JP2019145348A - Diagnostic method of operation abnormality in power switch - Google Patents

Abstract

To provide a diagnostic method of operation abnormality in power switch capable of understanding operation abnormality of the power switch exactly with simple configuration.SOLUTION: In the diagnostic method of operation abnormality in a circuit breaker, a microphone for measurement is placed, at first, around the circuit breaker, and operation sound when opening and closing the circuit breaker is measured by the microphone for measurement. Subsequently, a map indicating relationship of frequency and time is created by conventional method of fast Fourier transformation (FFT), based on a graph indicating the relationship of the measured sound pressure and time. On the basis of the number of peaks appearing in the map thus obtained or the position of the peak, operation abnormality of the circuit breaker can be discriminated. For example, peak is only one during normal time of the circuit breaker, but two peaks 24 appear in the case of OFF operation abnormality. In the case of ON operation abnormality of the circuit breaker, position of the peak 24 is different from that during normal time.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a power switch capable of easily and accurately diagnosing the occurrence of an operation failure of non-operating or open non-operating in a circuit breaker as a power switch used in, for example, a substation. The present invention relates to a method for diagnosing an abnormal operation in the system.

  When an abnormal operation of turning on / off or an abnormal operation of opening / disengaging occurs in a circuit breaker at a substation, it is necessary to identify the abnormal part and implement countermeasures. In order to detect such an abnormal operation of the circuit breaker, the circuit breaker is detected by detecting the operation sound when the circuit breaker operates, detecting the propagation acceleration of the operation sound, or detecting the vibration during operation. A method for managing the operation status of the vessel is being studied.

  This type of circuit breaker monitoring device is disclosed in Patent Document 1, for example. This circuit breaker monitoring apparatus includes a circuit breaker command signal receiving unit that receives a signal for starting operation of a circuit breaker, an acoustic sensor that detects an operation sound of the circuit breaker, and a circuit breaker command signal and an acoustic sensor received by the circuit breaker command signal receiving unit. And a calculation unit that calculates an operation time until the circuit breaker operates based on the operation sound detected by the computer.

JP 2007-273157 A

  In the breaker monitoring device of the conventional configuration described in Patent Document 1 described above, the break command signal receiving unit receives the break command signal, and the acoustic sensor detects the operation sound of the breaker, and compares both signals. Thus, the operation time of the circuit breaker must be calculated by the calculation unit. Moreover, since the operating time of the obtained circuit breaker varies depending on the distance between the circuit breaker and the acoustic sensor, it is necessary to make a comparative study with the conventional method from the viewpoint of setting a threshold value and increasing measurement accuracy. For this reason, there existed a problem that the structure of a monitoring apparatus became complicated and it was difficult to grasp | ascertain correctly the abnormal operation of a circuit breaker.

  Accordingly, an object of the present invention is to provide a method for diagnosing an operation abnormality in a power switch capable of accurately grasping the operation abnormality of the power switch with a simple configuration.

  In order to achieve the above object, in the method for diagnosing an operation abnormality in a power switch according to the present invention, a measurement microphone is arranged around the power switch to measure an operation sound when the power switch is opened and closed. Measure with a microphone. And based on the graph which shows the relationship between the measured sound pressure and time, the map which shows the relationship between a frequency and time by a fast Fourier transform is created, and based on the number of peaks which appeared in the map, or the position of a peak An operation abnormality of the power switch is determined.

  For this reason, it is only necessary to perform a simple operation of measuring an operation sound when the power switch is opened and closed with a measurement microphone, and creating a map showing the time change of the frequency from the time change of the obtained sound pressure. Then, the abnormal operation of the power switch can be easily and accurately determined based on the number of peaks or the position of the peaks appearing on the map.

  According to the operation abnormality diagnosis method for the power switch of the present invention, there is an effect that the operation abnormality of the power switch can be accurately grasped with a simple configuration.

