JP4456975B2 - Accident detection device for gas insulated switchgear - Google Patents

Description

  The present invention relates to an accident detection device for a gas-insulated switchgear that detects an internal fault of a gas-insulated switchgear (GIS) based on an energized current.

  When an accident occurs in a circuit including the GIS, it is necessary to determine whether or not an accident has occurred in the GIS in order to identify the cause (accident section or accident occurrence location). In other words, it is necessary to detect whether the accident location is inside or outside the GIS.

  Accident discrimination in GIS can be performed by monitoring an energized current detected by a current sensor such as a CT (current transformer). In order to determine whether the accident location is inside or outside the GIS, the energization current is detected inside the GIS, and the accident is determined based on this detection. For this purpose, a current sensor such as CT may be installed in the GIS in advance to detect the energization current. By monitoring the presence / absence of an energization current detected in the GIS from the outside (for example, the presence / absence of leakage current or surge current), it is possible to determine whether or not there is an accident location in the GIS.

  There are a wide variety of switchgears used in the power system, including new and old, and there are many GISs that do not have a current sensor for determining internal accidents. However, in order to identify the cause of an accident when it occurs, it is necessary to determine the presence or absence of an internal accident even for a GIS in which the sensor is not installed. For this purpose, it is necessary to newly install the current sensor inside the GIS.

  However, sulfur hexafluoride (SF6) or the like is enclosed as an insulating gas inside the GIS. Therefore, when trying to install the current sensor in the interior, the insulating gas is removed and then the inside is disassembled, and the current sensor is installed and then the insulation gas is sealed again. Will occur. SF6, which is frequently used as an insulating gas, is excellent in suitability as an insulating gas, but it is pointed out that it may be a powerful greenhouse gas, and it is difficult to handle and treat it.

  The present invention has been made in view of the problems as described above, and its purpose is to easily detect an energization current for determining an internal accident of a GIS without touching the inside of the GIS. (Attachment) An object of the present invention is to provide a GIS accident detection apparatus which can be accurately performed only by a configuration.

The means of the present invention is characterized by the following configuration (1).
(1) In the GIS accident detection device for detecting an internal accident of the GIS based on the energization current, a Rogowski coil is used for the energization current sensor unit, and the Rogowski coil is connected to the conductor drawing portion of the switchgear. A GIS accident detection device installed at a position surrounding a protruding insulating bushing provided in
A shield ring is installed at a position surrounding the insulating bushing by a fixture, and the Rogowski coil is held by an annular holder concentrically with the shield ring, and the annular holder is used as a fixture of the shield ring. A GIS accident detection device characterized by being attached and fixed .

( 2 ) The GIS accident detection device according to ( 1 ), wherein the Rogowski coil is installed between the shield ring and the casing of the GIS.

( 3 ) In (1) or (2) , the Rogowski coil is formed by winding a coil around a bobbin that is annularly closed by connecting both ends of the joint to each other. An accident detection device of GIS, wherein one end of a bobbin is formed by screw connection into which the other end is screwed.

  It is possible to accurately detect the energization current for determining an internal accident of the GIS, without touching the inside of the GIS, with only a simple addition (attachment) configuration to the outside. As a result, even in a circuit including a GIS that does not have a current sensor for determining an accident inside, it is possible to accurately detect an accident section without causing a large-scale and troublesome work and construction. Become.

  FIG. 1 shows an embodiment of an accident detection apparatus according to the present invention. The apparatus shown in the figure uses a Rogowski coil 21 as a current sensor that forms the main part. The Rogowski coil 21 is installed and used outside the GIS (Gas Insulated Switchgear) 10 and detects an energization current of the GIS 10. This detection output (detection information) is transmitted to the digital processing system 40 via the analog pre-circuit 30.

  An insulating bushing 12 is provided in the conductor lead-out portion of the GIS 10. The bushing 12 has a protruding shape that protrudes outside the casing of the GIS 10. The lead-in conductor (distribution line) 11 that penetrates the casing of the GIS 10 is insulated by passing through the bushing 12.

  A shield ring 13 is installed on the outer periphery of the bushing 12. The shield ring 13 is for preventing the concentration of the electric field, and is attached so as to surround the bushing 12 so as to form a large circle centered on the bushing 12.

  The Rogowski coil 21 is installed at a position surrounding the protruding insulating bushing 12 provided in the conductor lead-out portion of the GIS 10. And like the said shield ring 13, it attaches so that the big circle centering on the bushing 12 may be formed. The Rogowski coil 21 installed in this way detects the energizing current flowing through the lead-in conductor 11 by surrounding the lead-in conductor 11 of the GIS 10 in an annular shape.

