JP6624045B2 - Portable corona discharge detector - Google Patents

Description

  The present invention relates to a portable corona discharge detection device that detects a corona discharge of an AC power supply equipment by detecting an ultrasonic wave generated due to the corona discharge.

  If the insulation deteriorates due to contamination or deformation in the operating AC power supply equipment, such as power transmission lines and outdoor substations, corona discharge may occur at that location, leading to radio interference and insulation breakdown. There is. Therefore, it is necessary to quickly detect and correct corona discharge in AC power supply equipment.

  2. Description of the Related Art A portable corona discharge detection device for detecting a corona discharge of an AC power supply facility is known, and the configuration is shown in FIGS. It is known that when a corona discharge occurs in an AC power supply, a high-band ultrasonic wave is generated with the corona discharge. The conventional portable corona discharge detection device 200 shown in FIGS. 3 and 4 is a device that detects corona discharge by detecting ultrasonic waves generated due to corona discharge. This apparatus 200 has an ultrasonic detection unit 10 including a parabolic sound collecting plate 12 and an ultrasonic microphone 16 supported by three arms 14A, 14B, 14C extending from the concave surface of the parabolic sound collecting plate. The ultrasonic detection unit 10 is configured so that the ultrasonic wave reflected from the parabolic sound collecting plate 12 can be detected by the ultrasonic microphone 16 and selectively detects ultrasonic waves from any one direction with high directivity. And convert it to an electrical signal. Therefore, when the user holds the grip 56 and directs the ultrasonic detection unit 10 to various points of the AC power supply equipment, the ultrasonic waves can be detected with high directivity from the point where corona discharge occurs.

  The electric signal obtained by the ultrasonic microphone 16 is processed by, for example, a method described in Patent Literature 1, and the processing result is displayed on a display 30 as an output device. When an ultrasonic wave due to corona discharge is detected, a warning sound is emitted from a speaker (not shown) as an output device.

  The portable corona discharge detection device 200 includes a laser light source 40. The laser light source 40 is configured to emit visible monochromatic light, for example, red laser light, in a direction in which the ultrasonic detection unit 10 detects ultrasonic waves. Therefore, the user can specify the exact location of the corona discharge by directly visually recognizing the laser irradiation site when the warning sound is sounding from the speaker.

JP-A-9-233679

  In the conventional portable corona discharge detection device 200, when a laser irradiation part is brighter than its surroundings, for example, when checking indoor AC power supply equipment, the laser irradiation part can be directly visually recognized. However, the present inventors, when inspecting the AC power supply equipment in a place where white light is strong, such as outdoors with strong sunlight, if the strong white light is applied to the laser irradiation part, the laser irradiation part cannot be directly viewed. It was recognized that there was a problem that it was not possible to specify the exact location where corona discharge occurred.

  In view of the above problems, an object of the present invention is to provide a portable corona discharge detection device capable of specifying an accurate location of corona discharge even in a place where white light is strong such as outdoors where sunlight is strong. .

The gist configuration of the present invention for solving the above problems is as follows.
(1) A portable corona discharge detection device that detects corona discharge of an AC power supply by detecting ultrasonic waves generated due to the corona discharge,
An ultrasonic detection device that selectively detects ultrasonic waves from any one direction and converts it into an electric signal,
A signal processing unit that processes the electric signal,
An output device that outputs a processing result of the signal processing unit;
In the one direction, a laser light source that emits visible monochromatic laser light,
Digital camera equipped with a display for photographing the one direction and displaying the photographed image,
A bandpass filter disposed in front of the lens of the digital camera and selectively transmitting light having the same wavelength as the wavelength of the visible monochromatic laser light,
A portable corona discharge detection device comprising:

  (2) The portable corona discharge detection device according to (1), further including a movable mechanism configured to move the bandpass filter between a position in front of the lens and a position retracted from the front of the lens. .

  ADVANTAGE OF THE INVENTION According to the portable corona discharge detection apparatus of this invention, the location where corona discharge generate | occur | produced correctly can be pinpointed also in places with strong white light, such as outdoors where sunlight is strong.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the portable corona discharge detection apparatus 100 by one Embodiment of this invention, (A) is a rear view, (B) is a left view. It is a figure explaining the position of the bandpass filter 70 in the portable corona discharge detection device 100, (A) When the bandpass filter is in front of the lens, (B) is the position where the bandpass filter retracted from the front of the lens. Is shown. It is a perspective view showing the conventional portable corona discharge detection device 200. It is a figure which shows the conventional portable corona discharge detection apparatus 200, (A) is a rear view, (B) is a left view.

  Referring to FIGS. 1A and 1B and FIGS. 2A and 2B, a portable corona discharge detection device 100 according to an embodiment of the present invention (hereinafter, also simply referred to as “device 100”). And the effect obtained by the configuration will be described.