In embodiment of this invention, it is a map which shows the relationship of the frequency and time at the time of the operation | movement abnormality of a circuit breaker, (a) is a map which shows a cutting operation abnormality, (b) is an input operation abnormality in which only a trigger operates. (C) is a map showing an input operation abnormality in which the link operation is performed but the latch is not engaged. It is a map which shows the relationship between the frequency at the time of the normal operation of a circuit breaker, and time, (a) is a map which shows the time of cutting operation, (b) is a map which shows the time of on operation. Schematic explanatory drawing which shows the positional relationship of a circuit breaker and a measurement microphone. It is explanatory drawing which shows the operation process of a circuit breaker, (a) is explanatory drawing which shows the operation process at the time of cutting operation, (b) is explanatory drawing which shows the operation process at the time of on-operation. (A) is a schematic perspective view showing a state in which the cover of the circuit breaker is removed, (b) is a schematic perspective view showing a state in which the cover of the circuit breaker is attached, and (c) is a cover attached to the circuit breaker and further protecting it. The schematic perspective view which shows the state which covered the cover. (A) is a normal map with the circuit breaker cover removed, (b) is a normal map with the circuit breaker cover attached, (c) is a circuit breaker cover, and Normal map with a protective cover on it. (A) is a map at the time of an abnormal cutting operation with the circuit breaker cover removed, (b) is a map at the time of an abnormal cutting operation with the circuit breaker cover attached, and (c) is a cover on the circuit breaker. Is a map when the cutting operation is abnormal with a protective cover attached. The characteristic view which shows the relationship between a sound pressure level and time about the time of normal of a circuit breaker, and the time of cutting operation abnormality. The characteristic view which shows the relationship between a sound pressure level and time about the time of the normal of a circuit breaker, and the time of two entrance operation | movement abnormalities. (A) is a static environment with little reverberation, a characteristic diagram showing the relationship between sound pressure level and time when the measurement microphone is close to the circuit breaker cover, (b) is a static environment, and the measurement microphone is A characteristic diagram showing the relationship between sound pressure level and time when the circuit breaker cover is removed at a remote position, (c) is a static environment, sound pressure level and time when the cover is attached at a close position (D) is a characteristic diagram showing the relationship between the sound pressure level and time when a cover is attached to the circuit breaker at a distant position in a static environment, (e) is a cut off at a static environment, a close position (F) is a characteristic diagram showing the relationship between the sound pressure level and time when a cover is attached to a breaker and a protective cover, and (f) is a circuit breaker with a cover in a static environment and at a remote position. Shows the relationship between sound pressure level and time Characteristic diagram. (A) Characteristic diagram showing the relationship between sound pressure level and time when the circuit breaker cover is removed at a close position with a lot of reverberation. (C) is a characteristic diagram showing the relationship between sound pressure level and time when a cover is attached to the circuit breaker at a close position, (c) (d) is a characteristic diagram showing the relationship between sound pressure level and time when a cover is attached to a circuit breaker in a reverberant environment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
As the circuit breaker as the power switch of this embodiment, for example, a known 6.6 kV electric spring type vacuum circuit breaker used for 30 years is used. In this circuit breaker, an electric motor is provided in the circuit breaker body, and a spring that is stored by activation of the electric motor is provided. Further, the breaker body is provided with a link connected to the spring in conjunction with the main circuit, and is stopped by a stopper at the breaking completion position in the cutting operation. Further, the link engages with the latch at the closing completion position in the closing operation, and maintains the closing state.

  Specifically, as shown in FIG. 4A, when the main circuit of the circuit breaker is turned off, the trigger operation 11 such as a command signal (control current signal) is performed through the spring release 12 and the link operation 13. Stopped by the stopper 14 and the main circuit is turned off 15. On the other hand, as shown in FIG. 4B, when the main circuit of the circuit breaker is turned on, it is latched and engaged 19 through the spring release 17 and the link operation 18 by the trigger operation 16 such as a command signal. Is input 20. After the main circuit turning operation 15 and the turning operation 20, the released spring is stored by the electric motor.

  When the main circuit is turned off 15, an operation noise is generated when the spring release 12, the link action 13 and the stopper 14 are stopped 14. Operation noise is generated when These operation sounds are continuously generated in a short time.