  The detection output of the Rogowski coil 21 is input to the pre-circuit 30 via a signal line such as a coaxial cable, where it is subjected to analog processing such as integration, filtering, impedance conversion, and the like, and then digitally converted to the digital processing system 40. Entered. The digital processing system 40 is configured using a microcontroller, and executes functions such as a current monitor 41, a frequency discrimination filter 42, a signal analysis 43, and an accident determination 44 by digital processing.

  With the configuration as described above, the energization current of the GIS 10 can be detected. It should be noted here that the Rogowski coil 21 is installed at a position surrounding the projecting insulating bushing 12 provided in the conductor lead-out portion of the GIS 10, and the energization current is detected at this installation location. It is that. In this installation location, the current flowing in the conductor portion in the bushing 12, the so-called soot-pipe inner conductor 111, is detected. By installing the ski coil 21, it has been revealed by the present inventors that an internal accident can be determined by detecting an energized current under almost the same conditions as when a current sensor such as a CT is installed inside the GIS 10. .

  Further, it should be noted that the conductor 111 of the measurement location surrounded by the Rogowski coil 21 is also a location where high voltage insulation is provided by the bushing 12. As a result, it is possible to accurately detect the energization current inside the GIS 10 with only a simple addition (attachment) configuration outside the GIS 10 without adding new insulation equipment.

  As described above, energization current detection for determining an internal accident of the GIS 10 can be accurately performed with only a simple addition (attachment) configuration without touching the inside of the GIS 10. As a result, even in a circuit including a GIS that does not have a current sensor for determining an accident inside, it is possible to accurately detect an accident section without causing a large-scale and troublesome work and construction. Become.

  FIG. 2 shows a specific embodiment relating to the installation of the Rogowski coil 21. As shown in the figure, the Rogowski coil 21 is installed by using a fixing tool 16 of a shield ring 13 installed around the insulating bushing 12. The shield ring 13 is attached and held and fixed to an annular fixture 16. The fixture 16 is attached to the outside of the bushing 12 by a bracket 15.

  The Rogowski coil 21 is held by an annular holder 161 concentric with the shield ring 13. The holder 161 is attached and fixed concentrically to the fixture 16 of the shield ring 13.

  In the illustrated form, the Rogowski coil 21 is installed between the shield ring 13 and the casing of the GIS 10, but this position is not easily affected by surges such as lightning due to the electric field shielding effect of the shield ring 13. There is also. Therefore, placing the Rogowski coil 21 there is effective in preventing surge destruction of the circuit 30 and the system 40 connected to the Rogowski coil 21 in addition to preventing destruction of the Rogowski coil 21 itself.

  FIG. 3 shows an embodiment of a circuit portion for processing the detection output of the Rogowski coil 21. The Rogowski coil 21 outputs an analog detection current. This analog output is input to the pre-circuit 30 for analog processing.

  The pre-circuit 30 includes an integrator 31, an LPF (low pass filter) 32, an A / D converter 33, and the like, and preprocesses the detection current. This processing output is digitally converted by the A / D converter 33 and delivered to the digital processing system 40 described above.

  Note that the processing functions of the pre-circuit 30 and the digital processing system 40 use, for example, an optical fiber as a main part excluding a circuit that is desirably placed close to the Rogowski coil 21, such as a front-end amplifier. It may be remotely installed via a communication line.

  FIG. 4 shows a schematic configuration of the Rogowski coil 21 used in the present invention. As shown in the figure, the Rogowski coil 21 is formed by a winding 22 wound along an annular bobbin 25 and a return winding 23 for preventing the winding 22 from forming a one turn. The The bobbin 25 is configured using a flexible insulating tube made of resin or the like, bent in an annular shape, and both ends thereof are connected to each other by joint portions 26.

  The Rogowski coil 21 is an air-core coil, and is installed so that the conductor 111 passes through substantially the center of the ring, thereby detecting a change in magnetic flux due to a current flowing through the conductor 111. The detected output appears at both ends of the windings 22 and 23 as the induced electromotive force Er.

  Since the Rogowski coil 21 can have a large ring inner diameter as one of its features, it is suitable for current measurement in a high voltage portion. Installation to the existing GIS can be easily performed in the form of an attachment by attaching and detaching the joint part 26.

