JP6965182B2 - Diagnosis method of operation abnormality in power switch - Google Patents

Description

INDUSTRIAL APPLICABILITY The present invention can easily and accurately diagnose that a circuit breaker as a power switch used in a substation or the like has an operation abnormality of input non-operation or open non-operation. Regarding the method of diagnosing the operation abnormality in.

When the circuit breaker of the substation has an operation abnormality of input non-operation or an operation abnormality of open non-operation, it is necessary to identify the abnormal part and take countermeasures. In order to detect such an operation abnormality of the circuit breaker, the operation sound when the circuit breaker is operated is detected, the propagation acceleration of the operation sound is detected, and the vibration during the operation is detected to interrupt the circuit breaker. A method of managing the operating status of the circuit breaker is being studied.

This type of circuit breaker monitoring device is disclosed in, for example, Patent Document 1. This circuit breaker monitoring device includes a circuit breaker command signal receiver that receives a signal to start the operation of the circuit breaker, an acoustic sensor that detects the operation sound of the circuit breaker, and a circuit breaker command signal and an acoustic sensor received by the circuit breaker signal receiver. It is equipped with a calculation unit that calculates the operation time until the circuit breaker operates based on the operation sound detected by.

Japanese Unexamined Patent Publication No. 2007-273157

In the circuit breaker monitoring device having the conventional configuration described in Patent Document 1 described above, the circuit breaker monitoring device receives the circuit breaker command signal at the circuit breaker command signal receiving unit, detects the operating sound of the circuit breaker with the acoustic sensor, and compares the two signals. Then, the operating time of the circuit breaker must be calculated by the calculation unit. Further, since the operating time of the obtained circuit breaker changes depending on the distance between the circuit breaker and the acoustic sensor, etc., it is necessary to compare with the conventional method from the viewpoint of setting a threshold value and improving the measurement accuracy. For this reason, there is a problem that the configuration of the monitoring device becomes complicated and it is difficult to accurately grasp the operation abnormality of the circuit breaker.

Therefore, an object of the present invention is to provide a method for diagnosing an operation abnormality in a power switch, which can accurately grasp an 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 the power switch of the present invention, a measurement microphone is arranged around the power switch to measure the operating sound when the power switch is opened and closed. Measure with a microphone. Then, based on the graph showing the relationship between the measured sound pressure and time, a map showing the relationship between frequency and time is created by fast Fourier transform, and based on the number of peaks appearing on the map or the position of the peaks. This is for determining the operation abnormality of the power switch.

Therefore, a simple operation may be performed in which the operating sound when the power switch is opened and closed is measured with a measuring microphone, and a map showing the time change of the frequency is created from the time change of the obtained sound pressure. Then, the operation abnormality of the power switch can be easily and accurately determined from the number of peaks appearing on the map or the position of the peak.

According to the method for diagnosing an operation abnormality in the power switch of the present invention, it is possible to accurately grasp the operation abnormality of the power switch with a simple configuration.

