WO2007097491A1

WO2007097491A1 - Partial discharge detecting device of gas insulated switchgear

Info

Publication number: WO2007097491A1
Application number: PCT/KR2006/001271
Authority: WO
Inventors: Ja Yoon Koo; Seung Yung Jung; Yonng Hong Kim; Cheol Hwi Ryu; In Jin Seo
Original assignee: Ja Yoon Koo; Seung Yung Jung; Yonng Hong Kim; Cheol Hwi Ryu; In Jin Seo
Priority date: 2006-02-22
Filing date: 2006-04-06
Publication date: 2007-08-30
Also published as: KR20070084971A; KR100757075B1

Abstract

Disclosed herein is a partial discharge detecting device, which is installed in a recess formed in a spacer of a gas insulated switchgear. The partial discharge detecting device of the gas insulated switchgear includes a spacer of the gas insulated switchgear, and a partial discharge detecting unit for detecting a partial discharge signal generated in the gas insulated switchgear. The partial discharge detecting unit is installed in a recess formed in the spacer.

Description

PARTIAL DISCHARGE DETECTING DEVICE OF GAS INSULATED SWITCHGEAR

Technical Field

[1] The present invention relates, in general, to a partial discharge detecting device of a gas insulated switchgear (GIS) and, more particularly, to a partial discharge detecting device, which is installed in a recess formed in a spacer of a gas insulated switchgear. Background Art

[2] A gas insulated switchgear is a complex switching device which opens or closes an electric circuit under normal conditions when used in indoor and outdoor substations, and safely opens or closes a line even under abnormal conditions, such as in the event of an accident or a short circuit, thus protecting a system, and which is insulated with Sulfur Hexafluoride (SF6) gas.

[3] Generally, the gas insulated switchgear is constructed so that switching equipment, such as a disconnection switch (DS), an earth switchgear (ES), or a circuit breaker (CB), are installed along with buses in a metallic enclosure which is filled with SF6 gas.

[4] A spacer is an insulator which supports a conductor in the metallic enclosure and provides a space for the insulating gas (SF6). The spacer must be made of a material which withstands a high electric field, changes little in electrical and mechanical properties in the presence of the decomposition product of the insulating gas, and is resistant to mechanical stress.

[5] Recently, in order to diagnose problems with gas insulated switchgears, an ultra- high-frequency (UHF) partial discharge detecting sensor has been used in various gas insulated switchgears.

[6] Generally, in the gas insulated switchgear system, a spacer, coupling cylindrical metallic enclosures with each other at predetermined intervals, is made of an insulating material, such as epoxy. Thus, when partial discharge occurs in the gas insulated switchgear, UHF partial discharge electromagnetic waves leak through the spacer to the outside. In order to take advantage of this, a partial discharge detecting sensor is attached to the outer portion of the spacer, thus detecting electromagnetic waves which are generated in the gas insulated switchgear, and removing noise from the detected signal, therefore diagnosing whether the gas insulated switchgear has a problem, such as degradation, and estimating the repair or replacement period.

[7] Most conventional partial discharge detecting sensors are mounted to the outer surface of the spacer. However, in order to enhance the detection sensitivity, a sensor which is not mounted to the outer surface of the spacer but is installed in the spacer is required.

Disclosure of Invention

Technical Problem

[8] Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a partial discharge detecting device, in which a partial discharge detecting sensor is installed in a spacer, thus enhancing the sensitivity of detection of partial discharge. Technical Solution

[9] In order to accomplish the object, the present invention provides a partial discharge detecting device of a gas insulated switchgear, including a spacer of the gas insulated switchgear; and a partial discharge detecting unit for detecting a partial discharge si gnal generated in the gas insulated switchgear, wherein the partial discharge detecting unit is installed in a recess formed in the spacer.

Advantageous Effects

[10] According to the present invention, a partial discharge detecting device is installed in a recess which is formed in a spacer of a gas insulated switchgear, thus enhancing the sensitivity of detection of partial discharge.

Brief Description of the Drawings [11] FIGS. 1 and 2 are views showing the state where a partial discharge detecting device according to an embodiment of the present invention is mounted to a gas insulated switchgear;

[12] FIGS. 3 to 6 are views showing embodiments of a partial discharge detecting unit;

[13] FIGS. 7 to 10 are views showing various embodiments of a partial discharge detecting unit; [14] FIG. 11 is a view showing the state where the partial discharge detecting unit of the gas insulated switchgear of FIG. 7 is installed in a recess which is formed in a spacer of the gas insulated switchgear;

[15] FIG. 12 is a view showing an embodiment of an antenna; and

[16] FIGS. 13 and 14 are views showing examples of the partial discharge detecting unit using the antenna of FIG. 12. [17] Reference now should be made to the drawings, in which the same reference numerals are used throughout the different drawings to designate the same or similar components.

