JP2010054360A - Insulation diagnostic device for electric apparatus - Google Patents

Abstract

An insulation abnormality of an electric device including a metal container and a power device tank having an internal metal body for applying a high voltage in the metal container can be detected with high sensitivity in a space-saving and low-cost manner. A new insulation diagnostic device is provided.
An insulation diagnosis device for an electric device including a metal container and a power equipment tank having an internal metal body for applying a high voltage in the metal container, wherein the insulation diagnosis device is disposed in the power equipment tank. One end of the arranged insulator is projected to the outside of the power equipment tank, and the slit of the insulation diagnostic device is opened in a slit opened upward of a flange provided so as to fasten the projecting portion of the insulator. The outer frame is inserted and fixed.
[Selection] Figure 1

Description

  The present invention relates to an insulation diagnostic apparatus used for electrical equipment, and more particularly to an insulation diagnostic apparatus for electrically detecting an insulation abnormality inside an electrical equipment.

In order to quickly identify insulation abnormalities in SF ₆ gas insulated switchgears, transformers, lightning arresters, and other power equipment used in substations to contribute to power supply Insulation diagnostic devices that detect partial discharges that occur in the event of an insulation failure have been developed. Since the partial discharge mainly generates a high frequency electromagnetic wave of several tens of MHz to several GHz, it is necessary to provide a detection electrode (antenna) corresponding to the high frequency electromagnetic wave in order to detect the partial discharge.

  In constructing the insulation diagnostic apparatus as described above, various devices are made in the arrangement configuration of the detection electrode and the reference electrode (ground electrode) opposite to the detection electrode, the mutual electrode shape, and the like. Various studies have also been made on attachment methods, such as whether the insulation diagnostic device is externally attached to an electrical device or is incorporated and incorporated.

  However, regarding the installation of the insulation diagnostic device to the electrical equipment, it is necessary to prepare a space for installing the insulation diagnostic device, and the layout space of the electrical equipment including the insulation diagnostic device is enlarged. Therefore, in the present situation, the type in which the insulation diagnostic apparatus is incorporated into the electric device is more popular than the external attachment of the insulation diagnostic apparatus.

  For example, in Patent Document 1, an external electrode and an internal electrode are formed in a conical shape through metal bolts in an opening formed on the outer peripheral surface of a power equipment tank, and the diameter ratio of these electrodes is obtained from the opening. It is disclosed to provide a so-called flat plate type detection electrode, that is, an insulation diagnostic device, which is constant until the outlet.

  However, in the above-described configuration, when a flat plate type detection electrode is installed in a one-phase power equipment tank, and when a similar detection electrode is installed in another phase power equipment tank, from the viewpoint of preventing mutual interference. , You must take a large distance between each other. Although the separation distance itself is not large, when the number of power equipment tanks increases, a large space is required for laying out these power equipment tanks. As a result, a building or the like in which the power equipment tank is deployed becomes large, and a large area and space are required for installing the power equipment tank.

  Further, in Patent Document 2, a loop sensor is embedded in an electric power equipment tank via an insulating support, and a flat plate sensor is provided on the outer periphery of the electric power equipment tank, and is detected by the loop sensor and the flat plate sensor. Attempts have been made to detect an insulation abnormality of the power equipment tank based on the temporal variation and frequency response of the electromagnetic signal.

  However, the method described in Patent Document 2 does not cause problems such as installation space as described in Patent Document 1, but based on the difference in thermal expansion between the insulating support and the loop sensor, the loop In some cases, the state sensor peels off from the insulating support and does not function as an insulation diagnostic device.

Further, in the embedded insulation diagnostic apparatus described in Patent Document 2, there is a strong tendency to detect a large amount of corona in the air. If the filter is selected incorrectly or the state of the installed device is bad, the S / N The ratio may decrease.
JP 2002-5985 A JP 2003-185697 A

  INDUSTRIAL APPLICABILITY The present invention can detect an insulation abnormality of an electrical device including a metal container and a power device tank having an internal metal body that applies a high voltage in the metal container with high sensitivity at a small space and at a low cost. An object of the present invention is to provide a novel insulation diagnostic apparatus.

