JP2541739B2 - Partial discharge detection method for electric equipment and partial discharge detection device for electric equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a partial discharge detection method for detecting a partial discharge generated in an electric device. The main object of the present invention is a distribution line pole device. It is intended.

[0002]

2. Description of the Related Art In electric power equipment, abnormality of the equipment is known by detecting partial discharge generated in the equipment.

As a method of detecting a partial discharge generated in an electric device, a method of detecting an electromagnetic wave generated by the partial discharge is known. In this method, it is necessary to distinguish between the signal generated by the partial discharge and the noise. Generally, electromagnetic waves generated by partial discharge are extremely weak, so T
When artificial radio waves used for V, radio, wireless communication, etc. come in and enter the detection circuit, external radio waves and electromagnetic waves due to partial discharge cannot be distinguished and received. Will fail.

Therefore, one of the applicants of the present application (Nisshin Electric Co., Ltd.) has disclosed in JP-A-63-145974 a partial discharge by using an empty channel for television broadcasting radio waves in which no artificial radio waves exist. We have applied for a method to detect electromagnetic waves generated by.

[0005]

A method of detecting an electromagnetic wave due to a partial discharge by receiving an empty channel of a radio wave for television broadcasting as described above ensures the electromagnetic wave due to a partial discharge without being affected by an external radio wave. It has the advantage of being detectable.

In the case of detecting an extremely weak electromagnetic wave due to a partial discharge in an electric device, the above-mentioned method of receiving an empty channel of a radio wave for television broadcasting has a problem. The band is very wide, but the band to be detected is a narrow band called an empty channel for television broadcast radio waves. That is, the pattern of the frequency spectrum of the electromagnetic wave generated differs depending on the state of the partial discharge, and therefore there is a possibility that the electromagnetic wave due to the partial discharge may be missed due to misalignment. Moreover, since only a part of the energy of the electromagnetic waves due to the partial discharge is detected, the S / N ratio cannot be sufficiently increased.

In particular, in the pole equipment of the distribution line, such as pole transformers, pole switches, or insulating supports for electric wires such as insulators,
Just because a partial discharge has occurred is not considered a failure,
Naturally, the protective device does not operate, but the partial discharge (corona discharge) is a precursor phenomenon such as insulation deterioration, and the detection of the partial discharge is important for maintenance and inspection of the distribution line. However, the locations of the overhead power distribution lines are extremely diverse, and the pattern of external electromagnetic waves (spectrum, etc.) changes depending on the region, place or time zone. Therefore, how to set the reference to detect an abnormal partial discharge becomes a problem.

An object of the present invention is to detect the energy of an electromagnetic wave over a wide band due to a partial discharge, and to reliably detect even a weaker partial discharge or a partial discharge which produces an electromagnetic wave having a different frequency spectrum. An object of the present invention is to provide a method of detecting partial discharge of an electric device that can be performed.

[0009]

SUMMARY OF THE INVENTION In view of the fact that the frequency spectrum of an electromagnetic wave generated by a partial discharge generated in an electric device extends over a wide band, the present invention basically provides a method for detecting the presence or absence of partial discharge on the frequency spectrum. Invented

FIG. 8 shows the frequency spectrum of the electromagnetic wave detected in the place where the conditions are different. These spectra are background noise (BGN) for electromagnetic waves due to the partial discharge that is the detection target. In order to detect the electromagnetic waves due to the partial discharge, it is sufficient to detect how much the level at each frequency rises from this background noise. However, it is difficult to say that the spectrum when the partial discharge is experimentally generated and the spectrum of the background noise can be easily discriminated as shown in FIG. The partial discharge shown here is generated by applying a voltage by providing a partial discharge power source of 10000 pC inside the pole transformer. In addition, BGN is a spectrum when sound is not generated at the same point.

Therefore, it is conceivable to subtract the background noise spectrum from the measured frequency spectrum for observation. An example thereof is shown in FIG. 10, but even in this case, the case where the partial discharge amount is considerably large can be clearly read visually, and the small partial discharge cannot reliably read.

Therefore, the method for detecting partial discharge of an electric device according to claim 1 of the present invention detects the partial discharge of the electric device by detecting an electromagnetic wave generated by the partial discharge generated in the electric device. In this method, the frequency spectrum is calculated for each of the detected electromagnetic wave and the reference electromagnetic wave, the component of the band of the broadcast wave and / or the communication wave is removed from the frequency spectrum to obtain the correction spectrum, and the correction spectrum is set to a constant frequency range. To obtain a cumulative integrated spectrum and compare the cumulative integrated spectrums of the detected electromagnetic wave and the reference electromagnetic wave to detect the partial discharge occurrence status.