[ 18] *Description of reference characters of important parts*

[19] 10 : gas insulated switchgear 100 : spacer

[20] 200 : body 300 : signal analyzer [21] 510, 510a : antenna 520, 520a, 520b : earth plate

[22] 521, 521c, 521d : coupling line 530 : connector

[23] 531 : core wire 532 : insulating sheath

[24] 533 : outer conductor 540 : insulator

Best Mode for Carrying Out the Invention [25] In order to accomplish the object, the present invention provides a partial discharge detecting device of a gas insulated switchgear, including a spacer of the gas insulated switchgear; and a partial discharge detecting unit for detecting a partial discharge signal generated in the gas insulated switchgear, wherein the partial discharge detecting unit is installed in a recess formed in the spacer. [26] According to an aspect of this invention, the recess is formed in an outer surface of the spacer. [27] In another aspect of this embodiment, the partial discharge detecting unit includes an antenna; and an earth plate installed adjacent to the antenna. [28] In yet another aspect of this embodiment, the antenna has a shape of a cylindrical spring. [29] In still another aspect of this embodiment, a height of the antenna is from 0.5cm to

1.5cm, and a diameter of a base of the antenna is from 0.3cm to 0.7cm. [30] In yet another aspect of this embodiment, the antenna has a shape of a prism having conductive lines which are longitudinally printed on an outer surface of the prism, the conductive lines being electrically coupled to each other at a predetermined position. [31] In still another aspect of this embodiment, the earth plate is an 'L' -shaped conductive plate, and the antenna is located at a corner of the earth plate, which is cut concavely. [32] In yet another aspect of this embodiment, the antenna is secured to the earth plate via an insulator, the antenna and the earth plate being electrically insulated from each other. [33] In still another aspect of this embodiment, the earth plate comprises a plurality of

L' -shaped conductive plates which are layered. [34] In yet another aspect of this embodiment, a surface of the spacer other than a surface having the recess is covered with a conductive plate. [35] In still another aspect of this embodiment, the partial discharge detecting unit further includes a connector, which is electrically connected to the earth plate and connects the antenna and the earth plate of the partial discharge detecting unit to signal lines connected to a signal analyzer, the connector including an outer conductor electrically secured to the earth plate; a core wire electrically coupled to the antenna; and an insulating sheath electrically insulating the core wire and the outer conductor from each other.

[36] In yet another aspect of this embodiment, the earth plate is a rectangular conductive plate, and the antenna is set up on an upper surface of the earth plate.

[37] In still another aspect of this embodiment, the earth plate comprises a plurality of rectangular conductive plates which are layered.

[38] In yet another aspect of this embodiment, the earth plate is a circular conductive plate, and the antenna is set up on the earth plate.

[39] In still another aspect of this embodiment, the earth plate comprises a plurality of circular conductive plates which are stacked.

[40] Hereinafter, the preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[41] FIGS. 1 and 2 are views showing the state where a partial discharge detecting devic e according to an embodiment of the present invention is mounted to a gas insulated switchgear, and FIGS. 3 to 6 are views showing embodiments of a partial discharge detecting unit.

[42] According to the present invention, the partial discharge detecting device of the gas insulated switchgear is characterized in that it is installed in a recess 110 which is formed in a spacer 100 of the gas insulated switchgear 10. Referring to FIGS. 1 and 2, the gas insulated switchgear 10 includes bodies 200 and spacers 100 which are provided between the bodies 200. One recess or a plurality of recesses 110 is formed in each spacer 100. As necessary, the outer surface of the spacer, other than the surface having the recess, may be covered with a conductive plate.

[43] A partial discharge detecting unit 500 having an antenna is installed in the recess

110 of the spacer of the gas insulated switchgear.

[44] In consideration of the size of the spacer of the gas insulated switchgear, only a small recess is formed in the spacer. Thus, the partial discharge detecting unit is manufactured to have a small size.

[45] The partial discharge detecting unit 500 includes an antenna 510 and an earth plate

520. Referring to FIG. 3, the antenna 510 has a helical shape, and the overall profile of the antenna is cylindrical. The earth plate 520 is an L' -shaped conductive plate. The antenna 510 is located at an L'-shaped corner of the earth plate, that is, a concave part 529 of the earth plate.

