Partial discharge sensing device of transformer

Abstract

The present invention relates to a partial discharge sensing device of a transformer, which detects partial discharge in the transformer and is capable of measuring its position. A partial discharge sensing apparatus of a transformer according to one embodiment may include: a housing provided in the transformer and having a hollow portion; the first omnidirectional sensor is arranged on one side in the shell and detects a partial discharge signal of the transformer; and a directional second sensor disposed on the other side in the housing and detecting a partial discharge signal of the transformer.

Description

Technical Field

[0001] The present invention relates to a partial discharge sensing device for a transformer for detecting partial discharge in the transformer and measuring the location of the partial discharge. Background Art

[0002] Usually, partial discharge occurs before an accident due to the degradation of the transformer's insulation performance. Therefore, when partial discharge occurs, the defective part should be found, inspected and repaired.

[0003] To locate the location of partial discharge within a transformer, an inspector visually inspects the interior of the transformer or determines the location of partial discharge within the transformer based on past experience. However, due to the sealed nature of the transformer casing, locating the location of partial discharge within the transformer is difficult. Furthermore, since the transformer must be shut down and the insulating oil drained to locate the location of the partial discharge, this method incurs significant costs.

[0004] To address this issue, methods have been proposed to estimate the location of partial discharges in operating transformers using ultrasonic or ultra-high frequency signals. However, the low level of ultrasonic signals makes it difficult to measure their location. Furthermore, high-precision position measurement requires the installation of four or more sensors within the transformer. Summary of the Invention Technical issues

[0005] The present invention relates to a partial discharge sensing device for a transformer for detecting partial discharge in the transformer and measuring the location of the partial discharge. Solution to the problem

[0006] According to one aspect of the present disclosure, a partial discharge sensing device may include: a housing disposed in a transformer and having a hollow portion; an omnidirectional first sensor disposed on one side of the housing and detecting partial discharge signals of the transformer; and a directional second sensor disposed on the other side of the housing and detecting partial discharge signals of the transformer.

[0007] The first sensor and the at least one second sensor may be ultra high frequency sensors.

[0008] The partial discharge sensing apparatus may further include a third sensor disposed within the housing and detecting light within the transformer.

[0009] The housing may be at least partially formed with a transparent window.

[0010] The partial discharge sensing device may further include: a first support tube having a flange portion and a tubular extension portion; a second support tube penetrating the extension portion and having a housing fixed at one end; and a signal line connector mounted at the other end of the second support tube and capable of connecting a signal line.

[0011] The partial discharge sensing device can be installed in the oil drain valve of the transformer. Advantageous Effects of the Invention

[0012] According to the embodiments of the present disclosure, partial discharge within a transformer can be detected without stopping the operation of the transformer, and the location of the partial discharge can be measured with high accuracy, thereby minimizing the time and economic loss required to find the location of the partial discharge.

[0013] Furthermore, according to the embodiments of the present disclosure, when partial discharge occurs, defective parts in the transformer can be quickly discovered and measures can be taken, thereby preventing accidents in the transformer in advance. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 1 is a front view and a partially enlarged cross-sectional view of a partial discharge sensing device according to an embodiment of the present disclosure.

[0015] Figure 2 FIG. 1 is a diagram illustrating a state where a partial discharge sensing device according to an embodiment of the present disclosure is installed on a transformer. DETAILED DESCRIPTION

[0016] Hereinafter, the present disclosure will be described in detail with reference to the exemplary drawings. It should be noted that when adding reference numerals to components of each drawing, even if the same components are shown in different drawings, they are denoted by the same numerals.

[0017] Figure 1 1 is a front view and a partially enlarged cross-sectional view of a partial discharge sensing device according to an embodiment of the present disclosure.

[0018] The partial discharge sensing apparatus for a transformer according to an embodiment of the present disclosure may include a housing 10 , an omnidirectional first sensor 20 , and a directional second sensor 30 .

[0019] The housing 10 may be formed with a hollow portion to store components therein and protect the components from various factors within the transformer, such as high voltage, insulating oil, etc. The housing may be formed of a strong and insulating material, such as plastic, silicone, or ceramic.

[0020] The first sensor 20 may be disposed at one side of the housing 10 and may detect a partial discharge signal of the transformer. The first sensor has omnidirectionality, so that equal gain may be obtained in all directions, vertically and horizontally.

[0021] For example, the first sensor 20 may be an ultra high frequency (UHF) sensor. The first sensor may receive an electromagnetic wave signal radiated by partial discharge in the UHF frequency band of approximately 300 MHz to 1600 MHz.

[0022] When partial discharge occurs inside a transformer, electromagnetic signals are emitted in a wide frequency range. The first sensor 20 used in the partial discharge sensing device according to an embodiment of the present disclosure receives electromagnetic signals in the UHF band.

