JP2006047285A - Partial discharge sensor, partial discharge sensing device, and gas insulated electrical equipment with partial discharge sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a partial discharge sensor with simplification and weight-saving for its structure, and to provide gas insulated electrical equipment having the same. <P>SOLUTION: The gas insulated electrical equipment comprises the partial discharge sensor, a high-voltage conductor, supported by an insulating support in an insulated gas-filled metal container, and a gas-insulated bus equipped with a handhole section, containing a hollow placed in the metal container. This partial discharge sensor comprises composed of an insulating substrate, a conductive thin film integrally-combined with or adhered to the insulating substrate, a terminal electrically connected to the conductive thin film, a conductor electrically connecting the terminal with the conductive thin film, and a flange supporting the insulating substrate. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a sensor, a partial discharge detection device, and a gas insulated electrical device that detect partial discharge of a gas insulated electrical device that is used by sealing an insulating gas such as sulfur hexafluoride (SF6) gas in a metal container. In particular, the present invention relates to a gas-insulated electrical apparatus having a partial discharge detection function due to an insulation abnormality.

  A gas insulated switchgear, a gas insulated transformer, and the like, and a gas insulated bus have a structure in which a fixed / movable contact, a coil, a high-voltage conductor, and the like are insulated and supported in a metal container filled with an insulating gas such as SF6.

  These gas-insulated electrical devices generate partial discharges when a high electric field is applied due to internal abnormalities such as contamination of foreign matter in metal containers, protrusions present on high voltage conductors, or voids generated in the insulating support, Insulation characteristics may deteriorate, eventually resulting in dielectric breakdown. In order to prevent dielectric breakdown accidents of gas-insulated electrical equipment, it is necessary to accurately detect a partial discharge that can be said to be a precursor phenomenon of dielectric breakdown.

  One method for accurately detecting a partial discharge is to detect an electromagnetic wave generated due to the partial discharge. A well-known electromagnetic wave detection method is a method in which a metal detection electrode is installed in a hand hole inside a metal container, and electromagnetic waves are detected by this detection electrode (see, for example, Patent Documents 1 and 2).

  In this type of electromagnetic wave detection method, for example, a signal detected by a detection sensor is subjected to frequency analysis in a frequency band of several hundred MHz to several GHz by a spectrum analyzer, and a frequency-signal strength characteristic is measured. It is confirmed whether a partial discharge signal exists in a frequency band of several GHz. As another method, the signal detected by the detection sensor is passed through a band pass filter of several hundred MHz to several GHz, and then envelope detection is performed to detect the detected signal. From the voltage phase-signal strength characteristics, It is confirmed whether partial discharge has occurred.

JP-A-8-271574 (Summary) Japanese Patent No. 3299547 (Claim 1)

  In the electromagnetic wave detection method, a detection electrode is often installed in a device that generates a decomposition product due to decomposition of SF6, such as a gas-insulated bus or a gas-insulated circuit breaker that generates a large vibration during operation. In such a case, as described in Patent Document 1, since the conventional detection electrode is generally formed of a metal plate such as stainless steel or aluminum, the plate thickness is increased in order to ensure mechanical strength to withstand vibration. However, as the plate thickness increases, the weight increases, and the support structure for supporting this increases in size, resulting in an increase in the size of the sensor. In addition, the number of parts for fixing the detection electrode inevitably increases, and there is a possibility that the performance may vary due to dimensional tolerances.

  An object of the present invention is to reduce the number of parts for constituting a sensor, and to reduce the size and weight of a partial discharge detection sensor, a partial discharge detection device, and a gas-insulated electric apparatus.

  The present invention relates to an insulating substrate, a conductive thin film integrated by bonding or bonding to the insulating substrate, a terminal electrically connected to the conductive thin film, and electrically connecting the terminal and the conductive thin film. The present invention provides a partial discharge detection sensor comprising a conductor to be electrically connected and a support member for supporting the insulating substrate.

