JPH0560138U - Abnormal vibration monitoring device for electrical equipment - Google Patents

Abstract

(57) [Summary] [Purpose] Abnormal vibration generated in the container of electrical equipment is detected with high sensitivity and reliability. [Structure] A vibration sensor 14 is attached to the wall surface of a container of an electric device 10, and the output of the vibration sensor 14 is passed through an amplifier 15 to
It is given to the / D converter 16. The digital signal obtained from the A / D converter 16 is given to the frequency analysis means 17 and subjected to Fourier transform, and the frequency spectrum data of the vibration waveform detected by the vibration sensor is given to the arithmetic unit 18. Arithmetic unit 18
Determines the presence or absence of abnormal vibration based on the given frequency spectrum data.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an abnormal vibration monitoring device for monitoring abnormal vibration generated inside a container of electric equipment such as a gas insulated switchgear.

[0002]

[Prior Art]

 If metal foreign matter such as metal chips or burrs is present in the gas insulated switchgear, partial discharge may occur from the tip of the foreign matter, and partial discharge may occur even if there is poor contact at the conductor contact area. May occur. If a partial discharge that occurs inside the gas insulated switchgear is left unattended, dielectric breakdown may occur eventually resulting in a serious accident.

Therefore, in order to prevent an accident in an electric device, it is necessary to monitor whether or not there is a metallic foreign substance inside the device, and also to monitor the occurrence of partial discharge.

Therefore, vibration generated when a metallic foreign object moves inside the container of an electric device such as a gas insulated switchgear and the foreign object collides with the inner surface of the container, or vibration caused by partial discharge is regarded as an abnormal vibration. An abnormal vibration monitoring device that monitors the presence or absence of these abnormal vibrations has been proposed.

FIG. 4 shows a conventionally used abnormal vibration monitoring device. In FIG. 4, 1 is a gas-insulated switchgear, 2 is a vibration sensor mounted on the wall surface of a container of the gas-insulated switchgear, and 3 is a vibration sensor. Is an amplifier that amplifies the output of the vibration sensor 2, 4 is a filter that removes noise from the output of the amplifier 3, and 5 is an analog-digital converter (A / A / D) that converts the noise-removed signal into a digital signal. D converter), 6 is a microcomputer for processing the digital signal obtained from the A / D converter 5 to identify abnormal vibration.

In the apparatus shown in FIG. 4, the vibration sensor 2 detects the vibration generated in the gas-insulated switchgear 1. After the output of the sensor 2 is amplified by the amplifier 3, it is input to the filter 4, and the low-frequency vibration generated during the steady state of the gas insulated switchgear is removed from the output of the sensor as noise. Next, the output of the filter 4 is converted into a digital signal by the A / D converter 5, and this digital signal is input to the microcomputer 6 for averaging and addition processing, whereby external noise and abnormal vibration are discriminated and discriminated. The abnormal vibration is detected from the level of abnormal signal, frequency of occurrence and continuity.

[0007]

[Problems to be solved by the device]

 In the above-mentioned conventional abnormal vibration monitoring apparatus, the natural vibration of the equipment other than the abnormal vibration is removed as noise by the filter 4, but when the frequency range of the noise is close to that of the abnormal vibration, it is removed. There was a problem that it was difficult to do.

Further, in the above-mentioned conventional apparatus, in order to prevent the abnormal vibration due to the partial discharge showing the periodic repetition from being mistaken for the periodic noise, the averaging addition processing is performed using the microcomputer to perform the level determination. However, since it relies on the high-frequency vibration wave level determination, there is a strong possibility that an erroneous determination will occur if high-level high-frequency noise continues to occur. There is also a problem that detection becomes difficult in the case of weak abnormal vibration.

An object of the present invention is to provide an abnormal vibration monitoring apparatus for electric equipment, which has an improved detection function and an improved detection sensitivity.