According to a second aspect of the present invention, there is provided a partial discharge detection device for an electric device, wherein the partial discharge detection device for an electric device detects the partial discharge by detecting an electromagnetic wave generated by the partial discharge generated in the electric device. Frequency spectrum analyzing means for obtaining a frequency spectrum for each of the detected electromagnetic wave and the reference electromagnetic wave, and a corrected spectrum generating means for removing a component of a band of a broadcast wave and / or a communication wave from the obtained frequency spectrum to obtain a corrected spectrum, And a spectrum cumulative integration means for calculating the cumulative integrated spectrum by integrating the corrected spectrum in a constant frequency range.

According to a third aspect of the present invention, there is provided a partial discharge detection device for an electric device, wherein the partial discharge detection device for an electric device detects the partial discharge by detecting an electromagnetic wave generated by the partial discharge generated in the electric device. Frequency spectrum analysis means for obtaining a frequency spectrum of each of the electromagnetic wave and the reference electromagnetic wave; a corrected spectrum generation means for removing a component of the band of the broadcast wave and / or the communication wave from the obtained frequency spectrum to obtain a corrected spectrum; From difference spectrum generating means for obtaining a difference component of the correction spectrum for the detected electromagnetic wave with respect to the correction spectrum for the electromagnetic wave, and spectrum cumulative integration means for respectively integrating the difference spectrum in a constant frequency range to obtain a cumulative integral spectrum. Na .

According to a fourth aspect of the present invention, there is provided a partial discharge detection device for an electric device, wherein the partial discharge detection device for an electric device detects the partial discharge by detecting an electromagnetic wave generated by the partial discharge generated in the electric device. Frequency spectrum analysis means for obtaining a frequency spectrum of each of the electromagnetic wave and the reference electromagnetic wave; a corrected spectrum generation means for removing a component of the band of the broadcast wave and / or the communication wave from the obtained frequency spectrum to obtain a corrected spectrum; Difference spectrum generating means for obtaining a difference component of the correction spectrum for the detected electromagnetic wave with respect to the correction spectrum for the electromagnetic wave, integration means for obtaining an integral value of the difference spectrum in a constant frequency range, and the integration with respect to a predetermined reference value. Part by comparing the magnitude of the value Judging means for judging whether the discharge consists city.

According to a fifth aspect of the present invention, there is provided a partial discharge detection device for an electric device, wherein the partial discharge detection device for an electric device detects the partial discharge by detecting an electromagnetic wave generated by the partial discharge generated in the electric device. Frequency spectrum analysis means for obtaining a frequency spectrum of each of the electromagnetic wave and the reference electromagnetic wave; a corrected spectrum generation means for removing a component of the band of the broadcast wave and / or the communication wave from the obtained frequency spectrum to obtain a corrected spectrum; Difference spectrum generation means for obtaining a difference component of the correction spectrum for the detected electromagnetic wave with respect to the correction spectrum for the electromagnetic wave, and spectrum cumulative integration means for calculating the cumulative integral spectrum by integrating the difference spectrum in a constant frequency range,
The determination means determines the presence or absence of partial discharge by comparing the magnitude of the slope of the cumulative integrated spectrum with respect to a predetermined reference value.

According to a sixth aspect of the present invention, there is provided a method for detecting a partial discharge of an electric device according to the first aspect, wherein the partial discharge detection target device is a distribution line pole device, and the pole device for detecting the detected electromagnetic wave is mounted. And the reference electromagnetic wave is an external electromagnetic wave under another distribution line pillar adjacent to the distribution line pillar.

According to a seventh aspect of the present invention, there is provided a partial discharge detection device for an electric device according to any one of the second to fifth aspects, wherein the partial discharge detection target device is a distribution line pole device and the detected electromagnetic wave is detected. An external electromagnetic wave under a distribution line pillar on which a pole device to be mounted is installed and the reference electromagnetic wave is an external electromagnetic wave under another distribution line pillar adjacent to the distribution line pillar.