  FIG. 5 shows an embodiment of the Jonito part 26. The joint portion 26 shown in the drawing is provided with a fitting convex portion 271 and a fitting concave portion 272 which are separately provided at one end and the other end of the bobbin 25, and both the 271 and 272 are fitted and connected, and the connected state is removed by a set screw 273. It is configured to stop and fix. This joint structure has a simple structure and is easy to attach and detach, but the length (d) of the joint portion 26 that is a non-winding portion needs to be secured to some extent due to the presence of the set screw 272.

  FIG. 6 shows another embodiment of the Jonito part 26. In the joint portion 26 shown in the figure, a male screw portion 281 and a female screw portion 272 are provided separately at one end and the other end of the bobbin 25, and both the members 281 and 282 are screwed together. The male screw portion 281 is pivotally coupled to one end of the bobbin 25 together with a screw head (flange portion) 281a integrated therewith.

  This joint structure is simple in structure and easy to attach and detach as shown in FIG. 5, but further, the length (d) of the joint portion 26 is reduced by eliminating the need to prevent the setscrew 272 from coming off. It has the feature that it can be greatly reduced. The joint portion 26 is a non-winding portion, and the width (d) of the non-winding portion can be reduced.

  Thus, for example, it has been found that even if the position of the conductor passing through the Rogowski coil 21 is slightly decentered, the measurement error due to the decentering can be greatly reduced. The Rogowski coil 21 having such a joint structure is particularly suitable for the application of the present invention.

  As described above, the present invention has been described based on the representative embodiments. However, the present invention can have various forms other than those described above. In addition, the above-described embodiment is premised on the use of detecting the GIS energizing current and specifying the accident section when an accident occurs. However, for example, a use of detecting a partial discharge before an accident is possible.

  It is possible to accurately detect the energization current for determining an internal accident of the GIS, without touching the inside of the GIS, with only a simple addition (attachment) configuration to the outside. As a result, even in a circuit including a GIS that does not have a current sensor for determining an accident inside, it is possible to accurately detect an accident section without causing a large-scale and troublesome work and construction. Become.

It is the schematic which shows one Embodiment of the accident detection apparatus of the gas insulated switchgear by this invention. It is the top view and sectional side view which show the principal part of embodiment regarding installation of the Rogowski coil in this invention. It is a block diagram which shows the example of schematic structure of the pre-circuit which processes the detection output of a Rogowski coil analog. It is a conceptual diagram which shows schematic structure of a Rogowski coil. It is a side view which shows embodiment regarding the joint part of a Rogowski coil. It is a side view which shows more preferable embodiment regarding the joint part of the Rogowski coil.

Explanation of symbols

10 GIS with gas-sealed structure 11 Lead-in conductor (distribution line)
111 Bushing inner conductor (conductor inside pipe)
DESCRIPTION OF SYMBOLS 12 Insulation bushing 13 Shield ring 15 Bracket 16 Fixing device of shield ring 13 161 Holder of Rogowski coil 21 21 Rogowski coil 22 Winding 23 Return winding 25 Annular bobbin 26 Joint part 271 Insertion convex part 272 Insertion concave part 273 Set screw 281 Male thread part 281a Screw head (flange part) 282 Female thread part 30 Pre-circuit 31 Integrator 32 LPF (low pass filter) 33 A / D converter 40 Digital processing system 41 Current monitor part 42 Frequency discrimination filter 43 Signal Analysis Unit 44 Accident Judgment Unit

Claims (3)

In an accident detection device for a gas-insulated switchgear that detects an internal fault of a gas-insulated switchgear based on an energization current, a Rogowski coil is used for the energization current sensor, and the Rogowski coil is connected to the switchgear of the switchgear An accident detection device for a gas insulated switchgear installed at a position surrounding a protruding insulating bushing provided in a conductor lead-out part ,
A shield ring is installed at a position surrounding the insulating bushing by a fixture, and the Rogowski coil is held by an annular holder concentrically with the shield ring, and the annular holder is used as a fixture of the shield ring. An accident detection device for a gas insulated switchgear characterized by being mounted and fixed . Oite to claim 1, said Rogowski coil is fault detection device for a gas insulated switchgear, characterized in that is provided between the housing of the shield ring and the GIS. 3. The Rogowski coil according to claim 1 or 2, wherein the Rogowski coil is formed by winding a coil around a bobbin that is annularly closed by connecting both ends at a joint part. An accident detection device for a gas insulated switchgear characterized by being formed by a screw connection screwed into an end.

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