Switchgear partial discharge monitoring device and method

Abstract

The application discloses a kind of switch cabinet partial discharge monitoring device and method, wherein, method includes: when the partial discharge of switch cabinet cabinet wall occurs, vibration signal is generated;Distributed feedback laser is affected by vibration signal, deformation occurs, cause the wavelength of distributed feedback laser to change;Interferometer receives the laser emitted by distributed feedback laser, and the wavelength change of laser is converted into phase change, by monitoring phase change to realize the partial discharge monitoring of switch cabinet cabinet wall.The pin is made of rigid material, is easily affected by the vibration generated by the partial discharge of switch cabinet cabinet wall, so that the DFB laser inside pin is affected by vibration, the wavelength of output laser changes, by converting the monitoring of vibration signal into the monitoring of laser signal, avoid the interference caused by electromagnetic influence and noise influence in the environment when monitoring electromagnetic wave and sound wave in conventional means, improve the reliability of the partial discharge monitoring of switch cabinet cabinet wall.

Description

Technical Field

[0001] This invention relates to the field of power system technology, specifically to a partial discharge monitoring device and method for switchgear. Background Technology

[0002] Switchgear is widely used in power networks, playing an important role in ensuring the stability of the power system, protecting the safety of power transmission, and interrupting current when necessary.

[0003] Domestic and international scholars have conducted research on various faults in switchgear and explored related detection technologies, with partial discharge detection being the most prevalent area of ​​research. Partial discharge is a major cause of insulation breakdown in high-voltage electrical equipment. Each partial discharge can cause some damage to the insulating components. Small-volume partial discharges cause relatively little damage to the insulating materials, resulting in only a slight decrease in insulation reliability; however, large-volume partial discharges can lead to a significant drop in the reliability of the insulating materials.

[0004] There are three main methods for partial discharge detection in switchgear: ultrasonic detection, ground wave detection, and ultra-high frequency detection. Using only one detection method has limitations, so it is necessary to combine detection methods according to the actual situation, which can lead to inconvenience in the detection layout. Summary of the Invention

[0005] In view of this, embodiments of the present invention provide a device and method for monitoring partial discharge in switchgear, in order to solve the problem that existing methods for detecting partial discharge in switchgear require combined detection and have inconvenient detection layout.

[0006] This invention provides a partial discharge monitoring device for switchgear, comprising:

[0007] Distributed feedback laser;

[0008] The insert has an inner diameter that matches the outer diameter of the distributed feedback laser.

[0009] An interferometer is used to receive laser signals emitted by a distributed feedback laser.

[0010] The pin is made of rigid material; the distributed feedback laser is nested inside the pin; and the pin is fixed to the wall of the switch cabinet.

[0011] Alternatively, the pin may be made of polymer, metal, or ceramic.

[0012] Alternatively, the pins can be fixed to the switch cabinet wall using glass glue, silicone glue, AB glue, or hot melt glue.

[0013] Optionally, it also includes a phase detector electrically connected to the interferometer.

[0014] Optionally, the phase detector uses the AD8302 amplitude and phase measurement chip.

[0015] Optionally, a window is provided on the pin body, the outer side of the window is open, the inner side of the window communicates with the internal space of the pin, and a screw hole is provided on the surface of the pin body on both sides of the window.

[0016] Optionally, the window is fan-shaped, and the plane of the window is perpendicular to the axis of the pin.

[0017] Optionally, a sector-shaped block is movably disposed in the window, the sector-shaped block moves along the inner wall of the window, and the inner side of the sector-shaped block abuts against the side wall of the distributed feedback laser; the radius of the sector-shaped block is larger than the radius of the window, and an extension is provided on the outer side of the sector-shaped block, and a through hole is provided on the extension, and the sector-shaped block is fixed in the screw hole by bolts passing through the through hole.