  The portable corona discharge detection device 100 is a device that detects a corona discharge of an AC power supply facility by detecting an ultrasonic wave generated due to the corona discharge, and includes, as a main component, an ultrasonic detection unit 10. , A signal processing unit (not shown), a display 30 as an output device, a laser light source 40, a digital camera 60, and a band-pass filter 70. The ultrasonic detection unit 10 and the display 30 are attached to the upper end of the cylindrical holding portion 56.

  In this embodiment, the ultrasonic detection device 10 includes a parabolic sound collecting plate 12, three arms 14A, 14B, and 14C extending from the concave surface of the parabolic sound collecting plate, and an ultrasonic microphone supported by these three arms. 16 is included. The ultrasonic microphone 16 is disposed at the focal point of the parabolic sound collecting plate 12 or at a position near the focal point. Therefore, the ultrasonic wave reflected by the parabolic sound collecting plate 12 can be detected by the ultrasonic microphone 16. As described above, the ultrasonic detection device 10 can selectively detect ultrasonic waves from any one direction with a high directivity of, for example, about ± 8 degrees, and convert the ultrasonic signals into electric signals. Therefore, when the user holds the grip 56 and directs the ultrasonic detection unit 10 to various points of the AC power supply equipment, the ultrasonic waves can be detected with high directivity from the point where corona discharge occurs.

  The electric signal obtained by the ultrasonic microphone 16 is processed by a signal processing unit (not shown). The method can be a known method, for example, as described in Patent Document 1. Specifically, since the ultrasonic waves generated by the corona discharge of the AC power supply equipment generate intensities in synchronism with the power supply phase, when the obtained electric signal is subjected to frequency analysis, a double component of the power supply frequency appears strongly. By detecting the intensity of the double component, corona discharge can be detected without being affected by environmental noise other than ultrasonic waves due to discharge.

  The output device outputs a processing result of the signal processing unit. As the output device, as shown in FIG. 1A, a display 30 installed on the back of the parabolic sound collecting plate 12 and a speaker (not shown) can be given. The display 30 can display a sound pressure conversion value (dB) of a double component of the power frequency, a ratio of the double component of the power frequency to the detected sound, a measured waveform, a waveform after frequency analysis, and the like. . When an ultrasonic wave caused by corona discharge is detected, a warning sound can be emitted from a speaker.

  In this embodiment, the laser light source 40 is a laser pointer embedded with the ultrasonic microphone 16 and embedded in a unit supported by three arms 14A, 14B, and 14C. The laser light source 40 is arranged such that the irradiation direction of the laser light coincides with the above-mentioned arbitrary one direction, that is, the direction in which the ultrasonic detection unit 10 detects ultrasonic waves. That is, the laser light source 40 emits visible monochromatic laser light from the opening of the unit in the ultrasonic detection direction. Therefore, the user can specify the exact location of the corona discharge by directly visually recognizing the laser irradiation site when the warning sound is sounding from the speaker. Examples of the visible monochromatic laser light include red (for example, center wavelength 635 nm, spectrum width 3 nm), green (for example, center wavelength 532 nm, spectrum width 3 nm), and blue (for example, center wavelength 460 nm, spectrum width 3 nm).

  However, when strong white light shines on the laser-irradiated part, the laser-irradiated part cannot be directly visually recognized, and the exact location of the corona discharge cannot be specified. Therefore, the apparatus 100 of the present embodiment is characterized by employing a combination of the digital camera 60 and the band-pass filter 70.

  Referring to FIGS. 1A and 1B, the digital camera 60 is installed on a camera base 80 arranged on the display 30 and is fixed to the camera base 80 by a fixture 82. At this time, the digital camera 60 is installed so that the optical axis of the lens 64 is parallel to any one of the directions, that is, the direction in which the ultrasonic detection unit 10 detects ultrasonic waves. By doing so, the digital camera 60 can photograph the arbitrary position direction. Further, the digital camera 60 includes a display 62 for displaying a captured image in real time. The digital camera 60 is not particularly limited as long as it has the above functions, and for example, a smartphone having the above functions may be used. As shown in FIGS. 2A and 2B, the fixture 82 can be slidable with respect to the camera base 80 so as to correspond to the width and thickness of various digital cameras.

  Referring to FIG. 1B, the band-pass filter 70 is disposed perpendicularly to a filter support base 84 installed on a camera base 80, and is disposed in front of a lens 64 of the digital camera. Here, the bandpass filter 70 that selectively transmits light having the same wavelength as the wavelength of the visible monochromatic laser light emitted from the laser light source 40 is used. For example, if the laser light is red, use a center wavelength of 635 to 650 nm.If the laser light is green, use a center wavelength of 532 nm.If the laser light is blue, use The one having a center wavelength of 460 nm is used.