[0010]

[Means for Solving the Problems]

 In the present invention, a vibration sensor attached to an electric device to detect vibration of the electric device, an analog-digital converter for converting vibration wave data given in time series from the vibration sensor into a digital signal, and the analog A frequency analysis means for determining the frequency spectrum of the vibration wave data using the output of the digital converter as an input, and an abnormal vibration determination means for determining the presence or absence of abnormal vibration from the frequency spectrum obtained by the frequency analysis means are provided.

The abnormal vibration judging means may judge the presence or absence of abnormal vibration from the pattern of the frequency spectrum characteristic of the detected vibration wave, or integrate each frequency component of the frequency spectrum in a specific frequency band. Then, the presence or absence of abnormal vibration may be determined by comparing the integrated value with a predetermined identification level.

[0012]

[Action]

 In the above-described configuration, the vibration sensor detects, as noise, not only the abnormal vibration that is the target, but also a vibration peculiar to the electric device during the normal operation and an external vibration. Vibration wave data obtained in time series from the vibration sensor is input to an analog-digital converter and converted into a digital signal. This digital signal is input to the frequency analysis means and Fourier-transformed, whereby the frequency spectrum of the output signal of the vibration sensor is obtained. Generally, steady vibrations generated by electrical equipment exist in the low frequency range, while abnormal vibrations exist in the relatively high frequency range. Therefore, by identifying the pattern of the frequency spectrum obtained by the frequency analysis means, or by integrating each frequency component of the frequency spectrum of the predetermined frequency band and comparing the integrated value with the predetermined discrimination level, The presence or absence of vibration can be determined.

When the presence or absence of abnormal vibration is determined based on the frequency spectrum of the vibration wave data as described above, as long as the abnormal vibration exists, the vibration cannot be weak even if it is in a predetermined frequency band. Since a peak appears at, the abnormal vibration can be distinguished from other vibrations to improve the detection sensitivity.

[0014]

【Example】

 FIG. 1 shows an embodiment of the present invention. In FIG. 1, reference numeral 10 denotes a gas-insulated switchgear, and in this example, a tubular member connected through an insulating spacer 11 in the gas-insulated switchgear. The configuration of the bus bar portion in which the main circuit conductor 13 is housed in the metal containers 12a, 12b, 12c is schematically illustrated.

The abnormal vibration monitoring apparatus according to the present invention includes a vibration sensor 14 mounted on a wall surface of a container 12b of a gas insulated switchgear (electrical device), an amplifier 15, and an analog-digital converter (A / D converter). ) 16, a frequency analysis means 17 composed of a digital signal processing unit (DSP), and an arithmetic unit 18 composed of a microcomputer.

Note that the DSP is composed of a board on which a dedicated CPU is mounted and performs frequency analysis according to a predetermined program. When a personal computer is used as the arithmetic unit 18, a DSP board can be mounted inside the personal computer. When frequency analysis is performed using a dedicated digital signal processing unit, the processing speed can be increased and multi-channel processing becomes possible.

In the present invention, the Fourier analysis by the microcomputer is not hindered. Further, a spectrum analyzer or the like can be used instead of the DSP.

The vibration sensor 14 is composed of an acceleration sensor, and detects the acceleration of vibration generated inside the container 12b. The vibration wave data obtained in time series from this vibration sensor is amplified by the amplifier 15 and given to the A / D converter 16, which converts it into a digital signal. This digital signal is input to the frequency analysis means 17 which is composed of a digital signal processing unit. The frequency analysis means 17 processes the digitized vibration wave data and performs a Fourier transform to obtain each frequency component (frequency spectrum) included in the detected vibration wave data.

The frequency spectrum data obtained by the frequency analysis means 17 is given to the arithmetic unit 18. The arithmetic unit 18 obtains an integral value of the vibration acceleration in a predetermined frequency band and compares the spectrum characteristic pattern obtained by the frequency analysis means with the spectrum characteristic pattern of each abnormal vibration obtained in advance by an experiment. Then, the presence or absence of abnormal vibration is identified. In this embodiment, the arithmetic unit 18 constitutes abnormal vibration determination means for determining the presence or absence of abnormal vibration.