  The present invention also relates to an insulating substrate, a conductive thin film bonded to and bonded to the surface of the insulating substrate, a supporting means for supporting the insulating substrate, a flange for combining the supporting means, An electrical signal transmitted by the coaxial cable, comprising: a terminal for transmitting an electrical signal received by the thin film; a coaxial cable for transmitting the terminal and the signal; and a connector for connecting the coaxial cable and the terminal. A partial discharge detection device comprising a measuring instrument for measuring the above is provided.

  Furthermore, the present invention provides a gas-insulated bus comprising a high-voltage conductor supported by an insulating support in a metal container filled with an insulating gas, and a handhole portion having a recess disposed in the metal container, A gas-insulated electrical device electrically connected to the bus bar and a sensor for detecting harmonic electromagnetic waves installed in the depression, the sensor being integrated by bonding or bonding to one or both sides of the insulating substrate The present invention provides a gas-insulated electric apparatus comprising: a thin film; a terminal electrically connected to the conductive thin film; and means for fixing the insulating substrate to a flange of a handhole portion.

  According to the present invention, the detection electrode can be reduced in weight as compared with the conventional metal plate electrode, and the number of parts to which the sensor electrode is attached can be reduced.

  In the present invention, the gas-insulated electrical apparatus includes one or more gas-insulated buses and one or more gas-insulated electrical devices such as a gas circuit breaker, a gas insulation disconnector, a gas insulation transformer, and the like. GIS (such as gas insulated switchgear). In addition, the gas insulated electrical equipment of this invention points out the thing which provided the partial discharge detection sensor in the hollow of the hand hole part of the gas insulated electrical apparatus and the said gas insulated bus. Further, the partial discharge detection sensor may be always connected to a coaxial cable, or may be connected via a connector only when necessary. The coaxial cable transmits a voltage induced by an electromagnetic wave detected by a conductive thin film to a measuring device via an amplifier.

  In the present invention, the partial discharge detection device includes an insulating substrate, a conductive thin film bonded to and bonded to the substrate, a terminal electrically connected to the conductive thin film, and the insulating substrate. A partial discharge detection sensor having a flange for supporting the terminal, and a coaxial cable connected to the terminal via a connector.

  In the present invention, the partial discharge detection sensor is electrically coupled to the insulating substrate, the conductive thin film integrated by bonding or bonding to the substrate, and the conductive thin film as described above. And a support member for supporting the insulating substrate.

  The conductive thin film of the sensor preferably has a thickness of 5 to 500 μm, particularly 10 to 50 μm. The conductive thin film is preferably a vacuum-deposited metal thin film, a thin film coated with a conductive paint, or a metal foil. Particularly, the metal foil is bonded to an adhesive substrate from the viewpoint of ease of manufacturing, cost, dimensional accuracy, and the like. Is preferred. It is desirable that the conductive thin film is covered with a protective layer to protect the thin film from corrosion caused by gas decomposable organisms and moisture.

  A connector for electrically connecting the terminal and the coaxial cable can be provided. The coaxial cable and the measuring device for measuring the voltage induced by the electromagnetic wave may be always connected, or may be connected only when measuring the presence or absence of partial discharge.

  Two conductive thin films may be formed on one side of the insulating substrate, or one conductive thin film may be formed on both sides of the insulating substrate. When two conductive thin films are formed, one conductive thin film is connected to the core wire of the coaxial cable, and the other conductive thin film is connected to a sheath wire of the coaxial cable.

  Conductive thin films are respectively formed on the front and back surfaces of the insulating plate, one conductive thin film is connected to a core wire of the coaxial cable, and the other conductive thin film is connected to a sheath wire of the coaxial cable.

  Two conductive thin films are formed on the surface of the insulating substrate, one conductive thin film is connected to a core wire of the coaxial cable, and the other conductive thin film is connected to a sheath wire of the coaxial cable.