  In this way, even when strong white light is applied to the laser irradiation site, the white light of a color other than the color of the laser light in the image displayed on the display 62 of the digital camera. Is removed, and as a result, the laser irradiation site can be confirmed in the image. That is, even though the laser irradiation part cannot be visually recognized directly, the laser irradiation part can be visually recognized in the image on the display 62 of the digital camera. In this manner, the device 100 of the present embodiment can specify the exact location where corona discharge occurs, even in places with strong white light, such as outdoors with strong sunlight.

  Here, even when the conventional corona discharge detection device 200 shown in FIGS. 3 and 4 is used, if the user wears, for example, glasses to which a bandpass filter is attached, the laser irradiation site can be directly visually recognized. However, when inspecting the AC power supply equipment, it is extremely dangerous that the user walks with such glasses or performs the inspection work itself without walking, which limits the visibility of the user. It is accompanied by. On the other hand, the present embodiment is characterized by an apparatus configuration in which the laser irradiation site can be visually recognized through the display 62 of the digital camera by employing a combination of the digital camera 60 and the band-pass filter 70. For this reason, it is possible to specify the exact location of the corona discharge while ensuring the safety of the user.

  Referring to FIGS. 2A and 2B, the band-pass filter 70 is movable by a filter movable mechanism 86 between a position in front of the lens 64 and a position retracted from the front of the lens 64. Is preferred. The movable mechanism 86 is not particularly limited. For example, a hinge mechanism as shown in FIGS. 2A and 2B can be adopted. One flat plate of the hinge mechanism is fixed to the filter support base 84, and the other flat plate is fixed to the bandpass filter 70.

  The effects of adopting such a configuration are as follows. That is, conventionally, when inspecting AC power supply equipment, it has been common practice to carry a camera in addition to the corona discharge detection device to take a photograph of a location where corona discharge has occurred. According to the apparatus 100 of the present embodiment, the bandpass filter 70 is unnecessary when taking a picture of the location where the corona discharge occurs, and therefore, as shown in FIG. To the filter support base 84 side. As described above, according to the present embodiment, the mode in which the laser irradiation site is visually recognized and the corona discharge location is accurately specified (FIG. 2A), and the mode in which the accurately specified corona discharge location is photographed ( FIG. 2B) can also be used.

  Hereinafter, a method of using the device 100 of the present embodiment will be described. When inspecting the AC power supply, the user holds the grip 56 of the device 100 and turns the ultrasonic detection unit 10 toward various points of the AC power supply while pressing the button 50. That is, the measurement mode is a period in which the button 50 is pressed, the laser light is emitted from the laser light source 40, and the operations of the ultrasonic detection unit 10, the signal processing unit, and the output devices such as the display are turned on. When the ultrasonic detection unit 10 is directed to the corona discharge generation location, the ultrasonic waves generated from the location are detected, the above-described information is displayed on the display 30, and the speaker emits a warning sound. If the user cannot directly view the laser irradiation site at that time, the user checks the laser irradiation site in the real-time image output to the display 62 of the digital camera 60, and specifies the exact location of the corona discharge. . If necessary, the band-pass filter 70 is retracted, and the digital camera 60 takes a photograph of the occurrence location. The buttons 52 and 54 are used to change display settings (brightness and the like) and to turn on / off the power.

  In the present embodiment, a combination of the parabolic sound collecting plate 12 and the ultrasonic microphone 16 is adopted as the ultrasonic detecting device 10, but the present invention is not limited to this. For example, an ultrasonic microphone having high detection directivity may be used alone.

  ADVANTAGE OF THE INVENTION According to the portable corona discharge detection apparatus of this invention, the location where corona discharge generate | occur | produced correctly can be pinpointed also in places with strong white light, such as outdoors where sunlight is strong.

REFERENCE SIGNS LIST 100 portable corona discharge detection device 10 ultrasonic detection unit 12 parabolic sound collecting plate 14 A, 14 B, 14 C arm 16 ultrasonic microphone 30 display 40 laser light source 50, 52, 54 operation button 56 gripping unit 60 digital camera 62 display 64 lens Reference Signs List 70 band-pass filter 80 camera stand 82 fixture 84 filter support base 86 filter movable mechanism

Claims (1)

A portable corona discharge detection device that detects corona discharge of AC power supply equipment by detecting ultrasonic waves generated due to the corona discharge,
An ultrasonic detection device that selectively detects ultrasonic waves from any one direction and converts it into an electric signal,
A signal processing unit that processes the electric signal,
An output device that outputs a processing result of the signal processing unit;
In the one direction, a laser light source that emits visible monochromatic laser light,
Digital camera equipped with a display for photographing the one direction and displaying the photographed image,
A bandpass filter disposed in front of the lens of the digital camera and selectively transmitting light having the same wavelength as the wavelength of the visible monochromatic laser light,
A movable mechanism for moving the bandpass filter between a position in front of the lens and a position retracted from the front of the lens,
A portable corona discharge detection device comprising:

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