[0018] The beneficial effects of this embodiment are as follows: by converting the monitoring of vibration signals into the monitoring of laser signals, the interference caused by electromagnetic influences and noise in the environment is avoided when monitoring electromagnetic waves and sound waves in conventional methods, thereby improving the reliability of monitoring partial discharge on the switch cabinet wall.

[0019] This invention also provides a method for monitoring partial discharge in switchgear, applied to the aforementioned switchgear partial discharge monitoring device, comprising:

[0020] When partial discharge occurs on the wall of the switch cabinet, a vibration signal is generated;

[0021] Distributed feedback lasers are affected by vibration signals, causing deformation and resulting in changes in the wavelength of the distributed feedback laser.

[0022] The interferometer receives the laser emitted by the distributed feedback laser and converts the wavelength change of the laser into a phase change. By monitoring the phase change, partial discharge monitoring of the switch cabinet wall can be achieved.

[0023] Optionally, it also includes:

[0024] The phase change converted by the interferometer is demodulated to obtain the intensity and frequency of the vibration signal.

[0025] The beneficial effects of this embodiment are as follows: by converting the monitoring of vibration signals into the monitoring of laser signals, the interference caused by electromagnetic influences and noise in the environment is avoided when monitoring electromagnetic waves and sound waves in conventional methods, thereby improving the reliability of monitoring partial discharge on the switch cabinet wall. Attached Figure Description

[0026] The features and advantages of the invention will be more clearly understood by referring to the accompanying drawings, which are schematic and should not be construed as limiting the invention in any way. In the drawings:

[0027] Figure 1 A schematic diagram of a distributed feedback laser in a switchgear partial discharge monitoring device according to Embodiment 1 of the present invention is shown;

[0028] Figure 2 A schematic diagram of the pins of a partial discharge monitoring device for switchgear according to Embodiment 1 of the present invention is shown;

[0029] Figure 3 A schematic diagram of the window structure in Embodiment 2 of the present invention is shown;

[0030] Figure 4 A schematic diagram of the installation structure of the sector block in Embodiment 2 of the present invention is shown;

[0031] Figure 5 The window cross-sectional view in Embodiment 2 of the present invention is shown;

[0032] Figure 6 A cross-sectional view of the sector block in Embodiment 2 of the present invention is shown. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] Example 1

[0035] This invention provides a partial discharge monitoring device for switchgear, such as... Figure 1 and Figure 2 As shown, the device includes a distributed feedback laser 300, a pin 100, and an interferometer. The pin 100 has a channel 200 extending through its central axis. The inner diameter of the pin 100 is the same as the outer diameter of the distributed feedback laser 300, ensuring that the distributed feedback laser 300 fits snugly against the inner wall of the pin 100, preventing gaps that could lead to inaccurate vibration data reception. The interferometer receives the laser signal emitted by the distributed feedback laser 300. The pin 100 is made of a rigid material. The distributed feedback laser 300 is nested inside the pin 100. The pin 100 is fixed to the wall of the switch cabinet.

[0036] In this embodiment, when partial discharge occurs at the busbar cable joints or other locations in the switchgear, vibration signals are generated. These vibration signals cause deformation of the sensing head of the Distributed Feedback Laser (DFB) 300, which is attached to the switchgear wall. This deformation leads to a change in the wavelength of the DFB laser. An interferometer converts this wavelength change into a phase change, thereby enabling the monitoring of partial discharge in the switchgear. The DFB laser is characterized by its small size, light weight, resistance to electromagnetic interference, non-energized all-optical probe, high sensitivity, and large dynamic range. By converting the monitoring of vibration signals into the monitoring of laser signals, interference caused by environmental electromagnetic influences and noise, which is present in conventional methods for monitoring electromagnetic and acoustic waves, is avoided, thus improving the reliability of partial discharge monitoring on the switchgear wall.