The waveform of the vibration wave data obtained when the vibration (steady vibration) generated in the gas insulated switchgear at a steady state (steady vibration) is detected is as shown in FIG. 2 (A), for example. The frequency spectrum pattern of the vibration wave data of this steady vibration is, for example, as shown in FIG. 2B, and has a peak at a relatively low frequency fo.

On the other hand, the abnormal vibration caused by the movement of the metallic foreign matter existing in the container of the gas insulated switchgear in the container shows a spectrum characteristic having a peak in a frequency band higher than the steady vibration. The abnormal vibration caused by partial discharge has a spectrum characteristic with a peak in a higher frequency band than the vibration caused by foreign matter.

The vibration wave data when abnormal vibration is caused by foreign matter is as shown in FIG. 3 (A), for example, and the spectrum characteristic pattern obtained by frequency analysis of this vibration wave data is shown in FIG. 3 (B). As described above, the pattern also has a peak at the frequency f1 in the frequency band higher than the frequency component included in the steady vibration. The presence or absence of abnormal vibration can be determined by identifying the patterns of these spectrum characteristics.

As described above, when the abnormal vibration exists, a peak appears in a specific frequency band depending on the cause of the abnormal vibration. Therefore, by identifying the pattern of the frequency spectrum characteristic of the vibration wave data, the abnormal vibration is detected. You can know whether or not.

Further, since it is possible to know in advance which frequency band the peak appears in according to the content of the abnormality, it is necessary to provide an integrator in the frequency analysis means 17 or to make the arithmetic unit 18 perform an integral operation. Thus, it is possible to integrate each frequency component of the spectrum of a specific frequency band and use the integrated value for the determination of the presence or absence of abnormal vibration. For example, in the example shown in FIG. 3B, when the components of each frequency are integrated over the frequency band before and after the frequency f1, the integrated value exceeds the predetermined discrimination level, so that abnormal vibration may exist. I understand.

When the frequency spectrum of the vibration wave is obtained as described above, if there is an abnormal vibration, a component always appears in a specific frequency band even if the vibration is weak, so that the abnormal vibration is The detection sensitivity can be enhanced by distinguishing it from vibration.

[0026]

[Effect of the device]

 As described above, according to the present invention, the presence or absence of abnormal vibration is determined based on the frequency spectrum of the vibration wave data obtained by the vibration sensor, so that abnormal vibration can be detected reliably and with high sensitivity. There is an advantage that can be.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of the present invention.

FIG. 2A is a waveform diagram showing an example of a vibration waveform detected by a vibration sensor in the present invention. (B) is a diagram showing a frequency spectrum of the vibration waveform of (A).

FIG. 3A is a waveform diagram showing another example of the vibration waveform detected by the vibration sensor in the present invention. (B)
FIG. 4 is a diagram showing a frequency spectrum of the vibration waveform of (A).

FIG. 4 is a block diagram showing a configuration of a conventional abnormal vibration monitoring device.

[Explanation of symbols]

10 ... Gas insulated switchgear (electric equipment), 14 ... Vibration sensor, 15 ... Amplifier, 16 ... Analog-digital converter, 1
7 ... Frequency analysis means, 18 ... Computing device (abnormal vibration determination means).

Claims (1)

[Scope of utility model registration request] 1. A vibration sensor attached to an electric device to detect vibration of the electric device; an analog-digital converter for converting vibration wave data given in time series from the vibration sensor into a digital signal; and the analog. A frequency analysis means for obtaining the frequency spectrum of the vibration wave data by using the output of the digital converter as input, and an abnormal vibration determination means for determining the presence or absence of abnormal vibration from the frequency spectrum obtained by the frequency analysis means are provided. An abnormal vibration monitoring device for electric equipment.