of a typical structure of an electromagnetically driven jack type control rod drive device is shown in FIG. To briefly explain this, a drive shaft 5 is arranged in a guide tube 3 which is connected to the upper lid 1 of the reactor vessel and stands upright. The drive shaft 5 is connected at its lower end to a control rod (not shown). The drive shaft 5 is formed with a plurality of circumferential grooves 5a at a predetermined axial pitch. A housing 13 in which three coils, that is, an elevating coil 7, a movable gripping coil 9 and a fixed gripping coil 11 are packaged, is provided surrounding the guide tube 3. The movable gripping coil 9 drives a movable gripping mechanism having a latch 15, a link 17, and a plunger 19, and this movable gripping mechanism grips the drive shaft 5 vertically using the circumferential groove 5a. The elevating coil 7 ascends and descends by one pitch (1 step) while the movable gripping mechanism holds the drive shaft 5 so that the drive shaft 5 is raised or lowered step by step by repeating excitation. The fixed gripping coil 11 drives a fixed gripping mechanism having a latch 21, a link 23 and a plunger 25, which intermittently grips the drive shaft 5 in a vertically immovable position. The movable gripping coil 9, the lifting coil 7, and the fixed gripping coil 11 are sequentially excited, and if this is repeated, the drive shaft 5 moves intermittently, and the control rod connected to the drive shaft 5 is moved to the reactor vessel. Insert into or pull out of the core.

The operation of the electromagnetically driven jack type control rod driving device as described above is associated with the exciting current of each coil, as shown in FIG.
This will be described with reference to FIG. In FIG. 11, an operation command control signal E to which a command signal for the control rod drive device to move the drive shaft 5 by one step is input as a step input, a lifting coil current A, a movable gripping coil current B, and a fixed gripping coil current C. , And the latch operation sound detection waveform signal D is illustrated with the time axis as the horizontal axis. The above-mentioned 1 (raising) operation of the control rod drive device will be explained in association with changes in the current value of each of these coils. When the drive shaft 5 is stationary, the latch 21 of the fixed gripping mechanism holds the drive shaft 5, so that the fixed gripping coil 11 is excited and the fixed gripping coil current C flows. b. When the step operation signal is input as the control signal E, the movable gripping coil current B rises (point a), and the latch 15 grips the drive shaft 5 (point c). c. The fixed gripping coil 11 is demagnetized, the fixed gripping coil current C decreases (point b), and the latch 21 separates from the drive shaft 5 (point d). d. The lifting coil current A flows, the lifting coil 7 is excited, and the drive shaft 5 gripped by the latch 15 is pulled up by one step (point a to point c). e. Fixed grip coil 11 The fixed grip coil 11 is supplied with a current C.
Is excited, the latch 21 is engaged with the drive shaft 5, and this is grasped (point a to point c). f. When the movable gripping coil current B is cut off (point b) and the movable gripping coil 9 is demagnetized, the latch 15 separates from the drive shaft 5. At the same time, the lifting coil current A is turned off (b), and the lifting coil 7 is demagnetized. g. When the step signal of the control signal E is completed, the fixed gripping coil current C returns to the initial state, and the latch 21 holds the drive shaft 5.

Since the current of each electromagnetic coil of the electromagnetically driven jack type control rod drive device changes during operation as described above,
The prior art for monitoring the operating condition of this control rod drive is to monitor these currents and analyze the operation. When the latches 15 and 21 of each gripping mechanism are activated and engage with the drive shaft 5, a considerable impact is generated, so that the detector 27 is fixed on the upper end of the guide tube 3 (see FIG. 1).
0), the detection signal is used as the latch operation sound detection waveform signal D (FIG. 11). Further, as can be seen from FIG. 11, when the control rod drive device is operating normally, when the movable gripping coil 9 and the fixed gripping coil 11 are excited, the latches 15 and 21 pivot to drive the drive shaft 5. The movable gripping coil current B and the fixed gripping coil current C exhibit unique waveforms when engaging and engaging the circumferential groove 5a. FIG. 12 shows modeled characteristic waveforms of the movable gripping coil current B and the fixed gripping coil current C, and points c of each curve.
In the vicinity of, the engagement phenomenon appears in the form of a dip (dent).