[46] The antenna 510 and the earth plate 520 are electrically insulated from each other.

[47] Referring to FIG. 4, the antenna 510 is secured to the earth plate 520 via an insulator 540. Signal lines 501 and 502 connected to a signal analyzer 300 are connected to the earth plate 520 and the antenna 510, respectively.

[48] The height of the antenna 510 is from about 0.5cm to 1.5cm, and the diameter of the base plane of the antenna 510 is from about 0.3cm to 0.7cm. [49] Referring to FIG. 5, a connector 530 is attached to the earth plate 520 so as to connect the antenna 510 and the earth plate 520 to the signal analyzer 300.

[50] The connector 530 includes a core wire 531, which is a conducting wire, an outer conductor 533, and an insulating sheath 532 which functions to electrically isolate the core wire 531 and the outer conductor 533 from each other.

[51] The outer conductor 533 is electrically connected to the earth plate 520 through soldering or a similar process. The core wire 531 is electrically coupled to the antenna 510.

[52] Since the signal lines 501 and 502 are connected to the core wire 531 and the outer conductor 533, respectively, the signal detected by the antenna 510 is transmitted to the signal analyzer 300.

[53] FIG. 6 shows an earth plate 520a, comprising several conductive plates which are layered. As shown in FIG. 6, when the earth plate 520a comprises several conductive plates which are layered, insulating materials are inserted or applied between the conductive plates, so that the neighboring plates are electrically insulated from each other. The layered conductive plates are electrically coupled at predetermined portions thereof to each other via a conductor, such as a coupling line 521.

[54] FIGS. 1 and 2 show the state where the partial discharge detecting device according to the preferred embodiment of this invention is installed in the recess which is formed in the spacer. As shown in FIGS. 1 and 2, the antenna 510 of the partial discharge detecting unit 500 is installed to face the inner surface of the gas insulated switchgear, that is, to face the inner surface of the spacer 100. The L' -shaped earth plate is installed to cover the side surface and the upper surface of the antenna. Mode for the Invention

[55] FIGS. 7 to 10 are views showing various embodiments of a partial discharge detecting unit.

[56] Referring to FIG. 7, an earth plate 520b is a rectangular conductive plate, and an antenna 510 is set up on the earth plate 520b, which is the rectangular conductive plate, in the form of a cylinder. The construction of FIG. 8 is similar to that of FIG. 7. However, unlike the construction of FIG. 7, the earth plate 520c comprises a plurality of rectangular conductive plates which are layered, and the plates are electrically coupled to each other using a coupling line 521c.

[57] Referring to FIG. 9, an earth plate 52Oe is a circular conductive plate, and an antenna 510 is set up on the circular conductive plate in the form of a cylinder. The construction of FIG. 10 is similar to that of FIG. 9. However, unlike the construction of FIG. 9, the earth plate 52Od comprises a plurality of circular conductive plates which are layered. [58] FIG. 11 shows the state where the partial discharge detecting unit of the gas insulated switchgear of FIG. 7 is installed in the recess which is formed in the spacer of the gas insulated switchgear. As shown in FIG. 11, the earth plate of the partial discharge detecting unit is placed in the recess of the spacer, and the cylindrical antenna is set up on the earth plate.

[59] FIG. 12 is a view showing another embodiment of an antenna.

[60] Referring to FIG. 12, an antenna 510a is not a cylindrical helical antenna, but has the shape of a triangular prism. Conductive lines 511 are printed longitudinally on the surface of an insulator having the shape of a triangular prism. The conductive lines 511 converge on a coupling point 512, which is formed on the lower surface of the insulator having the shape of the triangular prism. A signal line connected to the signal analyzer 300 is connected to the coupling point.

[61] The height of the antenna 510a is from about 0.5cm to 1.5cm, and the length of the base of the antenna 510a is from about 0.3cm to 0.7cm.

[62] FIGS. 13 and 14 are views showing examples of the partial discharge detecting unit using the antenna of FIG. 12. The shape of the earth plate and the coupling form are equal to those of FIGS. 3 to 6, except the shape of the antenna, and thus a detailed description thereof is omitted.

[63] Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

[64] For example, the earth plate has been illustrated herein as being L-shaped, rectangular, or circular, but the earth plate may have a different shape, as long as the earth plate is coupled to the antenna and is installed in the recess which is formed in the spacer. Industrial Applicability

[65] As described above, the present invention provides a partial discharge detecting device of a gas insulated switchgear, in which a partial discharge detecting sensor is installed in a spacer, thus enhancing the sensitivity of detection of partial discharge, and which can be variously applied to a switching device for high voltage.