In the embodiment of the present invention, it is a map showing the relationship between frequency and time at the time of abnormal operation of the circuit breaker, (a) is a map showing an abnormal off operation, and (b) is an on-operation abnormality in which only the trigger operates. The map shown, (c) is a map showing an on-operation abnormality in which the link operates but the latch does not engage. It is a map showing the relationship between the frequency and time in the normal operation of the circuit breaker, (a) is a map showing the off operation, and (b) is the map showing the on operation. The schematic explanatory view which shows the positional relationship between a circuit breaker and a measuring microphone. It is explanatory drawing which shows the operation process of a circuit breaker, (a) is the explanatory view which shows the operation process at the time of an off operation, (b) is the explanatory view which shows the operation process at the time of an on-operation. (A) is a schematic perspective view showing a state in which the circuit breaker cover is removed, (b) is a schematic perspective view showing a state in which the circuit breaker cover is attached, and (c) is a schematic perspective view showing a state in which the circuit breaker cover is attached, and further protects the circuit breaker. The schematic perspective view which shows the state which covered the cover. (A) is a map under normal conditions with the circuit breaker cover removed, (b) is a map under normal conditions with the circuit breaker cover attached, (c) is a map with the circuit breaker cover attached, and further. A map under normal conditions with a protective cover on it. (A) is a map at the time of abnormal off operation with the circuit breaker cover removed, (b) is a map at the time of abnormal off operation with the circuit breaker cover attached, and (c) is covered with the circuit breaker. A map of when there is an abnormal cutting operation with a protective cover attached to it. A characteristic diagram showing the relationship between the sound pressure level and time when the circuit breaker is normal and when the circuit breaker is abnormally turned off. A characteristic diagram showing the relationship between the sound pressure level and time when the circuit breaker is normal and when two on-operation abnormalities occur. (A) is a characteristic diagram showing the relationship between the sound pressure level and time when the sound pressure level and time are removed when the measurement microphone is in a close position in a static environment with little reverberation, and (b) is a static environment and the measurement microphone is A characteristic diagram showing the relationship between the sound pressure level and time when the breaker cover is removed at a distant position, (c) shows the sound pressure level and time when the breaker is covered at a near position in a static environment. (D) is a characteristic diagram showing the relationship between the sound pressure level and time when the breaker is attached to the breaker in a static environment, and (e) is a characteristic diagram showing the relationship between the sound pressure level and time. A characteristic diagram showing the relationship between sound pressure level and time when a cover is attached to the vessel and a protective cover is attached to the vessel. A characteristic diagram showing the relationship between the sound pressure level and time in the case. (A) is a characteristic diagram showing the relationship between sound pressure level and time when the sound pressure level is removed at a near position in a reverberant environment with a lot of reverberation, and (b) is a characteristic diagram showing the relationship between the sound pressure level and time in a near position. A characteristic diagram showing the relationship between the sound pressure level and time when the sound pressure level is removed, (c) is a characteristic diagram showing the relationship between the sound pressure level and time when the cover is attached to the breaker at a close position, and the sound environment. d) is a characteristic diagram showing the relationship between the sound pressure level and time in the sound environment and when the breaker is covered at a distant position.

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 that has been used for 30 years is used. In this circuit breaker, an electric motor is provided in the circuit breaker main body, and a spring for accumulating power by starting the electric motor is provided. Further, the circuit breaker main body is provided with a link connected to the spring in conjunction with the main circuit, and in the off operation, the circuit breaker is stopped at the breaker completion position. In addition, the link engages with the latch at the closing position in the closing operation to maintain 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) causes the spring release 12 and the link operation 13 to be performed. It is stopped by the stopper 14 and the main circuit is turned off. On the other hand, as shown in FIG. 4B, when the main circuit of the circuit breaker is turned on, the main circuit is engaged with the latch by the trigger operation 16 such as a command signal through the spring release 17 and the link operation 18. Is turned on. After the off operation 15 and the on operation 20 of the main circuit, the opened spring is stored by the motor.

When the main circuit is turned off at 15:00, an operation noise is generated when the spring is released 12, the link operation is 13 and the stopper is stopped 14, and when the main circuit is turned on, the spring is released 17, the link operation 18 and the latch engagement 19 are performed. An operating noise is generated at such times. These operating sounds are continuously generated within a short period of time.

As shown in FIG. 3, in order to measure this operating noise, a position separated forward from the circuit breaker 21, for example, a position where the short distance D from the circuit breaker 21 is 5 cm and 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., which has excellent frequency characteristics, is used. The operating sound of the circuit breaker 21 can be measured by the measuring microphone 22 and the characteristics of the operating sound can be analyzed.

Next, a method of diagnosing an operation abnormality in the circuit breaker 21 will be described.
In this method of diagnosing an operation abnormality, first, a 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 conventional method of Fast Fourier Transform (FFT) based on the graph showing the relationship between the measured sound pressure (Pa) and time (s) ( Color map) is created. That is, the time change of the sound pressure characteristic is converted into the time change of the frequency characteristic according to the conventional method of FFT. This map is created by software that edits and analyzes time-series data of sound pressure by a conventional method, for example, analysis software Oscope2 of Ono Sokki Co., Ltd. Then, the operation abnormality 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 represented by the alternate long and short dash line in the map showing the relationship between frequency and time. Further, as shown in FIG. 2 (b), in the normal state, when the circuit breaker 21 is turned on, one peak 23 appears as represented by the alternate long and short dash line in the map, and the peak 23 starts 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, and the closer to 105 or 110, the more red, and the closer to 25 or 40, the black. Since the map is a color map, the number and position of peaks 23 can be easily visually recognized. The color maps of FIGS. 2 (a) and 2 (b) are attached to the property submission form.