[0019]

In the partial discharge detection method for electric equipment according to the first aspect of the present invention, the frequency spectrums of the electromagnetic waves of the detected electromagnetic wave and the reference electromagnetic wave are respectively obtained, and the bands of the broadcast wave and the communication wave are calculated from the obtained spectra. The corrected spectrum with the component of is removed is obtained. And
The corrected spectrum is integrated over a fixed frequency range to obtain a cumulative integrated spectrum. The state of occurrence of partial discharge is detected by comparing the cumulative integrated spectra of the detected electromagnetic wave and the reference electromagnetic wave thus obtained. The frequency spectrum of the reference electromagnetic wave is obtained in a state where it is known in advance that partial discharge has not occurred, or is close to the position to be detected, for example, when a device on a distribution line pole is targeted, it is adjacent to the distribution line pole. What was measured under below may be used. In this way, by removing the components of the broadcast wave and communication wave bands from the frequency spectrum of the electromagnetic waves to be detected,
It is possible to eliminate the influence of broadcast waves and communication waves,
Moreover, since the cumulative integrated spectrum is compared, the presence or absence of partial discharge can be easily grasped as compared with the case where the frequency spectrum is directly subjected to pattern comparison.

In the partial discharge detecting device for electric equipment according to the second aspect of the present invention, the frequency spectrum analyzing means obtains the frequency spectrums of the electromagnetic waves of the detected electromagnetic wave and the reference electromagnetic wave, respectively, and the correction spectrum generating means obtains them. The corrected spectrum is obtained by removing the components of the bands of the broadcast wave and the communication wave from the spectrum. Then, the spectrum cumulative integration means integrates the corrected spectrum in a constant frequency range to obtain a cumulative integration spectrum. It is possible to detect the occurrence state of partial discharge by comparing the cumulative integrated spectra of the detected electromagnetic wave and the reference electromagnetic wave obtained in this way.

In the partial discharge detecting device for electric equipment according to the third aspect, the frequency spectrum analyzing means obtains the frequency spectrums of the electromagnetic waves of the detected electromagnetic wave and the reference electromagnetic wave respectively, and the correction spectrum generating means uses the obtained spectrums. , Remove the components of the broadcast wave and communication wave bands to obtain the corrected spectrum. The difference spectrum generation means obtains the difference component of the correction spectrum of the detected electromagnetic wave with respect to the correction spectrum of the reference electromagnetic wave. And the spectrum cumulative integration means is
The difference spectrum is integrated over a fixed frequency range to obtain a cumulative integrated spectrum. It is possible to detect the occurrence state of partial discharge by comparing the cumulative integrated spectra of the detected electromagnetic wave and the reference electromagnetic wave obtained in this way. The reference spectrum is a frequency spectrum of detected electromagnetic waves (that is, background noise) in a state where electromagnetic waves due to partial discharge are not generated, so that background noise is removed, and a frequency spectrum of only electromagnetic waves due to partial discharge to be detected. Can be extracted. Furthermore, by integrating the difference spectrum thus obtained over a certain frequency range, it is possible to obtain the energy of the electromagnetic wave due to the partial discharge over a wide band, so that even the electromagnetic wave due to the extremely weak partial discharge can be reliably detected. Become.

In the partial discharge detection apparatus for electric equipment according to the fourth aspect, the frequency spectrum analysis means obtains the frequency spectrum of each electromagnetic wave of the detected electromagnetic wave and the reference electromagnetic wave, and the correction spectrum generation means uses the obtained spectrum. , Remove the components of the broadcast wave and communication wave bands to obtain the corrected spectrum. The difference spectrum generation means obtains the difference component of the correction spectrum of the detected electromagnetic wave with respect to the correction spectrum of the reference electromagnetic wave. The integrating means integrates the difference spectrum in a constant frequency range to obtain an integrated value. Further, the determination means determines the presence / absence of partial discharge by comparing the obtained integral value with a reference value. If partial discharge has occurred, the integrated value becomes larger than the reference value, and as a result, it can be determined that partial discharge has occurred.

As described above, by removing the components of the bands of the broadcast wave and the communication wave from the frequency spectrum of the electromagnetic wave to be detected, the influence of the broadcast wave and the communication wave can be removed, and the reference spectrum As detected electromagnetic waves (that is, background noise) in a state where electromagnetic waves due to partial discharge are not generated
With the frequency spectrum of, it is possible to extract the frequency spectrum of only the electromagnetic waves due to the partial discharge to be detected, in which the background noise is removed. Furthermore, by integrating the difference spectrum obtained in this way over a certain frequency range, the energy of the electromagnetic wave due to partial discharge over a wide band can be obtained as a single value, and even if the electromagnetic wave due to extremely weak partial discharge is the reference value. It is possible to obtain an integrated value that greatly differs from the value, and it becomes possible to reliably detect partial discharge.