  One aspect of the present invention is an electrical equipment insulation diagnosis device including a metal container and a power equipment tank having an internal metal body that applies a high voltage to the metal container, and the insulation diagnosis apparatus includes the power equipment. One end of an insulator disposed in the tank protrudes to the outside of the power equipment tank, and the insulation is inserted into a slit opened upward of a flange provided to fasten the protruding portion of the insulator. The present invention relates to an insulation diagnostic device for electrical equipment, wherein the outer frame of the diagnostic device is fitted and fixed.

  According to the above aspect, the flange is provided so that one end of the insulator disposed in the power equipment tank protrudes outside the power equipment tank and the projecting portion of the insulator is fastened. A slit opened upward is provided, and the outer frame of the insulation diagnostic apparatus is fitted and disposed in this slit. Therefore, the electrical equipment (power equipment tank) and the insulation diagnostic device can be closely arranged as an external diagnostic device. As a result, discharge charges of several pC can be detected, and noise resistance can be improved.

  In this case, high-frequency electromagnetic waves of several tens of MHz to several GHz due to partial discharge based on the insulation abnormality occurring in the electric power equipment tank propagate in the electric power equipment tank, and the insulation diagnostic device ( It is detected by an external diagnostic device.

  On the other hand, since the insulation diagnostic device only needs to be attached to the flange attached to the power equipment tank, it can be attached to the power equipment tank in a space-saving and low-cost manner.

  Therefore, as described above, according to the insulation diagnostic device for electrical equipment of this aspect, a power equipment tank having a metal container and an internal metal body for applying a high voltage in the metal container at low cost and at a low cost. It is possible to provide a novel insulation diagnostic apparatus capable of detecting an insulation abnormality of an electric device including a high sensitivity.

  Hereinafter, other features and advantages of the present invention will be described.

(First embodiment)
FIG. 1 is a schematic configuration diagram showing an electrical equipment insulation diagnostic device according to the first embodiment, and FIG. 2 is an enlarged view showing the vicinity of a slit formed in a flange of the insulation diagnostic device shown in FIG. It is. FIG. 1 is a cross-sectional view of the insulation diagnostic apparatus including the electrical device when cut along the length direction of the electrical device and substantially the center line. In the present embodiment, as the electrical apparatus, SF ₆ gas or the like to the power equipment in the tank constituting the electrical device is shown for the case of encapsulated SF ₆ gas insulated switchgear.

  As shown in FIG. 1, when an insulation abnormality based on adhesion of an insulator or the like occurs, an electrical device that should detect partial discharge is a metal container 11 and an internal metal body that applies a high voltage to the metal container 11 12 is included. In addition to the power equipment tank 10, the electrical equipment can have various control systems and power supply systems depending on applications, but since it is not directly related to the upper air insulation diagnostic device of this aspect, And the description is omitted.

Further, as shown in FIG. 1, in the electric power equipment tank 10, rubber (insulator) 14 for sealing SF ₆ gas or the like enclosed in the tank is in close contact with the internal metal body 12, and the inside The metal body 12 is formed in a conical shape with the apex as an apex, and an end portion 14 </ b> A located on the bottom surface of the metal body 12 protrudes outside the power equipment tank 10. The protruding portion 14 </ b> A of the rubber 14 is fastened by a pair of studs 16 via a pair of flanges 15. Although not specifically shown in the figure, the flange 15 is formed over the entire outer periphery of the power equipment tank 10.

Incidentally, rubber 14 seals the SF ₆ gas or the like, if end if protrude outward of the power equipment tank 10, but is not limited to a conical shape as described above.

  In addition, a slit 15A is formed in each of the pair of flanges 15, and the outer frame 21 of the insulation diagnostic device 20 is fitted and fixed in these slits 15A. That is, the power equipment tank 10 and the insulation diagnostic device 20 can be closely arranged as an external diagnostic device. At this time, the contact resistance between the slit 15A and the outer frame 21 is set to about 1Ω or less.