  One of the two conductive thin films is formed on the surface of the insulating substrate, the other is formed on the back surface of the insulating substrate, one conductive thin film is connected to the core wire of the coaxial cable, and the other conductive film is formed. A conductive thin film is connected to the outer sheath wire of the coaxial cable. The above configuration can also be adopted in the partial discharge detection sensor. One of the two conductive thin films is formed on the surface of the insulating substrate, and the other is formed on the back surface of the insulating substrate.

  The material of the insulating substrate can be arbitrarily selected as long as it is insulating and has an ordinary mechanical strength and corrosion resistance to the decomposition product of SF6 gas. Examples thereof include thermoplastic resins such as polyolefin and polycarbonate, thermosetting resins such as epoxy resins and unsaturated polyester resins, fiber reinforced plastics, and laminates. Ceramics such as alumina and zirconia can also be used, but since ceramics are porous, they contain air after firing and may release air in a gas-insulated atmosphere. An insulating substrate of the system is preferable. A metal pattern having a predetermined shape can be formed by an etching technique on a product obtained by pressure laminating a metal foil such as a copper foil with an adhesive on one or both sides of a resin laminate. Whether it is a vacuum deposition technique or a conductive coating method, an electrode pattern with high dimensional accuracy can be easily manufactured together with the etching technique. The thickness of the insulating substrate is not particularly limited as long as the conductive thin film can be supported smoothly. For example, the thickness may be about 1 to 10 mm.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 9 shows a specific configuration of FIG. 2 of Patent Document 2. The metal electrode plate 20 is fixed to the insulating support 27 by bolts 21 (actually fixed by four or more). Further, the insulating support 27 is fixed to the flange 24 with bolts 22 (which is also actually required four or more). In addition, the edge part of the metal plate electrode plate 20 attaches R to the corner | angular part 25 in order to prevent discharge. Thus, when the processing of the electrode corners and the machining of the metal electrode plate 20 are taken into consideration, a thickness of several mm is required. Therefore, the metal electrode plate 20 must be fixed with a large number of bolts as shown in the figure.

  Also in Patent Document 1, the conductive disk of the partial discharge detection device has a thickness of several millimeters, for example, 2 mm. Therefore, although it is not described in Patent Document 1, it is actually the same as Patent Document 2. In this case, it is considered necessary to fix the disk to the conductive support with a plurality of bolts.

  Since the electrode of the sensor according to the present invention is a thin film, it can be integrated by, for example, vapor deposition, metal foil lamination, or application of a conductive paint, and by integrating, bonding, bonding or adhering to an insulating substrate. Fixing means such as bolts are not required, and there are significant practical effects such as reduction in the number of parts and reduction in weight and structure.

  By using printed circuit board manufacturing technology, copper foil or the like is bonded to one or both sides of an insulating substrate with an adhesive, and this metal thin film is patterned into a predetermined shape by etching technology, so that it is inexpensive and has dimensional accuracy. A good electrode film can be formed.

  FIG. 1 is a partial cross-sectional schematic view of a gas-insulated electrical apparatus including a gas-insulated bus A having a detection electrode for detecting an insulation abnormality inside a metal container and a gas-insulated electrical device 28 such as a gas-insulated circuit breaker. It is. FIG. 3 is a cross-sectional view of the gas-insulated electrical apparatus of FIG. 1 as viewed from the side. Although the measuring instrument is omitted in FIG. 1, the measuring instrument 20 is shown in FIG. The measuring device 20 may incorporate an amplifier 29.

  FIG. 2 is an enlarged view of the partial discharge detection sensor. On the insulating substrate 12, two metal thin films 11 are bonded or bonded to the insulating substrate 12 by vapor deposition, coating, or etching, and are integrated with each other. The screws 13 are screwed into the conductor 7 to fix the insulating substrate 12. The conductor 7 is electrically connected to the terminal 6, and the terminal portion is fixed to the flange (lid) 5 of the handhole portion. If necessary, the support structure of the insulating substrate 12 may be reinforced by providing one or more supports 14. The support 14 may be a conductor, and in this case, the support 14 is electrically connected to the metal thin film 11. And you may connect with the core wire or outer sheath wire of a coaxial cable mentioned later. In the present invention, the partial discharge detection device means a device provided with a coaxial cable and a connector for connecting the coaxial cable and a terminal in addition to the sensor shown in FIG.