[0023] In this case, the first sensor 20 should efficiently detect partial discharge signals from all parts within the transformer and thus have omnidirectionality capable of receiving signals in all directions.

[0024] At least one second sensor 30 may be disposed on the other side of the housing 10 to detect a partial discharge signal of the transformer. The second sensor has a directional property so that gain can be obtained in a specific direction.

[0025] For example, the second sensor 30 may be a UHF sensor. The second sensor may receive electromagnetic wave signals radiated by partial discharge in the UHF frequency band of approximately 300 MHz to 1600 MHz.

[0026] When partial discharge occurs in a transformer, electromagnetic signals are emitted in a wide frequency range. The second sensor 30 used in the partial discharge sensing device according to an embodiment of the present disclosure receives electromagnetic signals in the UHF band.

[0027] Furthermore, the second sensor 30 has a directional property, so that the partial discharge signal can be detected from a specific portion within the transformer.

[0028] The partial discharge sensing device according to an embodiment of the present disclosure may have at least two sensors 20 and 30 embedded therein, such that each sensor can detect a partial discharge signal (i.e., an electromagnetic wave signal in the UHF band) and can obtain distance information from the arrival time difference, signal magnitude, etc. of the signals detected by the sensor.

[0029] Furthermore, the second sensor 30 may gain gain from a specific direction, so that direction information can be acquired from the direction of a signal detected by the sensor.

[0030] Therefore, since the distance between the partial discharge sensing device and the defect source where partial discharge occurs and the direction of the defect source relative to the partial discharge sensing device can be known, the position of the defect source generating the partial discharge signal in the transformer can be measured.

[0031] In the prior art, at least four sensors are installed inside a transformer to measure the location of partial discharge. However, the partial discharge sensing device according to an embodiment of the present disclosure has the advantage of being able to measure the location of partial discharge with much higher accuracy than conventional methods using only two sensors (i.e., a directional second sensor and an omnidirectional first sensor).

[0032] Furthermore, due to the above-described configuration and operation, the partial discharge sensing device according to the embodiment of the present disclosure can achieve the effect of significantly reducing the time and cost required to find the location of partial discharge.

[0033] The partial discharge sensing apparatus for a transformer according to an embodiment of the present disclosure may further include a third sensor 40 disposed within the housing 10 and detecting light within the transformer. The third sensor may be a light sensor or a light intensity sensor, such as a phototransistor, a photoresistor, or a photodiode.

[0034] In addition, for light detection by the third sensor 40, a window 11 formed of a transparent material that at least partially transmits light may be formed in the housing 10. The window may be provided in the housing at least at a portion corresponding to the third sensor.

[0035] By installing a third sensor 40 including a light sensor or a light intensity sensor on the partial discharge sensing device, the light signal of the arc generated in the transformer can be detected. Therefore, the partial discharge sensing device according to the embodiment of the present disclosure can distinguish between the arc and partial discharge occurring in the transformer.

[0036] Meanwhile, the partial discharge sensing device according to an embodiment of the present disclosure may be installed in the oil drain valve 2 of the transformer housing 1. To this end, the partial discharge sensing device for the transformer according to an embodiment of the present disclosure may further include a first support tube 50, a second support tube 60, and a signal line connector 70.

[0037] The first support pipe 50 may be coupled to the oil drain valve 2 of the transformer. To this end, the first support pipe may include a flange portion 51 and a tubular extension portion 52.

[0038] The flange portion 51 may serve as a coupling portion having a larger diameter than the extension portion 52 of the first support pipe 50 for connection with the oil discharge valve 2. The flange portion may include a plurality of screw holes (not shown) formed at regular intervals in the circumferential direction.

[0039] Bolts, nuts, etc. may be fastened to the flange portion 51 together with a corresponding flange of the oil discharge valve 2 , so that the first support pipe 50 may be connected to the oil discharge valve.

[0040] The extension portion 52 extends from one side surface of the flange portion 51 and has a hollow structure with a hollow interior. Therefore, the second support tube 60 can be mounted and supported on the first support tube 50 by passing through the hollow extension portion.

[0041] The extension portion 52 may be further provided with a vent valve 53 and a fastening nut 54 .

[0042] The exhaust valve 53 may be opened to exhaust air that may be introduced when the partial discharge sensing apparatus of the present disclosure is installed.

[0043] After the second support tube 60 passes through the first support tube 50 and is inserted into the transformer housing 1 through the oil drain valve 2 , the fastening nut 54 can tighten the opening of the extension portion 52 to fix the insertion length of the second support tube 60 .

[0044] The second support tube 60 may be formed as a long tubular member having a hollow interior. The housing 10 may be fixed to one end of the second support tube by, for example, screwing, bonding, or the like.

[0045] Second support tube 60 not only extends through extension 52 of first support tube 50 but is also movable relative to the extension. When the second support tube extends through the first support tube and is inserted into transformer housing 1 through oil drain valve 2, and then tightened by nut 54 to secure the opening of the extension, the insertion length of the second support tube within the transformer housing (in other words, the positions of housing 10 and sensors 20, 30, and 40 within the transformer housing) is fixed.