  The insulation diagnostic device 20 is provided with a high-frequency receiver 22 at a substantially central portion of the upper side of the outer frame 21. However, a connector may be provided in place of the high frequency receiver 22 and connected to an external high frequency receiver (not shown) or the like.

  In this embodiment, when an insulation abnormality occurs in the power equipment tank 10 and the partial discharge d1 occurs, a high frequency electromagnetic wave L of several tens of MHz to several GHz is generated due to the partial discharge d1 and propagates in the power equipment tank 10. To do. Furthermore, it passes through the inside of the rubber 14 as an insulator, reaches the flange 15, and reaches the outer frame 21 of the insulation diagnostic device 20. Therefore, the power equipment tank 10 (electrical equipment) and the outer frame of the insulation diagnostic device 20, that is, the insulation diagnostic device 20 have the same potential. For this reason, it becomes difficult for noise to enter the insulation diagnostic apparatus 20.

  Further, as described above, since the power equipment tank 10 and the insulation diagnostic device 20 are arranged in close contact with each other, the high frequency electromagnetic wave L is difficult to leak outside through the gap between the insulation diagnostic device 20 and the power equipment tank 10. As a result, even if the high-frequency electromagnetic wave L is caused by a discharge charge of several pC, it can be detected and noise resistance can be improved.

  The high-frequency electromagnetic wave L is detected by the high-frequency receiver 22 described above or a high-frequency receiver provided separately outside.

  On the other hand, since the insulation diagnostic device 20 only needs to be attached to the flange 15 attached to the power equipment tank 10, it can be attached to the power equipment tank 10 with a small space and at a low cost.

  In this aspect, as shown in FIG. 2, the difference between the opening width of the slit 15A and the width of the outer frame 21 of the insulation diagnostic device 20 is preferably 1 mm or less. That is, as shown in FIG. 2, the sum of the distance w1 from the left wall of the slit 15A of the outer frame 21 and the distance w2 from the right wall (= w1 + w2) is 1 mm or less, so that the slit 15A and the insulation diagnosis are performed. Adhesiveness with the outer frame 21 of the apparatus 20 increases, and surface contact property improves. Therefore, the noise resistance described above can be further improved.

  Further, the surface roughness Ra of the slit 15A is preferably 0.25 μm or less. Even in this case, the adhesion between the slit 15A and the outer frame 21 of the insulation diagnostic device 20 is increased, and the surface contact is improved. Therefore, the noise resistance described above can be further improved.

  Furthermore, in this aspect, it is preferable to implement rust prevention coating with respect to the slit 15A. The electric equipment tank 10 (electric equipment) shown in FIG. 1 is not limited to the use inside a building, but can be used outdoors as needed. In this case, when rust is generated in the slit 15A, the contact resistance between the slit 15A and the outer frame 21 of the insulation diagnostic device 20 may increase, and noise resistance may deteriorate.

  On the other hand, as described above, the above disadvantage can be avoided by performing the antirust coating.

  Moreover, in this aspect, it is preferable to implement conductive grease coating on the slit 15A. By performing such conductive grease coating, the contact resistance between the slit 15A and the outer frame 21 of the insulation diagnostic device 20 can be reduced, and the outer frame 221 can be securely adhered and fixed to the slit 21A by the grease coating. Will be able to. Therefore, noise resistance can be improved.

(Second Embodiment)
FIG. 3 is a schematic configuration diagram illustrating an insulation diagnosis apparatus for an electrical device according to the second embodiment. FIG. 3 is a cross-sectional view of the insulation diagnostic apparatus including the electric device when cut along the line II in FIG. 1 in the length direction of the electric device.

This embodiment also shows a case of an SF ₆ gas insulated switchgear in which SF ₆ gas or the like is enclosed in a power equipment tank constituting the electrical equipment as the electrical equipment.

  In this embodiment, as shown in FIG. 3, the bottom surface 151A of the slit 15A is flattened. That is, the bottom surface 151 </ b> A of the slit 15 </ b> A is flattened instead of being arcuate according to the outer shape of the flange 15. In this case, the distance from the outer surface of the flange 15 to the bottom surface 151A varies depending on the measurement position, but since the bottom surface 151A of the slit 15A is flattened, the surface between the outer frame 21 of the insulation diagnostic device 20 and the slit 15A. The degree of contact can be improved.