  The embodiment of FIGS. 1 and 3 shows a case where an insulation abnormality detecting device is applied to one phase of a gas insulated bus which is a gas insulated electrical device. The metal container 1 in this embodiment is tubular and is at ground potential. An insulating gas such as SF 6 is sealed inside the metal container 1, and the high voltage conductor 2 is insulated and supported in the metal container by an insulating support 3 formed of an insulating material such as epoxy resin. .

  The metal container 1 is provided with a hand hole 4 in which a detection sensor including the detection electrode 10 in the insulation abnormality detection device is provided. The detection sensor includes a detection electrode 10, a conductor 7 that transmits a signal received by the detection electrode 10, and a sealed terminal 6 that passes through a cover plate (flange) 5 of the handhole 4.

  As shown in FIG. 2, the detection electrode 10 is configured by forming two metal thin films 11 in an electrode pattern shape on the surface of an insulating substrate 12. The detection electrode 10 can be made, for example, by etching a printed board to form an electrode pattern. In addition, the metal thin film 11 can be formed by vapor deposition on the insulating substrate 12, and can also be formed by applying a conductive paint to the insulating substrate 12 in the electrode pattern shape. When a printed board is used, the electrode pattern can be formed with high accuracy. In addition, when the electrode pattern is formed by vapor deposition, there is almost no variation in the detection sensitivity of each sensor, so that it is possible to simplify quality control at the time of component manufacture.

  The material of the metal thin film 11 is preferably copper or aluminum having good electrical conductivity, and the film thickness is preferably 5 to 500 μm, particularly preferably 20 to 30 μm, and it is desirable that the thickness does not exceed 1000 μm. In the case of a conventional metal electrode plate, the thickness is usually 2 to 3 mm, so that it is remarkably thinned and lightened by the present invention.

  When the electrode pattern is formed on the insulating substrate 12 to form the detection electrode 10 as in the present embodiment, the weight is greatly reduced, so that the electrode support structure can be significantly simplified. . For example, as shown in FIG. 2, it is sufficient to fix the insulating substrate 12 to the conductor 7 with screws 13. In order to support the detection 10 electrode more stably, a cylindrical electrode support 14 made of an insulating material may be provided. The detection electrode 10 may be fixed to the conductor 7 by soldering without using a screw.

When a metal electrode plate having a thickness of several mm is used as in the prior art, a large support body or a large antenna support is used to support the plate-like electrode. The support structure will be greatly simplified. According to the present invention, the number of parts can be greatly reduced as compared with the conventional electrode structure. Further, according to the present invention, it is possible to reduce variations in detection sensitivity of individual sensors, which have conventionally been caused by manufacturing tolerances of metal plates and dimensional errors due to electrode attachment. In addition to the above effects, the detection sensor can be reduced in size and weight, and as a result, the detection sensor can be manufactured at low cost.

  As described above, the detection electrode 10 is electrically connected to the conductor 7 connected to the sealing terminal 6 that passes through the cover plate (flange) 5 of the handhole 4. Further, the sealing terminal 6 is further connected to a connector 8, the connector 8 is electrically connected to a coaxial cable 9, and the coaxial cable 9 is connected to a measuring instrument 20. The detection electrode 10 is electrically insulated from the metal container 1. The detection sensor, the connector 8, the coaxial cable 9, and the measuring instrument 20 constitute the insulation abnormality detection device of the present invention.

  The detection sensor of the present invention is not limited to the case where it is used by being installed in the hand hole 4 inside the gas-insulated electric device as in the present embodiment. Can be deployed and used.

  As shown in FIG. 4, the shape of the detection electrode 10 may be one in which a metal thin film 11a, 11b is vapor-deposited on a circular insulating substrate, or a conductive film is formed into a disk shape, or FIG. As shown in FIG. 5, a rectangular insulating substrate 12 may be formed with circular metal thin films 11 a and 11 b.