Under the above-mentioned premise, the operation analysis for monitoring is performed as follows. A. The operation command control signal E is accurately discriminated by the computer as a step input signal. I. Since the latch operation sound detection waveform signal D has a large peak value during operation, a threshold value is set and the operation of the latch is detected when the threshold value is exceeded. The threshold value is set empirically. C. The excitation point a and the demagnetization point b of each coil are defined as the points where the current signal cuts the arbitrarily set level points. D. At the moment when the latches 15 and 21 actually latch the drive shaft 5, each coil current changes as shown around the point c to form a dip, so the operation is detected from this figure. Movable gripping coil current B and fixed gripping coil current C
12 is modeled by removing AC components and noise components with a filter device (not shown), as shown in FIGS. 12 (i) and 12 (ii). The waveforms near the point c of both coil currents B and C are extracted and shown in FIG. 12 (iii). Referring to this figure, after a certain time (t ₀ ) has passed from the point a, the data is compared at every minute time, the slope is obtained, and the point which becomes negative at the beginning is set as the maximum point m, and further advance is performed first. The point that becomes positive is the minimum point n. When the difference h exceeds the judgment value and the peak value of the latch operation sound waveform signal D exists in the dip, the minimum point n is defined as the point c. This point c is regarded as the point (time) when the latches 15 and 21 are activated. E. In this way, the excitation point, demagnetization point, operating point of the latch, and input point of the operation command control signal of each coil of the control rod drive device are analyzed and detected, so that the operating condition is analyzed. Become.

[0007]

However, the above-described motion analysis algorithm, which is the basis of the motion analysis, has the following problems. That is, a. The dips in the current signals of the movable gripping coil and the fixed gripping coil are detected by the height and time width of the dent, but when the dip shape is shallow or unclear,
It may become undetectable. b. The operating noise of the latch is detected by the peak signal of the detector (usually an accelerometer is used) installed at the top of the control rod driving device guide tube. However, when the operating noise is low or extremely high, it is a signal. Is shaken off. Further, in the case of overlapping waveforms, it cannot be detected. In spite of the above problems, there is a limitation that only the current signal of each coil and the operation sound detection waveform signal can be considered as graspable signals that represent the operation status of the electromagnetically driven jack type control rod drive device. . Therefore, an object of the present invention is to use the current signal of each coil having a dip indicating the operation of the latch of the electromagnetically driven jack type control rod drive device and the waveform signal indicating the operation sound by skillfully analyzing the signal, and the above-mentioned problems. It is an object of the present invention to provide an operation analysis device of a control rod drive device by an operation algorithm that solves

[0008]

In order to achieve the above object, according to the present invention, an apparatus for analyzing the operating condition of an electromagnetically driven jack type control rod drive device having a latch driven by an electromagnetic coil is provided as described above. A dip detection processing device that performs bending point processing and original waveform processing in parallel on a current signal that represents the current value of the electromagnetic coil, and waveform extraction processing and operation on the output signal of the operation sound detector attached to the control rod drive device. The operation sound detection processing device sequentially performs sound detection processing.
The control rod driving device includes a fixed gripping coil for holding the control rod in a fixed position and a movable gripping coil for movably holding the drive rod by one step, although the number of electromagnetic coils is not limited. The coil current signal is subjected to differentiation processing, data absolute value conversion, and noise separation processing in the bending point processing of the dip detection processing device. On the other hand, in the waveform processing, dip size detection and level determination are performed.
In the waveform extraction process of the operation sound detection processing device, the original waveform is subjected to absolute value conversion, noise separation is performed, data is integrated, and then differential processing is performed to extract the waveform. In the operation sound detection process, the peak value is detected according to the state of the waveform such as the one-shot waveform and the overlapping waveform.