  As shown in FIG. 3, in order to measure this operation sound, a position spaced forward from the circuit breaker 21, for example, a position where the short distance D from the circuit breaker 21 is 5 cm, or a long distance L from the circuit breaker 21. The measurement microphone 22 is arranged at a position of 50 cm. As the measurement microphone 22, for example, a 1/2 inch microphone or a 1/4 inch microphone of Ono Sokki Co., Ltd. having excellent frequency characteristics is used. The operation sound of the circuit breaker 21 can be measured by the measurement microphone 22 and the characteristics of the operation sound can be analyzed.

Next, a method for diagnosing abnormal operation in the circuit breaker 21 will be described.
In this operation abnormality diagnosis method, first, the measurement microphone 22 is arranged around the circuit breaker 21, and the operation sound when the circuit breaker 21 is opened and closed is measured by the measurement microphone 22. Next, a map showing the relationship between frequency (Hz) and time (s) by the usual method of fast Fourier transform (FFT) based on a graph showing the relationship between measured sound pressure (Pa) and time (s) ( Color map). That is, the time change of the sound pressure characteristic is converted into the time change of the frequency characteristic in accordance with the usual FFT method. This map is created by software for editing and analyzing sound pressure time-series data by a conventional method, for example, analysis software Oscope2 of Ono Sokki Co., Ltd. The abnormal operation of the circuit breaker 21 can be determined based on the number of peaks appearing on the map or the temporal position of the peaks.

  As shown in FIG. 2A, in the normal state, when the circuit breaker 21 is turned off, one peak 23 appears as indicated by a two-dot chain line in the map indicating the relationship between frequency and time. Further, as shown in FIG. 2 (b), during normal operation, when the circuit breaker 21 is turned on, one peak 23 appears as indicated by a two-dot chain line in the map, and the peak 23 is from 100 ms. Located in front. In the maps shown in FIGS. 2 (a) and 2 (b), the numerical value on the right vertical axis represents the color index. The closer to 105 or 110, the more red the color is, and the closer to 25 or 40, the more black. Since the map is a color map, the number and positions of the peaks 23 can be easily recognized visually. 2A and 2B are attached to the property submission form.

  On the other hand, as shown in FIG. 1A, two peaks 24 appear as indicated by a two-dot chain line in the map when the breaking operation of the circuit breaker 21 is abnormal. For this reason, it is possible to determine the cutting operation abnormality by the number of peaks 24 appearing in the map.

  Also, as shown in FIG. 1 (b), the peak 24 position from 25 ms as indicated by the two-dot chain line in the map when the breaker 21 is turned on and only the trigger is turned on. Located in front. Further, as shown in FIG. 1 (c), the position of the peak 24 as indicated by the two-dot chain line in the map when the input operation abnormality of the circuit breaker 21 does not engage the latch after the link operation. Is located after 100 ms. For this reason, it is possible to determine the abnormality of the input operation by the position of the peak 24 appearing in the map.

  Since the maps in FIGS. 1A to 1C are color maps, the number and positions of the peaks 24 can be easily recognized visually. In addition, the color map of Fig.1 (a)-(c) is attached to the property submission.

  Next, when the cover of the circuit breaker 21 is removed as shown in FIG. 5A (inspection state) A, when the cover 25 is put on the circuit breaker 21 as shown in FIG. As shown in (c), when the circuit breaker 21 was covered with the cover 25 and housed in the protective box 26 (normal operation state) C, the breaking operation abnormality of the circuit breaker 21 was examined.

  In the case of A shown in FIG. 6A, in the case of B shown in FIG. 6B and in the case of C shown in FIG. 6C, the peak 23 in the map is in any case when the circuit breaker 21 is normal. One will also appear. On the other hand, in the case of A shown in FIG. 7A, in the case of B shown in FIG. 7B and in the case of C shown in FIG. Appears in both cases.

  As described above, regardless of the presence or absence of the cover 25 or the protective box 26 of the circuit breaker 21, it is possible to easily determine the abnormal operation of the circuit breaker 21 based on the number of peaks using the aforementioned map.