In the partial discharge detecting device for electric equipment according to the fifth aspect, the frequency spectrum analyzing means obtains the frequency spectrums of the electromagnetic waves of the detected electromagnetic wave and the reference electromagnetic wave, respectively, and the correction spectrum generating means uses the obtained spectrums. , Remove the components of the broadcast wave and communication wave bands to obtain the corrected spectrum. The difference spectrum generation means obtains the difference component of the correction spectrum of the detected electromagnetic wave with respect to the correction spectrum of the reference electromagnetic wave. The spectrum cumulative integration means integrates the difference spectrum in a constant frequency range to obtain a cumulative integration spectrum. Further, the determination means determines the presence / absence of partial discharge by comparing the obtained integral value with a reference value. If partial discharge occurs, the slope of the cumulative integration spectrum becomes larger than that when no partial discharge occurs.Therefore, determine the presence or absence of partial discharge by setting the reference value in advance. it can.

As described above, by removing the components of the band of the broadcast wave and the communication wave from the frequency spectrum of the electromagnetic wave to be detected, the influence of the broadcast wave and the communication wave can be removed, and the reference spectrum As a result, by using the frequency spectrum of the background noise, it is possible to extract the frequency spectrum of only the electromagnetic waves due to the partial discharge to be detected, in which the background noise is removed. Furthermore, by cumulatively integrating the difference spectrum obtained in this way over a certain frequency range, the existence of electromagnetic waves due to partial discharge over a wide band can be obtained as the value of the slope of the cumulative integral spectrum, and electromagnetic waves due to extremely weak partial discharge can be obtained. Even if there is, it will be possible to detect it with certainty.

According to a sixth aspect of the present invention, there is provided a method of detecting a partial discharge of an electric device according to the first aspect, wherein a pole device on a distribution line is a target device for detecting a partial discharge, and a pole device for detecting a partial discharge is mounted. An external electromagnetic wave under a distribution line pillar is a detected electromagnetic wave, and an external electromagnetic wave under another distribution line pillar adjacent to the distribution line pillar is a reference electromagnetic wave.

Further, in the partial discharge detection device for an electric device according to claim 7, in any one of claims 2 to 5 , the device on the distribution line pole is a target device for detection of partial discharge,
The external electromagnetic wave under the distribution line pillar on which the pole equipment for which partial discharge should be detected is mounted is the detected electromagnetic wave, and the external electromagnetic wave under the other distribution line pillar adjacent to the distribution line pillar is the reference electromagnetic wave. To be done.

For example, in an overhead distribution line pillar installed along a road, a measurement vehicle is run along the road, and an external electromagnetic wave is detected as a detected electromagnetic wave or a reference electromagnetic wave every time the vehicle is stopped under each distribution line pillar. Measure and compare the external electromagnetic wave under another adjacent distribution line pillar as a reference electromagnetic wave. At that time, if it is in the same area at the same time, the electromagnetic waves coming from far away are commonly received in the whole area.
If the device on the pole of the distribution line above the measurement vehicle is partially discharged, it will receive an electromagnetic wave on which the electromagnetic waves emitted from it are superimposed. However, since one span (span length) of a distribution line column is generally several tens of meters, the partial discharge has almost no effect on the measurement under the adjacent distribution line column. As a result, it becomes possible to easily and surely detect the partial discharge of the pole equipment on the distribution line without being affected by the various variable elements, with the external electromagnetic wave including the region, place or time zone characteristic as a reference.

[0029]

1 to 3 show the structure of a partial discharge detecting apparatus to which the partial discharge detecting method for electric equipment of the present invention is applied.

FIG. 1 is a block diagram showing the configuration of the control unit. In FIG. 1, the spectrum analyzer 2 obtains the frequency spectrum of the signal induced in the antenna 1 as digital data of the level (dBm) at each frequency. The CPU 4 executes a program written in the memory 5 in advance, and performs control for detecting partial discharge according to a processing procedure described later. The memory 5 is a ROM in which a program to be executed by the CPU 4 is written in advance and a RAM used as a working area when the program is executed.
Consists of The CPU 4 reads the data of the frequency spectrum obtained by the spectrum analyzer 2 via the interface 3 and performs various calculation processes described later. The display unit 7 displays a cumulative integrated spectrum as a final processing result or a determination result of the presence or absence of partial discharge. The interface 6 has a display memory, and a CP
U4 writes the display data in the display memory of the interface 6 to display the predetermined content. The printer 9 prints out the processing result. The CPU 4 controls printing via the interface 8. The key switch 11 gives an instruction to start measurement and the like. The CPU 1 reads the key operation content via the interface 10 and performs processing according to the key operation.