[0009]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows a flowchart of processing of a dip detection processing device of an operation analysis device according to the present invention, in which an original waveform 31 of a coil current signal as shown in FIG. 2 is subjected to bending point processing and original waveform processing. In FIG. 2, in the original waveform 31, the dip 39 appears in the one-dot chain line circle. In the figure, the code D _P is the current value of the peak of the dip 39, the code D ₃ is the position of the valley on the time axis, the code D _H is the height of the dip 39, and the code D _L is the time of the peak and the valley. Distance (on axis). Further, ΔT is a time step when the differential processing is performed.

When the original waveform 31 is subjected to the differential processing 33 of FIG. 1, differential waveforms 41, 42 and 43 as shown in FIG. 3 are obtained. The differential waveform 41 is one-time differential processing, the differential waveform 42 is two-time differential processing, and the differential waveform 43 is three-time differential processing. Reference numeral D ₁ indicates the lower limit position of the differential waveform 41. When the absolute value conversion 35 of the flowchart of FIG. 1 is applied to the differential waveform 43, as shown in FIG.
5 is obtained. Then, the peak value is set to P _m , the noise margin N _m is subtracted, and the noise separation 37 is performed. In FIG. 4, reference numeral D _2, P _P is the lowest limit position in front of the peak value P _m respectively, the time axis position of the peak value P _m. On the other hand, in the original waveform processing of FIG. 1, the current value D _P , which is the size of the dip, and the time axis position D ₃ are detected by the same method as the conventional method.

Next, the lower limit position obtained as described above
A procedure for determining the presence or absence of a dip using D ₁ , D ₂ and the valley position D ₃ will be described with reference to the flowchart of FIG. Step S _A : D ₁ and D ₂ obtained in FIGS. 3 and 4 are compared, and when D ₁ <D ₂ , D ₁ = D _X and D _X1 = D _X −2ΔT
When D ₁ > D ₂ , D ₂ = D _X and D _X1 = D _X -2 △ T
Recalculate D _X1 to the original waveform processing (Fig. 1) and obtain D ₃ again. Step S _B : If D ₃ <D ₁ and D ₃ <D _2, it is determined that there is no dip. Step S _C : If there is no D ₁ > (D ₂ + △ T), D ₁ > (P _P + 3 △ T), it is judged that there is no dip. In step S _D D _H = 0, if the ΔT count C of the parallel part is C <2, it is judged that there is no dip. If the results of the steps S _E, S _B , S _C , and S _D are opposite, it is determined that there is a dip, and D ₃ is the dip position.

Next, a method of detecting the latch operation sound will be described with reference to the flowchart of FIG. 6 and the waveform change diagram of FIG. The output waveform signal from the operation sound detector is the original waveform 51.
As a pattern of this waveform, it enters into the processing device as shown in FIG.
As shown in, there are a single-shot type waveform, a single-shot overlapping type waveform, and a continuous overlapping type waveform. When these are subjected to absolute value conversion 53, the waveforms shown in the figure are obtained, and noise separation (noise cut)
Process 55. Noise margin used for noise separation
N _m is set empirically from the conventional data, but since it is conceptually shown in FIG. 7, when the data (value) integration 57 of the absolute value waveform of the portion exceeding it is performed, A data integration curve as shown in FIG. 7 is obtained for each mold waveform. The data integration curve is generally a curve that rises to the right because the previous value is added to the later value in terms of time. When the differential processing 59 is applied to this data integration curve, a differential processing curve is obtained.
As can be easily seen from FIG. 7, each differential processing curve has a shape corresponding to the shape of the original waveform, and each peak has peak values P ₁ , P ₂ , and P ₃ , and therefore these The position and size of is measured. This completes the process of extracting the operating sound waveform.