[0037] In a specific embodiment, the sensing head consists of a DFB laser with an outer diameter of 250 μm and a length of approximately 40 mm, and a pin 100 with an inner diameter of 250 μm and a length matching that of the DFB laser. The DFB laser is inserted into the pin 100 to form the sensing head. The sensing head is attached to the wall of the switchgear cabinet. When the vibration signal generated by the discharge is transmitted to the pin 100, the pin 100 vibrates, and this vibration signal is transmitted to the DFB laser. This causes a change in its resonant wavelength, which is then demodulated using an interferometer to detect the vibration signal generated by the discharge.

[0038] As an optional implementation, the pin 100 may be made of polymer, metal or ceramic.

[0039] As an optional implementation, the pin 100 is fixed to the switch cabinet wall by glass glue, silicone glue, AB glue or hot melt glue.

[0040] As an optional implementation, it also includes a phase detector electrically connected to the interferometer. In a specific embodiment, the phase detector uses an AD8302 amplitude-phase measurement chip.

[0041] In this embodiment, the wavelength changes demodulated by the interferometer are analyzed and processed by the AD8302 amplitude and phase measurement chip to obtain the intensity and frequency of the vibration signal, thereby further realizing the monitoring of partial discharge on the switch cabinet wall.

[0042] Example 2

[0043] In practical applications, for ease of installation, it is impossible to guarantee a 100% fit between the distributed feedback laser 300 and the pin 100 without any gaps. When gaps appear between them, the vibrations of the distributed feedback laser 300 and the pin 100 cannot be synchronized, resulting in inaccurate vibration signals.

[0044] Therefore, such as Figure 3-6 As shown, the present invention provides a window 400 on the body of the pin 100. The outer side of the window 400 is open, and the inner side of the window 400 is in communication with the internal space of the pin 100, so that it can contact the distributed feedback laser 300 inserted in the channel 200. A screw hole 500 is provided on the surface of the body of the pin 100 on both sides of the window 400.

[0045] In this embodiment, the window 400 is fan-shaped, and the plane of the window 400 is perpendicular to the axis of the pin 100. A fan-shaped block 600 is movably disposed in the window 400, and the main fan-shaped structure 620 of the fan-shaped block 600 matches the internal space of the window 400. The fan-shaped block 600 moves along the inner wall of the window 400, and the inner side of the fan-shaped block 600 is also an arc-shaped structure, which abuts against the side wall of the distributed feedback laser 300. The radius of the fan-shaped block 600 is larger than the radius of the window 400. An extension 630 is provided on the outer side of the fan-shaped block 600, and a through hole 610 is provided through the extension 630. The fan-shaped block 600 is fixed in the screw hole 500 by bolts passing through the through hole 610.

[0046] After the distributed feedback laser 300 is inserted into the channel 200, the sector block 600 is fixed to the outside of the pin 100 body by bolts. Since the radius of the sector block 600 is slightly larger than the radius of the window 400, as the bolt is screwed into the screw hole 500 to a greater depth, the inner side of the sector block 600 fits against the side wall of the distributed feedback laser 300, thus pressing the distributed feedback laser 300 tightly against the channel 200. This eliminates any gaps that may exist between the distributed feedback laser 300 and the pin 100, allowing them to vibrate synchronously and improving the measurement accuracy of the vibration signal.

[0047] Example 3

[0048] This invention also provides a method for monitoring partial discharge in switchgear, applied to the switchgear partial discharge monitoring device in Embodiment 1, comprising:

[0049] S1 generates a vibration signal when partial discharge occurs on the switch cabinet wall.

[0050] S2, the distributed feedback laser 300 is affected by the vibration signal and undergoes deformation, causing a change in the wavelength of the distributed feedback laser 300.

[0051] S3, the interferometer receives the laser emitted by the distributed feedback laser 300 and converts the wavelength change of the laser into a phase change. By monitoring the phase change, partial discharge monitoring of the switch cabinet wall is achieved.