  When the detection sensor according to the present invention is used in a switch such as a circuit breaker or a disconnect switch, the detection electrode 10 may be corroded by the decomposed gas generated by the decomposition of the insulating gas such as SF6, and the performance may be deteriorated. . In such a case, a protective layer 15 may be provided on the surface of the metal thin film 11 as shown in FIG. The protective layer 15 can be formed by coating an insulating material or by providing a thin plate made of an insulating material.

  When partial discharge occurs in the metal container 1, a high-frequency current pulse of several GHz is generated, and electromagnetic waves propagate through the metal container 1. When the propagated electromagnetic wave is received by the metal thin film 11 which is an antenna receiving unit, a voltage is induced in the metal thin film 11. The induced voltage is taken out of the metal container 1 through the conductor 7 and the sealing terminal 6 and transmitted to the measuring device 20 through the coaxial cable 9. By transmitting a signal with a coaxial structure from the antenna receiver, it is possible to transmit the received signal of 1000 MHz or more to the measuring device 20 without attenuation.

  As shown in FIGS. 7 and 8, the antenna characteristics can be further improved by using the detection electrode 10 having a plurality of metal thin films 11a and 11b that are not electrically connected. In this case, the metal thin film 11a on which one electrode pattern is formed is electrically connected to the core wire 16 of the coaxial cable 9, and the other metal thin film 11b is electrically connected to the sheath wire 17 of the coaxial cable 9. It becomes. If the metal thin film in which the electrode pattern is formed as shown in FIG. 8 is formed on both surfaces of the insulating substrate 12, the insulation performance between the electrodes and the detection sensitivity can be further improved. Moreover, it is also possible to set it as the electrode which electrically connected both surfaces. In the coaxial cable, the core wire and the outer sheath wire are covered with an insulating material.

  According to the present invention, it is possible to improve the dimensional accuracy of the detection electrode, and in addition to the partial discharge measurement by electromagnetic waves, the detection electrode can be used to detect a decrease in insulation performance of the gas-insulated electrical apparatus. In gas-insulated electrical equipment, the insulation performance is reduced due to the moisture content of the insulating gas or the decomposition products of the insulating gas. In the case of a conventional metal electrode plate, electrical characteristics between detection electrodes, such as insulation resistance, may vary from sensor to sensor, and it is difficult to measure with high accuracy. I couldn't. Therefore, conventionally, a small amount of insulating gas sealed in gas-insulated electrical equipment is taken out and a specific component is chemically measured, or the moisture content in the gas is measured by a moisture measuring device or a dew point meter. . According to the present invention, since a detection electrode with high dimensional accuracy can be easily manufactured, it can be used for measurement of insulation performance degradation. The measurement of the insulation performance degradation according to the present invention is performed, for example, by applying a DC voltage to the two detection electrodes in FIG. 7 and measuring the leakage current flowing between the detection electrodes.

  As described above, according to the present invention, it is possible to monitor two insulation abnormalities such as measurement of partial discharge by electromagnetic wave measurement and deterioration of insulation performance caused by the amount of moisture in the insulating gas, etc. by one sensor.

The front view of the gas insulation electric equipment containing a partial discharge detection apparatus. Sectional drawing of the detection sensor in FIG. The figure which looked at the gas insulation electric equipment shown in Drawing 1 from the side. The perspective view which shows the shape of the detection electrode by one Example of this invention. The perspective view which shows the shape of the detection electrode by other Examples of this invention. Sectional drawing which shows the other Example of a detection electrode. Sectional drawing which shows the structural example at the time of providing the detection electrode which has a some metal thin film. Sectional drawing which shows the structural example at the time of providing the detection electrode which has a metal thin film on both surfaces of an insulating board | substrate. Sectional drawing for demonstrating the specific structure of the sensor of patent document 2. As shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Metal container, 2 ... High voltage conductor, 3 ... Insulation support body, 4 ... Hand hole, 5 ... Cover plate, 6 ... Sealing terminal, 7 ... Conductor, 8 ... Connector, 9 ... Coaxial cable, 10 ... Detection electrode, DESCRIPTION OF SYMBOLS 11 ... Metal thin film, 12 ... Insulating substrate, 13 ... Screw, 14 ... Electrode support, 15 ... Protective layer, 16 ... Core wire, 17 ... Outer wire, 20 ... Measuring instrument