On the other hand, as shown in FIG. 1A, when the circuit breaker 21 is abnormally turned off, two peaks 24 appear as represented by the alternate long and short dash line in the map. Therefore, it is possible to determine the off-operation abnormality based on the number of peaks 24 appearing in the map.

Further, as shown in FIG. 1 (b), among the on-operation abnormalities of the circuit breaker 21, when the on-operation abnormality in which only the trigger operates, the position of the peak 24 is from 25 ms as represented by the alternate long and short dash line in the map. Located in front. Further, as shown in FIG. 1 (c), among the on-operation abnormalities of the circuit breaker 21, the position of the peak 24 is represented by the two-dot chain line in the map when the on-operation abnormality in which the latch is not engaged after the link operation. Is located after 100 ms. Therefore, the input operation abnormality can be determined from the position of the peak 24 appearing in the map.

Since the maps of FIGS. 1 (a) to 1 (c) are color maps, the number and positions of the peaks 24 can be easily visually recognized. The color maps of FIGS. 1 (a) to 1 (c) are attached to the property submission form.

Next, when the cover of the circuit breaker 21 is removed as shown in FIG. 5 (a) (inspection state) A, when the circuit breaker 21 is covered with the cover 25 as shown in FIG. 5 (b) B and FIG. As shown in (c), when the circuit breaker 21 was covered with the cover 25 and housed in the protection box 26 (normal operation state) C, the off-operation abnormality of the circuit breaker 21 was examined.

In the case of A shown in FIG. 6 (a), in the case of B shown in FIG. 6 (b) and in the case of C shown in FIG. 6 (c), when the circuit breaker 21 is normal, the peak 23 in the map is in any case. Also appears one. On the other hand, in the case of A shown in FIG. 7 (a), in the case of B shown in FIG. 7 (b) and in the case of C shown in FIG. Appears in both cases.

In this way, regardless of the presence or absence of the cover 25 of the circuit breaker 21 and the protection box 26, it is possible to easily determine the off-operation abnormality of the circuit breaker 21 based on the number of peaks by using the above-mentioned map.

When it is determined that the breaker 21 has an off-operation abnormality or an on-operation abnormality as described above, the sound is narrowed down to a specific frequency, for example, a frequency in the 13 to 15 kHz band, and the sound is produced by the conventional method of the fast Fourier transform (FFT). A characteristic diagram showing the relationship between the pressure level (dB) and the time (ms) is created. This characteristic diagram converts the time change of the sound pressure characteristic into the time change of the sound pressure level characteristic according to the conventional method of FFT. This conversion is performed, for example, by the analysis software of Ono Sokki Co., Ltd. The specific frequency is a frequency band different from the resonance frequency around 11.5 kHz peculiar to metal as the natural vibration frequency of the breaker 21 and the frequency of local vibration sound (noise) of 19 kHz or more, that is, measurement of operating sound. It is a frequency band suitable for accurate operation.

The solid line shown in FIG. 8 is a waveform of the circuit breaker 21 in the normal state for the off operation, 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 off-operation abnormality of the circuit breaker 21, two peaks 28 having a sound pressure level of 85 dB or more appear, and the sound pressure level after 200 ms is 150% or more of the normal state. Is. Therefore, by setting an appropriate threshold value for the sound pressure level at the normal time, it is possible to accurately determine the off-operation abnormality of the circuit breaker 21. In addition, the operation sound was measured twice at the time of normal operation and at the time of abnormal off operation.