Next, the process of detecting the operating noise of the latch from the above extracted waveform will be described. First, the processing of the single-shot waveform and the single-shot overlapping waveform will be described with reference to FIGS. 6 and 8. First, maximum peak point detection 61 is performed using the above-mentioned differential processing curve. In the case of a single-shot waveform, the peak value is only P ₁ , and the maximum peak point P _M = P ₁ (a). For single overlap type waveform, P ₂ <0.9P ₁ if P _M = P ₁
If P ₂ > 0.9P _1, then P _M = P ₂ (b).
The subsequent processing is common to both waveforms, but the presence / absence check 53 of other peak points is performed. 30 of the maximum peak point P _M
The position P _0.3 of% is obtained (c), and the minimum value (temporally) before the position P _0.3 is set to P ₀ . 30 P _M from P ₀ to the rear
Find the position P _0.15 of% (d). If P _0.15 > noise margin N _m, it is determined that there is an operating sound, and the position on the time axis is the operating sound position. If P _0.15 <noise margin N _m, it is determined that there is no operating noise.

The operation sound detection process for the continuous overlapping waveform will be described. In FIG. 9, the maximum peak point is P ₁
And draw a line of 0.3P1. Draw a line in the allowable range ± Δx that cannot be determined as adjacent peaks from the P _M position on both sides. Δx is empirically determined from conventional data. ± △ is outside the x, and closest to P _M, similarly determine the second peak value P ₂ in excess of 0.3P _M, it obtains a third peak value, a peak value P ₃ . Let P _M be the peak value closest to the point x from the start point.
x is obtained empirically from conventional data. With respect to this P _M , the same processing as that described with reference to FIG. 8 is performed to determine the presence or absence of the operating noise and the position. In this way, according to the present embodiment, the current signal of the electromagnetic coil that drives the latch is differentiated to detect the minimum position, and the operation is determined even if the dip shape is not clear. Also, as for the latch operation sound, the operation sound is detected even when the waveform is small or the waveforms overlap.

[0015]

As described above, according to the present invention,
In the electromagnetically driven jack type control rod drive, even if the shape of the dip appearing in the electromagnetic coil current is slightly unclear,
By applying a bending point process including a differential process to the coil current signal, the latch operating point can be clearly analyzed and detected. In addition, since the output signal of the latch operation sound detector representing the operation of the latch in another mode is subjected to the waveform extraction processing and the output signal is processed according to the type of the waveform, the position of the operation can be detected more accurately. As a result, the operation analysis of the electromagnetically driven jack type control rod drive device can be accurately performed.

[Brief description of drawings]

FIG. 1 is a flowchart showing a processing procedure of a dip detection processing device which is a part of an embodiment of the present invention.

FIG. 2 is a graph showing an example of a coil current signal processed in the embodiment.

FIG. 3 is a graph showing a result of one process in the flowchart.

FIG. 4 is a graph showing a result of one process in the flowchart.

FIG. 5 is a flowchart showing a procedure of one process in the flowchart.

FIG. 6 is a flowchart showing a processing procedure of the operation sound detection processing device which is a part of the embodiment.

FIG. 7 is an explanatory diagram illustrating a processing flow of the flowchart of FIG. 6;

FIG. 8 is an explanatory diagram illustrating a processing flow of the flowchart of FIG. 6;

9 is an explanatory diagram illustrating a processing flow of the flowchart of FIG. 6;

FIG. 10 is a sectional view showing an example of a control rod drive device.

FIG. 11 is a graph showing a procedure of conventional analysis.

FIG. 12 is an explanatory diagram showing a procedure of conventional analysis.

[Explanation of symbols]

 31 original waveform 33 differential processing 35 absolute value conversion 37 noise separation 39 dip 41, 42, 43 differential waveform 45 absolute value waveform 51 original waveform 53 absolute value conversion 55 noise separation 57 data integration 59 differential processing

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshinori Takada 1-1-1 Wadazaki-cho, Hyogo-ku, Kobe-shi, Hyogo Mitsubishi Heavy Industries Ltd. Kobe Shipyard

Claims (1)

[Claims] 1. An apparatus for analyzing an operating condition of an electromagnetically driven jack type control rod driving apparatus having a latch driven by an electromagnetic coil, wherein the bending point processing is performed in parallel with a current signal representing a current value of the electromagnetic coil. And a source waveform processing and a dip detection processing apparatus, and an operation sound detection processing apparatus that sequentially performs waveform extraction processing and operation sound detection processing on the output signal of the operation sound detector attached to the control rod drive device. Operation analysis device for rod drive.