[66]

Claims

[I] A partial discharge detecting device of a gas insulated switchgear, comprising: a spacer of the gas insulated switchgear; and a partial discharge detecting unit for detecting a partial discharge signal generate d in the gas insulated switchgear, wherein the partial discharge detecting unit is installed in a recess formed in the spacer. [2] The partial discharge detecting device according to claim 1, wherein the recess is formed in an outer surface of the spacer. [3] The partial discharge detecting device according to claim 1 or 2, wherein the partial discharge detecting unit comprises: an antenna; and an earth plate installed adjacent to the antenna. [4] The partial discharge detecting device according to claim 3, wherein the antenna has a shape of a cylindrical spring. [5] The partial discharge detecting device according to claim 4, wherein a height of the antenna is from 0.5cm to 1.5cm, and a diameter of a base of the antenna is from 0.3cm to 0.7cm. [6] The partial discharge detecting device according to claim 3, wherein the antenna has a shape of a prism having conductive lines which are longitudinally printed on an outer surface of the prism, the conductive lines being electrically coupled to each other at a predetermined position. [7] The partial discharge detecting device according to claim 6, wherein a height of the antenna ranges from 0.5cm to 1.5cm, and a maximum length of a base of the antenna ranges from 0.3cm to 0.7cm. [8] The partial discharge detecting device according to any one of claims 4 to 7, wherein the earth plate is an 'L' -shaped conductive plate, and the antenna is located at a corner of the earth plate, which is cut concavely. [9] The partial discharge detecting device according to claim 8, wherein the antenna is secured to the earth plate via an insulator, the antenna and the earth plate being electrically insulated from each other. [10] The partial discharge detecting device according to claim 9, wherein the earth plate comprises a plurality of 'L' -shaped conductive plates which are layered.

[I I] The partial discharge detecting device according to claim 8, wherein a surface of the spacer other than a surface having the recess is covered with a conductive plate.

[12] The partial discharge detecting device according to claim 8, wherein the partial discharge detecting unit further comprises a connector, which is electrically connected to the earth plate and connects the antenna and the earth plate of the partial discharge detecting unit to signal lines connected to a signal analyzer, the connector comprising: an outer conductor electrically secured to the earth plate; a core wire electrically coupled to the antenna; and an insulating sheath electrically insulating the core wire and the outer conductor from each other. [13] The partial discharge detecting device according to any one of claims 4 to 7, wherein the earth plate is a rectangular conductive plate, and the antenna is set up on an upper surface of the earth plate. [14] The partial discharge detecting device according to claim 13, wherein the antenna and the earth plate are secured to each other via an insulator, and the ant enna and the earth plate are electrically insulated from each other. [15] The partial discharge detecting device according to claim 14, wherein the earth plate comprises a plurality of rectangular conductive plates which are layered. [16] The partial discharge detecting device according to claim 13, wherein a surface of the spacer other than a surface having the recess is covered with a conductive plate. [17] The partial discharge detecting device according to claim 13, wherein the partial discharge detecting unit further comprises a connector, which is electrically connected to the earth plate and connects the antenna and the earth plate of the partial discharge detecting unit to signal lines connected to a signal analyzer, the connector comprising: an outer conductor electrically secured to the earth plate; a core wire electrically coupled to the antenna; and an insulating sheath electrically insulating the core wire and the outer conductor from each other. [18] The partial discharge detecting device according to any one of claims 4 to 7, wherein the earth plate is a circular conductive plate, and the antenna is set up on an upper surface of the earth plate. [19] The partial discharge detecting device according to claim 18, wherein the antenna and the earth plate are secured to each other via an insulator, and the antenna and the earth plate are electrically insulated from each other. [20] The partial discharge detecting device according to claim 19, wherein the earth plate comprises a plurality of circular conductive plates which are layered. [21] The partial discharge detecting device according to claim 18, wherein a surface of the spacer other than a surface having the recess is covered with a conductive plate. [22] The partial discharge detecting device according to claim 18, wherein the partial discharge detecting unit further comprises a connector, which is electrically connected to the earth plate and connects the antenna and the earth plate of the partial discharge detecting unit to signal lines connected to a signal analyzer, the connector comprising: an outer conductor electrically secured to the earth plate; a core wire electrically coupled to the antenna; and an insulating sheath electrically insulating the core wire and the outer conductor from each other.