FIG. 2 is a flow chart showing the processing procedure of the CPU 4 shown in FIG. First, the spectrum data is read from the spectrum analyzer 2 and the level at each frequency is converted into a linear scale. The detected electromagnetic wave is handled as energy. Then, the data in the band of the broadcast wave and / or the communication wave is removed (replaced with level 0). For example, in an area where the first and third channels of TV broadcasting are used, 90-
Data in the 96 MHz and 102 to 108 MHz bands are removed. Then, the difference spectrum is obtained by subtracting the reference spectrum. As the reference spectrum, a spectrum of background noise detected without partial discharge is used as described later. After that, the cumulative integrated spectrum is further obtained for a predetermined frequency band. The presence or absence of partial discharge can be determined from the level and slope of this cumulative integrated spectrum. Furthermore, in order to automatically determine the presence or absence of partial discharge, the integrated value over a prescribed band of the difference spectrum is compared with a reference value, and if the reference value is exceeded, the energy of the electromagnetic waves generated by the partial discharge is present. Therefore, the abnormality detection output is performed. Even if the integrated value does not exceed the reference value, the slope of the cumulative integrated spectrum is extracted, the size of the slope is compared with the reference value, and if the slope exceeds the reference value, an abnormality detection output is also issued. , If not, normal detection output is performed.

FIG. 3 is a flow chart showing a processing procedure for creating the reference spectrum. First, read the frequency spectrum data of the electromagnetic wave in the state where partial discharge has not occurred, convert the level to a linear scale,
Similarly, the data of the specific frequency band is removed and this is stored as the reference spectrum.

Here, using the partial discharge detection device,
FIG. 11 shows a conceptual diagram of a method for specifically inspecting an abnormality of a distribution line pole device. In FIG. 11, 101a and 101
Reference character b denotes a distribution line pillar (hereinafter, simply referred to as a utility pole in the embodiment), and 102a and 102b denote pole transformers mounted on the respective utility poles. Further, reference numeral 100 is a measuring vehicle equipped with the partial discharge detecting device, and an antenna 1 is projected on the vehicle. Since these utility poles are usually erected along the road, the measurement vehicle 100 travels along the road and sequentially measures while stopping under each utility pole.

Next, an example of a specific measurement result will be given.

FIG. 4 shows a result obtained by converting the frequency spectrum detected at a plurality of points into a linear scale, removing a specific frequency band, and further subtracting the components of the reference spectrum. In the figure, “Namerikawa 2400” is the result of measurement under the telephone pole named Namerikawa 2400 in Namerikawa,
“Suburbs 8913” and “suburbs 0100” are measurement results at different points (numbers of predetermined points for comparison) in the suburbs, and “levee” is measurement results at certain points on a certain leve. . In this case, as the reference spectrum, a spectrum measured under a utility pole with "Namerikawa 2300" as a reference without partial discharge is used.

[0036] Figure 5 after converting the frequency spectrum of the electromagnetic wave due to background noise and partial discharge of each location in the linear scale, shows the results of cumulative integral for more bandwidth 40MHz and have respectively Nitsu. In this way, the cumulative integrated spectrum changes to a low level at the point where the electromagnetic waves due to the partial discharge are not received, whereas at the point where the partial discharge is generated (in the factory), 40 MHz to 120 MHz.
Has a large slope in the frequency band of 200 MHz
The integrated value at shows a large value. Note that the cumulative integrated spectrum in the suburbs 8913 sharply rises at 144 MHz, but this is due to the influence of radio waves for commercial radio, and if this band is also removed in the previous stage, the accumulation due to the presence or absence of partial discharge will occur. The difference in the integrated spectrum becomes clearer.

Even when the differential spectrum obtained by subtracting the reference frequency spectrum from the linear-scale frequency spectrum of the detected signal is cumulatively integrated, when the electromagnetic waves due to the partial discharge are received, the slope to the right is similarly large. Therefore, the integrated value in a certain range also becomes larger than that in the case without partial discharge.