  When it is determined that the circuit breaker 21 has a switching operation abnormality or an input operation abnormality as described above, the circuit breaker 21 is narrowed down to a specific frequency, for example, a frequency of 13 to 15 kHz band, and the sound is sounded by an ordinary method of the fast Fourier transform (FFT). A characteristic diagram showing the relationship between the pressure level (dB) and time (ms) is created. This characteristic diagram is for converting the time change of the sound pressure characteristic into the time change of the sound pressure level characteristic according to the usual method of FFT. This conversion is performed by, for example, the analysis software of the above Ono Sokki Co., Ltd. The specific frequency is a frequency band different from a resonance frequency near 11.5 kHz, which is characteristic of metal as a natural vibration frequency of the circuit breaker 21, and a frequency of a local vibration sound (noise) of 19 kHz or more, that is, measurement of an operating sound. This is a frequency band suitable for performing accurately.

  The solid line shown in FIG. 8 is a waveform when the circuit breaker 21 is in a normal state, and one peak 27 having a sound pressure level of 85 dB or more appears. On the other hand, as shown by the broken line in FIG. 8, in the case of the abnormal operation of the circuit breaker 21, two peaks 28 with a sound pressure level of 85 dB or higher appear, and the sound pressure level after 200 ms is 150% or higher when normal. It is. For this reason, by setting an appropriate threshold value for the normal value for the sound pressure level, it is possible to accurately determine the abnormal operation of the circuit breaker 21. In addition, the operation sound was measured twice each at normal time and when the cut operation was abnormal.

  Moreover, as shown by the solid line in FIG. 9, the normal operation waveform of the circuit breaker 21 is represented, and two peaks 27 having a sound pressure level of 85 dB or more appear. On the other hand, as shown by the thick broken line in FIG. 9, in the case of an input operation abnormality in which only the trigger of the circuit breaker 21 operates, the waveform 29 does not have a peak with a sound pressure level of 85 dB or more, and the sound pressure level after 200 ms. It is 10% or less of the normal time.

  Furthermore, as shown by a thin broken line in FIG. 9, in the case of an abnormal input operation in which the latch engagement is not performed after the link operation of the circuit breaker 21, three peaks 28 having a sound pressure level of 85 dB or more appear, and the sound pressure level after 200 ms. Is 115% or more of normal. For this reason, by setting an appropriate threshold for the sound pressure level with respect to the normal value, it is possible to accurately determine whether or not the circuit breaker 21 is turned on. In addition, the operating sound was measured twice each time during normal operation and when the input operation was abnormal.

  Thus, the abnormal operation of the circuit breaker 21 or the abnormal operation of the circuit breaker 21 is clearly determined on the basis of the peak number or the threshold value of the sound pressure level using the characteristic diagram showing the relationship between the sound pressure level and the time. Can do.

  Next, with respect to the measurement environment of the operating sound, the measurement microphone 22 is located at a position where the short distance D is 5 cm (near position) from the circuit breaker 21 in an environment with little reverberation (static environment) and an environment with much reverberation (sound environment). The case where the long separation distance L is 50 cm (far position) and the circuit breaker 21 is A, B, and C were examined.

  FIG. 10A shows the case of A in the static environment and the near position, FIG. 10B shows the case of A in the static environment and the far position, and FIG. 10C shows the case of B in the static environment and the close position. FIG. 10 (d) shows the case of B in the static environment and the far position, FIG. 10 (e) shows the case of C in the static environment and the near position, and FIG. 10 (f) shows the static environment and the far position. The case of C at the position is shown. 11 (a) shows the case of A at the reverberant environment, near position, FIG. 11 (b) shows the case of A at the reverberant environment, far position, and FIG. 11 (c) shows the case of the reverberant environment, near position. The case of B is shown, and FIG. 11 (d) shows the case of B in a reverberant environment and a distant position.

  In FIGS. 10A to 10F and FIGS. 11A to 11D, the solid line represents the waveform 30 in the normal state, and the broken line represents the waveform 31 of the cutting operation abnormality. The waveform 30 and the waveform 31 are the results of measuring the operating sound twice.