Claims (17)

  Insulating substrate, conductive thin film bonded and bonded to insulating substrate, terminal electrically connected to the conductive thin film, and electrically connecting the terminal and the conductive thin film A partial discharge detection sensor comprising: a conductive conductor; and a support member that supports the insulating substrate.   The partial discharge detection sensor according to claim 1, wherein two conductive thin films are formed on a surface of the insulating substrate.   3. The partial discharge detection sensor according to claim 2, wherein one of the two conductive thin films is formed on the surface of the insulating substrate, and the other is formed on the back surface of the insulating substrate.   An insulating substrate, a conductive thin film bonded and bonded to the surface of the insulating substrate, a supporting means for supporting the insulating substrate, a flange coupled to the supporting means, and an electric power received by the conductive thin film A partial discharge detection device comprising: a terminal that transmits a signal; a coaxial cable that transmits the signal to the terminal; and a connector that connects the coaxial cable and the terminal.   5. The partial discharge detection device according to claim 4, further comprising a measuring device for measuring an electric signal transmitted by the coaxial cable.   Two conductive thin films are formed on the surface of the insulating substrate, one conductive thin film is connected to a core wire of the coaxial cable, and the other conductive thin film is connected to a sheath wire of the coaxial cable. The partial discharge detection device according to claim 4, wherein   One of the two conductive thin films is formed on the surface of the insulating substrate, the other is formed on the back surface of the insulating substrate, one conductive thin film is connected to the core wire of the coaxial cable, and the other conductive film is formed. The partial discharge detecting device according to claim 6, wherein a conductive thin film is connected to an outer sheath wire of the coaxial cable. A high voltage conductor supported by an insulating support in a metal container filled with an insulating gas, a gas insulated bus provided in the metal container and having a handhole portion having a depression;
A gas insulated electrical device in electrical communication with the bus;
A sensor installed in the depression to detect harmonic electromagnetic waves,
The sensor comprises a conductive thin film integrated by bonding or bonding to one or both sides of an insulating substrate;
A terminal electrically connected to the conductive thin film;
Means for fixing the insulating substrate to the flange of the handhole portion;
A gas-insulated electrical apparatus comprising:   The gas-insulated electric apparatus according to claim 8, wherein the conductive thin film of the sensor has a thickness of 5 to 500 µm.   The gas-insulated electrical apparatus according to claim 8, wherein the conductive thin film is a vacuum-deposited metal thin film.   The gas-insulated electrical device according to claim 8, wherein the conductive thin film is a thin film coated with a conductive paint.   The gas-insulated electrical device according to claim 8, wherein the conductive thin film is a metal foil.   The gas-insulated electrical apparatus according to claim 8, wherein the conductive thin film is covered with a protective layer.   The gas-insulated electrical apparatus according to claim 8, further comprising a connector that electrically connects the terminal and the coaxial cable.   The gas-insulated electrical apparatus according to claim 8, wherein two conductive thin films are formed on one side of the insulating substrate.   9. The gas-insulated electrical apparatus according to claim 8, wherein one conductive thin film is connected to a core wire of a coaxial cable, and the other conductive thin film is connected to a sheath wire of the coaxial cable.   Conductive thin films are respectively formed on the front and back surfaces of the insulating substrate, one conductive thin film is connected to a core wire of a coaxial cable, and the other conductive thin film is connected to a sheath wire of the coaxial cable. The gas-insulated electrical apparatus according to claim 8.

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