[0046] A signal line connector 70 may be installed at the other end of the second support tube 60. An output line of each of the sensors 20, 30, and 40 constituting the partial discharge sensing device of the present disclosure may be connected to the inside of the signal line connector, and a signal line (not shown) extending to the outside of the transformer and connected to the signal analysis device may be connected to the outside of the signal line connector.

[0047] However, output of signals is not necessarily limited to wired communication, and for example, when outputting signals from the partial discharge sensing device of the present disclosure to a signal analysis device via wireless communication, the signal line and the signal line connector may be omitted.

[0048] Next, a method for installing the partial discharge sensing device according to an embodiment of the present disclosure is briefly described.

[0049] Figure 2 FIG. 1 is a diagram illustrating a state where a partial discharge sensing device is installed in a transformer according to an embodiment of the present disclosure.

[0050] After preparing the partial discharge sensing device, a worker holds the flange 51 and pulls the second support tube 60 to bring the housing 10 and the flange 51 into close contact as possible. The oil drain valve 2 of the transformer housing 1 can then be combined with the partial discharge sensing device. For example, the flange 51 of the first support tube 50 and the flange of the oil drain valve 2 can be fastened using bolts, nuts, or the like.

[0051] Next, the oil drain valve 2 is opened to check for leakage between the first support pipe 50 and the oil drain valve 2 .

[0052] Afterwards, the worker pushes the second support tube 60 toward the oil drain valve 2, so that the housing 10 and sensors 20, 30, and 40 reach the desired position within the transformer housing. By tightening the openings with the fastening nut 54 of the extension 52 so that they can be fixed in the corresponding positions, the position of the second support tube relative to the first support tube 50 and the insertion length of the second support tube within the transformer housing can be fixed.

[0053] Next, the exhaust valve 53 of the extension 52 is opened to exhaust the air that may have been introduced during installation. This can prevent the formation of bubbles in the insulating oil in the transformer housing 1.

[0054] In this way, the partial discharge sensing device according to an embodiment of the present disclosure can be installed in a transformer.

[0055] Therefore, the partial discharge sensing device according to the embodiment of the present disclosure can obtain the advantage of being installed in a transformer in operation without requiring a dedicated mounting structure.

[0056] Once installation of the partial discharge sensing device is complete, the signal line is connected to the signal line connector 70, thereby allowing the partial discharge sensing device to be electrically connected to the signal analysis device.

[0057] The signal analysis device can analyze the partial discharge signal and / or optical signal provided by the partial discharge sensing device to distinguish between arc and partial discharge occurring in the transformer and easily and accurately measure the location of the defect source generating the partial discharge signal in the transformer.

[0058] As described above, according to the partial discharge sensing device of the embodiment of the present disclosure, when partial discharge occurs, defective parts in the transformer can be quickly discovered and measures can be taken, thereby having the effect of preventing transformer accidents in advance.

[0059] The above description is merely an example of the technical idea of ​​the present disclosure, and it will be apparent to those skilled in the art that modifications and variations may be made without departing from the scope of the present disclosure as defined by the appended claims.

[0060] Therefore, the embodiments disclosed in the specification and the drawings are not intended to limit the technical concept of the present disclosure, but are used for explanation, and the scope of the technical concept of the present disclosure is not limited by these embodiments. The scope of protection of the present disclosure should be interpreted according to the scope of the claims, and all technical concepts within the scope equivalent to the claims should be interpreted as included within the scope of the present disclosure. Industrial Applicability

[0061] The present disclosure is useful for finding defective locations and performing inspection and repair when partial discharge occurs in a transformer during operation.

Claims

1. A partial discharge sensing device, comprising: a housing provided in the transformer and having a hollow portion; an omnidirectional first sensor, disposed on one side of the housing and detecting a partial discharge signal of the transformer; as well as A second sensor is directed to be disposed at the other side of the housing and to detect the partial discharge signal of the transformer.

2. The partial discharge sensing device according to claim 1, wherein: The first sensor and at least one of the second sensors are ultra high frequency (UHF) sensors.

3. The partial discharge sensing device of claim 1 , further comprising: A third sensor is disposed within the housing and detects light within the transformer.

4. The partial discharge sensing device according to claim 3, wherein: The housing is at least partially formed with a transparent window.

5. The partial discharge sensing device of claim 1 , further comprising: a first support tube, the first support tube having a flange portion and a tubular extension portion; a second support tube, the second support tube passing through the extension portion and having the housing fixed at one end; as well as A signal line connector is installed at the other end of the second support tube and is capable of connecting a signal line.

6. The partial discharge sensing device according to claim 5, wherein: The partial discharge sensing device is installed in the oil drain valve of the transformer.

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