Further, as shown by the solid line in FIG. 9, the waveform of the circuit breaker 21 in the normal state is shown, 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 on-operation abnormality in which only the trigger of the circuit breaker 21 operates, the waveform 29 has no peak with a sound pressure level of 85 dB or more, and the sound pressure level after 200 ms is high. It is 10% or less of the normal state.

Further, as shown by the broken line in FIG. 9, in the case of an on-operation abnormality in which the latch is not engaged 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 the normal state. Therefore, by setting an appropriate threshold value for the sound pressure level at the normal time, it is possible to accurately determine the on-operation abnormality of the circuit breaker 21. In addition, the operation sound was measured twice at the time of normal operation and at the time of abnormal on operation.

In this way, the off-operation abnormality or the on-operation abnormality of the circuit breaker 21 is clearly determined based on the number of peaks or the threshold value of the sound pressure level by using the characteristic diagram showing the relationship between the sound pressure level and the time. Can be done.

Next, regarding the measurement environment of the operating sound, in an environment with little reverberation (static environment) and an environment with a lot of reverberation (reverberation environment), the measurement microphone 22 is at a position (near position) where the short distance D from the circuit breaker 21 is 5 cm. At a position (far position) where the long separation distance L is 50 cm, the cases where the circuit breaker 21 is A, B, and C are examined.

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

In FIGS. 10 (a) to 10 (f) and 11 (a) to 11 (d), the solid line represents the waveform 30 in the normal state, and the broken line represents the waveform 31 in the off-operation abnormality. It should be noted that both the waveform 30 and the waveform 31 are the results of measuring the operating sound twice.

By comparing these FIGS. 10 (a) to 10 (f) with FIGS. 11 (a) to 11 (d), it was shown that the sounding environment tends to determine the operation abnormality of the circuit breaker 21 more easily than the static environment. Further, a comparison between FIGS. 10 (a) and 10 (b), a comparison between FIGS. 10 (c) and 10 (d), a comparison between FIGS. 10 (e) and 10 (f), and FIG. 11 ( Based on the comparison between a) and FIG. 11 (b) and the comparison between FIGS. 11 (c) and 11 (d), the position of the measurement microphone 22 is abnormal when the circuit breaker 21 is located farther than near. It showed a tendency to be easy to distinguish.

Subsequently, a specific procedure for diagnosing the operation abnormality of the circuit breaker 21 will be described.
1) The operating sound of the circuit breaker 21 in the normal state is measured, and the initial pattern is retained.
2) With respect to the circuit breaker 21 that has been used for a long time, the operating sound of the circuit breaker 21 in the energized state is measured by 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 discriminated by comparing with the initial pattern and collating the abnormal pattern based on the map.
4) If it is determined that there is an operation abnormality in 3) above, the aspect of the operation abnormality is compared with the threshold value based on the characteristic diagram showing the relationship between the sound pressure level and the time by narrowing down to a specific frequency. to decide.

5) The circuit breaker 21 determined to have an operation abnormality is inspected and maintained after a power failure.
Next, the operation of the method of diagnosing the operation abnormality in the circuit breaker 21 of the present embodiment will be described.
When diagnosing an operation abnormality of the circuit breaker 21, a measurement microphone 22 is arranged around the circuit breaker 21 to measure an operation sound emitted when the circuit breaker 21 is opened and closed. Then, based on the graph showing the relationship between the measured sound pressure and time, a map showing the relationship between frequency and time is created by FFT. From the obtained map, the operation abnormality of the circuit breaker 21 can be qualitatively determined based on the number of peaks appearing on the map or the position of the peak. Since this map is a color map, the number and position of peaks can be recognized quickly visually.

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

The effects exhibited by the above embodiments are summarized below.
(1) In the method of diagnosing an operation abnormality in the circuit breaker 21 of this embodiment, a 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 graph showing the time change of the obtained sound pressure characteristic. Then, the operation abnormality of the circuit breaker 21 can be determined based on the number of peaks appearing on the map or the position of the peak.