  Therefore, the outer frame of the power equipment tank 10 (electric equipment) and the insulation diagnostic device 20, that is, the insulation diagnostic device 20 can be surely set to the same potential, and the high frequency electromagnetic wave L is generated from the insulation diagnostic device 20 and the power equipment tank. It becomes difficult to leak outside through a gap with 10. As a result, the noise resistance of the insulation diagnostic device 20 can be improved.

  In FIG. 3, reference numeral 15 </ b> B is a hole through which the stud 16 penetrates the flange 15.

  Also in this aspect, similarly to the first embodiment, the difference between the opening width of the slit 15A and the width of the outer frame 21 of the insulation diagnostic device 20 is preferably 1 mm or less. Furthermore, the surface roughness Ra of the slit 15A is preferably 0.25 μm or less. Moreover, in this aspect, it is preferable to implement antirust coating with respect to the slit 15A. Furthermore, it is preferable to perform conductive grease coating on the slit 15A.

(Third embodiment)
FIG. 4 is a schematic configuration diagram illustrating an insulation diagnosis apparatus for an electrical device according to a third embodiment. FIG. 4 is a cross-sectional view of the insulation diagnostic apparatus including the electric device when cut along the length direction of the electric device and substantially the center line.

This embodiment also shows a case of an SF ₆ gas insulated switchgear in which SF ₆ gas or the like is enclosed in a power equipment tank constituting the electrical equipment as the electrical equipment.

Also in this embodiment, the rubber (insulator) 14 such as SF ₆ gas sealed in the electric power equipment tank 10 is formed in a conical shape with the internal metal body 12 as a vertex, and the end portion 14A located on the bottom surface of the rubber 14 is an electric power equipment. It protrudes in the vertical direction outside the tank 10. And the protrusion part 14A of the up-down direction of the rubber | gum 14 is fastened by the pair of studs 16 via the pair of flanges 15, respectively.

  Further, slits 15A are formed in each of the pair of flanges 15 on the upper and lower sides of the electric power equipment tank 10, and the outer frame 21 of the insulation diagnostic device 20 is fitted and fixed in these slits 15A. In other words, the power equipment tank 10 and the insulation diagnostic device 20 are closely arranged as external diagnostic devices, and a total of two insulation diagnostic devices 20 are arranged.

  Note that, in any of the upper and lower flanges 15, the insulation diagnostic apparatus 20 is provided with a high-frequency receiver 22 at the substantially central portion of the upper side of the outer frame 21. However, a connector may be provided in place of the high frequency receiver 22 and connected to an external high frequency receiver (not shown) or the like.

  Further, in this aspect, the distance r1 from the end 14A of the rubber 14 of the slit 15A in the flange 15 positioned on the upper side of the power device tank 10 and the slit 15A in the flange 15 positioned on the lower side of the power device tank 10 are used. The distance r2 from the end 14A of the rubber 14 is different from each other.

  Therefore, in this embodiment, when an insulation abnormality occurs in the power equipment tank 10 and the partial discharge d1 occurs, a high frequency electromagnetic wave L of several tens of MHz to several GHz is generated due to the partial discharge d1, and the inside of the power equipment tank 10 , Passes through the inside of the rubber 14 as an insulator, reaches the flanges 15 positioned above and below the power equipment tank 10, and reaches the outer frame 21 of the insulation diagnostic device 20.

  In this case, in the upper and lower flanges 15, the distance r 1 from the end 14 A of the rubber 14 of the slit 15 A and the distance from the end 14 A of the rubber 14 of the slit 15 A in the flange 15 located on the lower side of the power equipment tank 10. Since they are different from r2, the detection outputs in the insulation diagnostic apparatuses 20 provided above and below the power equipment tank 10 are different from each other.