In the example shown in FIG. 11, the pole transformer 10 is temporarily used.
If 2a is normal, the spectrum measured under the utility pole 101a is BG like the thick line (factory) in the example shown in FIG.
When the pole transformer 102b is partially discharged, the spectrum measured under the power pole 101b becomes a spectrum as shown in FIG.
Power pole 10 based on the spectrum measured under a.
When the spectra measured under 1b are compared, the cumulative integrated spectrum rises significantly as shown in FIG. 5, which allows the partial discharge of the pole transformer 102b to be detected.

As a comparative example, FIG. 6 shows a difference spectrum at each point when data in the broadcast frequency band is not removed. In the figure, some peaks appearing at 90 to 108 MHz are due to the broadcast waves of the first and third channels of FM broadcasting and TV broadcasting. FIG. 7 shows the cumulative integral spectrum at each point and the cumulative integral spectrum when partial discharge is generated without removing such components of the broadcast wave. The difference from the case shown in FIG. 5 is that, except that the band of the broadcast wave is not removed, the Namerikawa 2300 is based on the Namerikawa 2300.
That is, it is a cumulative integral spectrum of the difference spectrum obtained by subtracting the spectrum of the linear scale, and the integration range is 0 MHz or more. Therefore, although the cumulative integrated spectrum at each point is based on the difference spectrum based on Namerikawa 2300,
Due to the influence of communication waves used at 0 to 40 MHz, the cumulative integrated value increased considerably even at the point where there was no partial discharge, and the influence of TV broadcast waves around 100 MHz also caused partial discharge. In this case, the difference from the cumulative integrated spectrum pattern is not clear.

According to the present invention, it is possible to reliably detect the occurrence of a weak partial discharge without being affected by the broadcast wave or the communication wave without the above-mentioned problems.

According to the embodiment of the present invention, the frequency spectrum is handled on the linear scale.
Compared with the scale, the numerical difference becomes large, and there is an advantage that it is clarified in comparison with the reference spectrum.

[0042]

According to the present invention, since spectrum data is taken in for a wide frequency band, partial discharge due to tuning deviation is not overlooked as compared with the conventional frequency tuning method.

Further, since known frequencies of relatively large level such as broadcast waves and / or communication waves are excluded, the S / N ratio is improved. Furthermore, since the pattern comparison is not performed on the frequency spectrum but the cumulative integration spectrum is compared, the pattern difference becomes clear, and it becomes easy to grasp the presence or absence of partial discharge.

Further, particularly when a device on a distribution line pole is targeted, by using an external electromagnetic wave under an adjacent distribution line pole as a reference electromagnetic wave, a pattern of an electromagnetic wave different in a region, a place, or a time zone can be obtained. It is possible to make detailed determinations that include features.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a partial discharge detection device according to an embodiment of the present invention.

FIG. 2 is a flowchart showing a processing procedure of a CPU shown in FIG.

FIG. 3 is a flowchart showing a processing procedure of a CPU shown in FIG.

FIG. 4 is a diagram showing an example of a difference spectrum at each point.

FIG. 5 is a diagram showing an example of a cumulative integral spectrum at each point and a cumulative integral spectrum at a place where a partial discharge is generated.

FIG. 6 is a diagram showing an example of a differential spectrum when TV broadcast waves and FM broadcast waves are not removed.

FIG. 7 is a diagram showing an example of a cumulative integral spectrum at each point and a differential spectrum at a place where a partial discharge is generated.

FIG. 8 is a diagram showing a log-scale frequency spectrum at each point.

FIG. 9 is a diagram showing a frequency spectrum and a background noise spectrum when a partial discharge is generated.

10 is an S obtained by subtracting the spectrum of background noise from the spectrum of partial discharge in FIG.
It is a figure which shows / N component.

FIG. 11 is a conceptual diagram when inspecting equipment on a distribution line pole by a measuring vehicle equipped with a partial discharge detection device according to an embodiment.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hiromi Ishii, 47 Umezu Takaunecho, Ukyo-ku, Kyoto City, Kyoto Prefecture Nissin Electric Co., Ltd. Electric Power Co., Ltd. (72) Inventor Shigeru Nishikawa 15-1 Ushijimacho, Toyama City, Toyama Prefecture Hokuriku Electric Power Co., Inc.