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

Therefore, according to the diagnostic method of the embodiment, it is possible to accurately grasp the operation abnormality of the circuit breaker 21 with a simple configuration.
(2) The power switch has a spring release 12 by a trigger operation 11, a stop 14 by a stopper by a link operation 13, and a main circuit off operation 15, while a spring release 17 by a trigger operation 16 and a latch by a link operation 18. It is a spring-operated circuit breaker 21 that engages 19 and the main circuit enters and operates 20. By measuring the operating noise during the off operation and the on operation of the circuit breaker 21, it is possible to easily determine the off operation abnormality and the on operation abnormality of the circuit breaker 21.

(3) The measurement microphone 22 is arranged at a position separated from the circuit breaker 21. In this case, the operating sound of the circuit breaker 21 can be accurately measured by the measuring microphone 22 while avoiding noise such as the vibration sound of the circuit breaker 21. Further, in the normal operation state, it is possible to determine the operation abnormality of the circuit breaker 21 without disturbing the operation of the circuit breaker 21.

(4) If there are two peaks appearing on the map, it is determined that the off operation is abnormal, and if the peak is located before 25 ms, it is determined that only the trigger operation is performed. If the peak is located after 100 ms, it is determined that the latch engagement is not performed after the link operation and the input operation is abnormal. Therefore, the operation abnormality of the circuit breaker 21 can be easily determined based on the number of peaks appearing on the map or the position of the peak.

(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 based on the sound pressure level based on the number of peaks in the characteristic diagram and the threshold value set with reference to the normal time. Determine the operation abnormality. Therefore, by creating a characteristic diagram of the sound pressure level and time, it is possible to accurately determine the operation abnormality 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 operating sound in a frequency band different from the resonance frequency peculiar to metal as the natural vibration frequency of the breaker 21 and the frequency of the local vibration sound. Specifically, the frequency band is a frequency band of 13 to 15 kHz. Therefore, the reliability of the characteristic diagram can be improved without being disturbed by the natural vibration frequency or the noise frequency of the circuit breaker 21.

It is also possible to modify the embodiment as follows to embody it.
-If the operation abnormality of the circuit breaker 21 can be accurately determined using the map, the creation of the characteristic diagram showing the relationship between the sound pressure level and the time may be omitted.

The measurement microphone 22 may be arranged 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 flood control or air may be used.

-As the power switch, a switch such as a switch, a disconnector, or the like may be used.

11 ... Trigger operation, 12 ... Spring release, 13 ... Link operation, 14 ... Stop at stopper, 15 ... Main circuit off operation, 16 ... Trigger operation, 17 ... Spring release, 18 ... Link operation, 19 ... Latch engagement, 20 ... Main circuit is on, 21 ... Circuit breaker, 22 ... Measurement microphone.

Claims (7)

A measurement microphone is placed around the power switch, the operating sound when the power switch is opened and closed is measured by the measurement microphone, and high-speed Fourier is based on a graph showing the relationship between the measured sound pressure and time. A method of diagnosing an operation abnormality in a power switch by creating a map showing the relationship between frequency and time by conversion and determining an operation abnormality of the power switch based on the number of peaks appearing on the map or the position of the peak. .. 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 latch engages by the link operation to turn on the main circuit. The method for diagnosing an operation abnormality in a power switch according to claim 1, which is a spring-operated circuit breaker. The method for diagnosing an operation abnormality in a power switch according to claim 1 or 2, wherein the measurement microphone is arranged at a position separated from the power switch. If there are two peaks appearing on the map, it is judged to be an off-operation abnormality, and if the peak is located before 25 ms, it is determined to be an on-operation abnormality in which only the trigger operation is performed, and the peak is determined. The method for diagnosing an operation abnormality in a power switch according to claim 2 or 3, wherein when is located after 100 ms, it is determined that the latch engagement is not performed 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 sound pressure level based on the number of peaks in the characteristic diagram and the threshold value set based on the normal time is used to determine the power switch. The method for diagnosing an operation abnormality in a power switch according to claim 1, wherein the operation abnormality is determined. The characteristic diagram according to claim 5, wherein the characteristic diagram is created based on an operating sound in a frequency band different from the resonance frequency peculiar to metal as the natural vibration frequency of the power switch and the frequency of the local vibration sound. How to diagnose malfunctions in 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.

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