  For example, the detection output of the insulation diagnostic device 20 provided on the flange 15 located on the lower side of the power equipment tank 10 is compared with the detection output of the insulation diagnosis device 20 provided on the flange 15 located on the upper side of the power equipment tank 10. Becomes larger. That is, when an insulation abnormality occurs in the power equipment tank 10 and a partial discharge d1 occurs, detection outputs having different sizes can be obtained, so that the detection accuracy of the insulation abnormality in the power equipment tank 10 can be increased. .

  In the present embodiment, a total of two insulation diagnostic apparatuses 20 are provided above and below the electric power equipment tank 10 via the flange 15, but three or more insulation diagnosis apparatuses 20 may be provided as necessary.

  Also in this aspect, similarly to the first embodiment, the difference between the opening width of the slit 15A and the width of the outer frame 21 of the insulation diagnostic device 20 is preferably 1 mm or less. Furthermore, the surface roughness Ra of the slit 15A is preferably 0.25 μm or less. Moreover, in this aspect, it is preferable to implement antirust coating with respect to the slit 15A. Furthermore, it is preferable to perform conductive grease coating on the slit 15A.

  The present invention has been described in detail based on the above specific examples. However, the present invention is not limited to the above specific examples, and various modifications and changes can be made without departing from the scope of the present invention.

For example, in the above specific example, the rubber 14 for sealing SF ₆ gas or the like in the electric power equipment tank 10 is used as the insulator disposed in the electric power equipment tank 10 of the present invention. It can be arbitrarily configured according to the configuration and use of the power equipment tank 10.

It is a schematic block diagram which shows the insulation diagnostic apparatus of the electric equipment which concerns on 1st Embodiment. It is a figure which expands and shows the slit vicinity formed in the flange of the insulation diagnostic apparatus shown in FIG. It is a schematic block diagram which shows the insulation diagnostic apparatus of the electric equipment which concerns on 2nd Embodiment. It is a schematic block diagram which shows the insulation diagnostic apparatus of the electric equipment which concerns on 3rd Embodiment.

Explanation of symbols

10 Power Equipment Tank 11 Metal Container 12 Internal Metal Body 14 Rubber (Insulator)
15 Flange 15A Slit 16 Stud 20 Insulation diagnostic device 21 Outer frame (of insulation diagnostic device) 22 High frequency receiver

Claims (8)

An electrical equipment insulation diagnostic device including a metal container and a power equipment tank having an internal metal body for applying a high voltage in the metal container,
The insulation diagnosis device is configured to project one end of an insulator disposed in the power equipment tank to the outside of the power equipment tank, and above a flange provided so as to fasten the projection of the insulator. An insulation diagnostic device for electrical equipment, wherein an outer frame of the insulation diagnostic device is fitted and fixed in a slit opened in the electrical equipment.   The insulation diagnostic apparatus for an electric device according to claim 1, wherein a difference between an opening width of the slit and a width of the outer frame of the insulation diagnostic apparatus is 1 mm or less.   A plurality of ends of the insulator project from the power equipment tank, and the insulation diagnosis is performed in a slit opened upward of a flange provided so as to fasten each of the plurality of projecting portions of the insulator. The insulation diagnostic apparatus for an electric device according to claim 1, wherein an outer frame of the apparatus is fitted and fixed, and a plurality of the insulation diagnosis apparatuses are provided.   The insulation diagnostic apparatus for an electrical device according to claim 3, wherein in the plurality of insulation diagnostic apparatuses, the distance between at least two insulation diagnostic apparatuses and the corresponding projecting part of the insulating part is different from each other.   The insulation diagnostic apparatus for an electric device according to any one of claims 1 to 4, wherein a bottom surface of the slit is flattened.   The insulation diagnosis apparatus for an electrical device according to any one of claims 1 to 5, wherein rust-proof coating is performed on the slit.   The insulation diagnostic apparatus for an electrical device according to any one of claims 1 to 6, wherein the slit is subjected to conductive grease coating.   8. The electrical equipment insulation diagnostic apparatus according to claim 1, wherein a surface roughness Ra of the slit is 0.25 μm or less. 9.

Images