Claims (7)

(57) [Claims] 1. A method for detecting partial discharge of an electric device, which detects an electromagnetic wave generated by a partial discharge generated in an electric device, the method comprising: detecting a frequency spectrum of an electromagnetic wave to be detected and a reference electromagnetic wave; Then, the corrected spectrum is obtained by removing the components of the broadcast wave and / or the communication wave band from the frequency spectrum, and the corrected spectrum is integrated over a certain frequency range to obtain the cumulative integrated spectrum. Partial discharge detection method for electrical equipment, which detects the occurrence status of partial discharge by comparing the cumulative integrated spectra of. 2. A partial discharge detection device for an electric device, which detects an electromagnetic wave generated by a partial discharge generated in an electric device to detect the partial discharge. A frequency for obtaining a frequency spectrum of each of the detected electromagnetic wave and the reference electromagnetic wave. A spectrum analysis means, a correction spectrum generation means for removing a component of a band of a broadcast wave and / or a communication wave from the obtained frequency spectrum to obtain a correction spectrum, and a cumulative integration spectrum by integrating the correction spectrum in a constant frequency range. A partial discharge detection device for electric equipment, comprising: a spectrum cumulative integration means for obtaining. 3. A partial discharge detection device for an electric device, which detects an electromagnetic wave generated by a partial discharge generated in an electric device to detect the partial discharge. A frequency for obtaining a frequency spectrum of each of the detected electromagnetic wave and the reference electromagnetic wave. A spectrum analysis means, a correction spectrum generation means for removing a component of a band of a broadcast wave and / or a communication wave from the obtained frequency spectrum to obtain a correction spectrum; and a correction spectrum for the detected electromagnetic wave with respect to the correction spectrum for the reference electromagnetic wave. A partial discharge detection device for an electric device, comprising: a difference spectrum generation means for obtaining a difference component of a correction spectrum; and a spectrum cumulative integration means for respectively integrating the difference spectrum in a constant frequency range to obtain a cumulative integration spectrum. 4. A partial discharge detection apparatus for an electric device, which detects an electromagnetic wave generated by a partial discharge generated in an electric device to detect the partial discharge. A frequency for obtaining a frequency spectrum of each of the detected electromagnetic wave and the reference electromagnetic wave. A spectrum analysis means, a correction spectrum generation means for removing a component of a band of a broadcast wave and / or a communication wave from the obtained frequency spectrum to obtain a correction spectrum; and a correction spectrum for the detected electromagnetic wave with respect to the correction spectrum for the reference electromagnetic wave. The presence or absence of partial discharge is determined by difference spectrum generation means for obtaining a difference component of the correction spectrum, integration means for obtaining an integrated value of the difference spectrum in a constant frequency range, and comparison of the integrated value with a predetermined reference value. Judgment means, Tokara Partial discharge detection device of the electric device. 5. A partial discharge detection device for an electric device for detecting a partial discharge by detecting an electromagnetic wave generated by a partial discharge generated in an electric device, comprising: a frequency for obtaining a frequency spectrum of each of a detected electromagnetic wave and a reference electromagnetic wave. A spectrum analysis means, a correction spectrum generation means for removing a component of a band of a broadcast wave and / or a communication wave from the obtained frequency spectrum to obtain a correction spectrum; and a correction spectrum for the detected electromagnetic wave with respect to the correction spectrum for the reference electromagnetic wave. Difference spectrum generating means for obtaining a difference component of the correction spectrum, spectrum cumulative integrating means for integrating the difference spectrum in a constant frequency range to obtain a cumulative integral spectrum, and a slope of the cumulative integral spectrum with respect to a predetermined reference value Determination means for determining presence or absence of a partial discharge by small compared, partial discharge detection device of the electric device composed of capital. 6. The partial discharge detection target device is a distribution line pole device, and the detected electromagnetic wave is an external electromagnetic wave under a distribution line pole on which the pole device to be detected is mounted,
The method for detecting partial discharge of an electric device according to claim 1, wherein the reference electromagnetic wave is an external electromagnetic wave under another distribution line pillar adjacent to the distribution line pillar. 7. The partial discharge detection target device is a distribution line pole device, and the detected electromagnetic wave is an external electromagnetic wave under a distribution line pole on which the pole device to be detected is mounted,
The partial discharge detection device for an electric device according to claim 2, wherein the reference electromagnetic wave is an external electromagnetic wave under another distribution line pillar adjacent to the distribution line pillar.