  By comparing these FIGS. 10A to 10F and FIGS. 11A to 11D, the reverberant environment tends to more easily determine the operation abnormality of the circuit breaker 21 than the static environment. 10 (a) and FIG. 10 (b), FIG. 10 (c) and FIG. 10 (d), FIG. 10 (e) and FIG. 10 (f), FIG. According to the comparison between a) and FIG. 11 (b) and the comparison between FIG. 11 (c) and FIG. 11 (d), the position of the measurement microphone 22 is more abnormal at the far position than at the near position. It was easy to distinguish.

Next, a specific procedure for diagnosing abnormal operation of the circuit breaker 21 will be described.
1) The operation sound in the normal state of the circuit breaker 21 is measured and an initial pattern is held.
2) With respect to the circuit breaker 21 that has been used for many years, the operation sound of the circuit breaker 21 in the energized state is measured with the measurement microphone 22 permanently installed in the circuit breaker 21 or the measurement microphone 22 brought by the measurer.

3) The measurement data is analyzed by an analysis device, and qualitatively determined by comparison with an initial pattern or comparison of an abnormal pattern based on the map.
4) If it is determined in 3) that there is an abnormal operation, the state of the abnormal operation is compared with a threshold value based on a characteristic diagram showing the relationship between the sound pressure level and time by narrowing down to a specific frequency. to decide.

5) The circuit breaker 21 determined to have an abnormal operation is inspected and maintained after a power failure.
Next, an effect | action is demonstrated about the operation abnormality diagnosis method in the circuit breaker 21 of this embodiment.
When diagnosing an abnormal operation of the circuit breaker 21, a measurement microphone 22 is disposed around the circuit breaker 21 to measure an operation sound generated when the circuit breaker 21 is opened and closed. Then, based on a graph showing the relationship between the measured sound pressure and time, a map showing the relationship between frequency and time is created by FFT. Based on the obtained map, it is possible to qualitatively determine the abnormal operation of the circuit breaker 21 based on the number of peaks or the position of the peaks appearing on the map. Since this map is a color map, the number and positions of peaks can be quickly recognized visually.

  After the operation abnormality of the circuit breaker 21 is qualitatively determined in this way, when the operation abnormality is more clearly determined, the characteristic indicating the relationship between the sound pressure level and the time by FFT after narrowing down to a certain range of frequencies. Create a diagram. Then, from the obtained characteristic diagram, it is possible to accurately determine the abnormal operation of the circuit breaker 21 based on the number of peaks in the characteristic diagram and the sound pressure level based on the threshold value set with reference to the normal state.

The effect exhibited by the above embodiment is described collectively below.
(1) In the method for diagnosing abnormal operation in the circuit breaker 21 of this embodiment, the measurement microphone 22 is arranged around the circuit breaker 21 and the operation sound when the circuit breaker 21 is opened and closed is measured by the measurement microphone 22. Next, a map showing the time change of the frequency characteristic is created by FFT based on the obtained graph showing the time change of the sound pressure characteristic. Then, the abnormal operation of the circuit breaker 21 can be determined based on the number of peaks appearing on the map or the peak position.

  For this reason, a map can be created easily and quickly from the data of the operation sound obtained by the measurement microphone 22, and the operation abnormality of the circuit breaker 21 can be easily determined by the peak appearing on the map.

Therefore, according to the diagnosis method of the embodiment, the operation abnormality of the circuit breaker 21 can be accurately grasped with a simple configuration.
(2) In the power switch, the trigger operation 11 releases the spring 12 and the link operation 13 stops with the stopper 14 so that the main circuit is turned off 15. The trigger operation 16 latches the spring release 17 and the link operation 18 A spring-operated circuit breaker 21 in which the main circuit is engaged 20 by engaging 19. By measuring the operation sound at the time when the breaker 21 is turned off and when the breaker 21 is turned on, it is possible to easily determine whether the breaker 21 is turned off or turned on.

  (3) The measurement microphone 22 is disposed at a position separated from the circuit breaker 21. In this case, it is possible to accurately measure the operation sound of the circuit breaker 21 with the measurement microphone 22 while avoiding noise such as vibration sound of the circuit breaker 21. Furthermore, it is possible to determine an abnormal operation of the circuit breaker 21 without hindering the operation of the circuit breaker 21 in the normal operation state.