[0052] In this embodiment, since the pin 100 is made of rigid material, it is easily affected by the vibration generated by partial discharge of the switch cabinet wall. This causes the DFB laser inside the pin 100 to change the output laser wavelength due to the vibration. By converting the monitoring of vibration signals into the monitoring of laser signals, the interference caused by electromagnetic influence and noise in the environment is avoided when monitoring electromagnetic waves and sound waves in conventional methods, thus improving the reliability of monitoring partial discharge of the switch cabinet wall.

[0053] As an optional implementation, it also includes:

[0054] The phase change converted by the interferometer is demodulated to obtain the intensity and frequency of the vibration signal.

[0055] In this embodiment, the AD8302 amplitude-phase measurement chip is used to process and analyze the phase information output by the interferometer. Specifically, the AD8302 amplitude-phase measurement chip takes the phase signal output by the DFB laser under normal conditions as one input and the phase signal output by the DFB laser under vibration as another input. The amplitude ratio and phase difference of these two input signals are measured to analyze the amplitude and frequency of the vibration signal caused by partial discharge in the switch cabinet wall. Then, multiple vibration signals are combined with the corresponding partial discharge conditions to process and feed back the specific partial discharge information of the switch cabinet wall.

[0056] This invention improves the reliability of monitoring partial discharge on switchgear walls by converting the monitoring of vibration signals into the monitoring of laser signals, thus avoiding interference caused by electromagnetic and noise effects in the environment when monitoring electromagnetic and acoustic waves using conventional methods.

[0057] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A switchgear partial discharge monitoring device, characterized by, It comprises: a distributed feedback laser; a pin, the inner diameter of which is consistent with the outer diameter of the distributed feedback laser; an interferometer, which is used to receive the laser signal emitted by the distributed feedback laser; wherein the pin is made of rigid material; the distributed feedback laser is nested in the pin; and the pin is fixed on the wall of a switch cabinet; a window is formed on the pin body, the window is open on the outside, and the inside of the window is connected with the internal space of the pin; a screw hole is formed on the surface of the pin body on both sides of the window; a sector-shaped block is movably arranged in the window, the sector-shaped block moves along the inner wall of the window, and the inner side of the sector-shaped block is in contact with the side wall of the distributed feedback laser; the radius of the sector-shaped block is greater than the radius of the window, an extension is arranged on the outer side of the sector-shaped block, a through hole is formed in the extension, and the sector-shaped block is fixed in the screw hole through the through hole and a bolt.

2. The switchgear partial discharge monitoring device of claim 1, wherein, The material of the pin is polymer, metal or ceramic.

3. The switchgear partial discharge monitoring device of claim 1, wherein, The pin is fixed on the wall of the switch cabinet by glass glue, silicone glue, AB glue or hot melt glue.

4. The switchgear partial discharge monitoring device of claim 1, wherein, It further comprises: a phase detector, which is electrically connected with the interferometer.

5. The switchgear partial discharge monitoring device of claim 4, wherein, The phase detector is an AD8302 amplitude-phase measurement chip.

6. The switchgear partial discharge monitoring device of claim 5, wherein, The window is in the shape of a sector, and the plane of the window is perpendicular to the axial direction of the pin.

7. A method for monitoring partial discharge of a switchgear, applied to the switchgear partial discharge monitoring device according to any one of claims 1 to 6, characterized in that, It comprises: When partial discharge occurs on the wall of a switch cabinet, a vibration signal is generated; The distributed feedback laser is affected by the vibration signal and deforms, which causes the wavelength of the distributed feedback laser to change; The interferometer receives the laser emitted by the distributed feedback laser and converts the wavelength change of the laser into phase change, and the partial discharge monitoring of the wall of the switch cabinet is realized by monitoring the phase change.

8. The switchgear partial discharge monitoring method of claim 7, wherein, It further comprises: The demodulation of the phase change converted by the interferometer is performed to obtain the intensity and frequency of the vibration signal.

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