  (4) When there are two peaks appearing on the map, it is determined that the cutting operation is abnormal, and when the peak is located before 25 ms, it is determined that the input operation is abnormal in which only the trigger operation is performed. When the peak is located after 100 ms, it is determined that the input operation is abnormal because the latch engagement is not performed after the link operation. For this reason, it is possible to easily determine the abnormal operation of the circuit breaker 21 based on the number of peaks appearing on the map or the positions of the peaks.

  (5) A characteristic diagram showing the relationship between the sound pressure level and time is created by the FFT, and the circuit breaker 21 is controlled by the sound pressure level based on the threshold value set based on the number of peaks and the normal time in the characteristic diagram. Determine abnormal operation. Therefore, by creating a characteristic diagram of the sound pressure level and time, it is possible to accurately determine an abnormal operation of the circuit breaker 21 based on the number of peaks appearing in the characteristic diagram and an arbitrarily set threshold value. .

  (6) The characteristic diagram is created based on the operation sound in a frequency band different from the resonance frequency peculiar to the metal as the natural vibration frequency of the circuit breaker 21 and the frequency of the local vibration sound. Specifically, the frequency band is a frequency band of 13 to 15 kHz. For this reason, it is not obstructed by the natural vibration frequency or noise frequency of the circuit breaker 21, and the reliability of the characteristic diagram can be improved.

It should be noted that the embodiment described above can be modified and embodied as follows.
If the abnormal operation of the circuit breaker 21 can be accurately determined using the map, the creation of a characteristic diagram showing the relationship between the sound pressure level and time may be omitted.

The measurement microphone 22 may be disposed at a side position of the circuit breaker 21 or at a rear position.
As the circuit breaker 21, a circuit breaker in which the spring of the electric spring type vacuum circuit breaker is changed to a structure that operates by hydraulic pressure or air may be used.

  A switch such as a switch or a disconnector may be used as the power switch.

DESCRIPTION OF SYMBOLS 11 ... Trigger operation, 12 ... Spring release, 13 ... Link operation, 14 ... Stop by stopper, 15 ... Main circuit cut-off operation, 16 ... Trigger operation, 17 ... Spring release, 18 ... Link operation, 19 ... Latch engagement, 20 ... main circuit is turned on, 21 ... circuit breaker, 22 ... measurement microphone.

Claims (7)

  A measurement microphone is placed around the power switch, the operation sound when the power switch is opened and closed is measured with the measurement microphone, and fast Fourier transform is performed based on the graph showing the relationship between the measured sound pressure and time. A method for diagnosing an abnormal operation in a power switch that creates a map showing the relationship between frequency and time by conversion and discriminates the abnormal operation of the power switch based on the number of peaks or the position of the peak appearing in the map .   The power switch releases the spring by the trigger operation, stops at the stopper by the link operation, and the main circuit is turned off. On the other hand, the spring is released by the trigger operation, and the main circuit is turned on by the latch engagement by the link operation. The method for diagnosing abnormal operation in a power switch according to claim 1, wherein the circuit breaker is a spring-operated circuit breaker.   The method for diagnosing an operation abnormality in the power switch according to claim 1, wherein the measurement microphone is disposed at a position separated from the power switch.   When there are two peaks appearing on the map, it is determined that the cutting operation is abnormal, and when the peak is located before 25 ms, it is determined that the triggering operation is performed and only the trigger operation is performed. 4. The method for diagnosing an operation abnormality in a power switch according to claim 2, wherein when the position is after 100 ms, it is determined that the input operation is abnormal without latch engagement after the link operation.   A characteristic diagram showing the relationship between the sound pressure level and time is created by the fast Fourier transform, and the power switch according to the sound pressure level based on the threshold value set based on the number of peaks and the normal time in the characteristic diagram. The method for diagnosing an operation abnormality in a power switch according to claim 1, wherein the operation abnormality is determined.   The characteristic diagram is created based on an operating sound in a frequency band different from a resonance frequency peculiar to a metal as a natural vibration frequency of a power switch and a frequency of a local vibration sound. For diagnosing abnormal operation in electric power switches. The method for diagnosing an operation abnormality in a power switch according to claim 6, wherein the frequency band is a frequency band of 13 to 15 kHz.