JP2881941B2 - Insulation monitoring antenna device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a ground fault accident in a gas insulated electric device such as a gas insulated switchgear in order to prevent a ground fault accident or the like due to insulation deterioration. The present invention relates to an insulation monitoring antenna device for detecting a partial discharge which occurs prior to the above and serves as a measure for repair. The insulation monitoring antenna device is connected to the insulation monitoring device, and when the partial discharge is detected by the insulation monitoring antenna device, the insulation monitoring device generates, for example, an alarm.

[Conventional technology]

FIG. 6 shows a schematic structure of a part for detecting a partial discharge in the gas insulated electric device. In FIG. 6, one conduit vessel 31 constituting the gas insulated electric device has an end flange 31a fastened together with an end flange 32a of another conduit vessel 32 via an insulating spacer 33 together. You. A high-voltage conductor 38 passes through the conduit vessels 31 and 32, and the high-voltage conductor 38 is supported by the insulating spacer 33 while being insulated from the conduit vessels 31 and 32. Further, the insulating spacer 33 partitions the inside of the adjacent conduit vessels 31 and 32.

In the vicinity of the flange 31a of the conduit container 31, the conduit containers 31, 32
A loop antenna 3 for detecting high-frequency electric vibration induced by a partial discharge generated between the high-voltage conductor 38 and the conduit vessels 31 and 32 therein is disposed so as to surround the conduit vessel 31. The loop antenna 34 is connected to a field strength meter 36 via a coaxial cable 35, and the field strength meter 36 is further connected to a partial discharge determination unit 37.

In the above configuration, when an insulation abnormality occurs in the conduit vessels 31 and 32 and a partial discharge occurs in the conduit vessels 31 and 32, a high-frequency electric vibration is generated along with the partial discharge. The high-voltage conductor 38 propagates in the path containers 31 and 32 in the line direction. Part of this high-frequency electric vibration is radiated as electromagnetic waves from the location of the insulating spacer 33 interposed between the conduit vessels 31 and 32 to the outside of the conduit vessels 31 and 32. The electromagnetic waves radiated outside the conduit vessels 31 and 32 are detected by the loop antenna 34 provided outside the conduit vessels 31 and 32, and the detection signal is transmitted to the electric field strength meter 36.

The electromagnetic wave pattern detected by the loop antenna 34 changes depending on whether or not a partial discharge has occurred in the conduit vessels 31 and 32.Therefore, the electric field intensity detected by the electric field strength meter 36 is smaller than that when no partial discharge occurs. Become stronger.

The partial discharge determination unit 37 detects the number of partial discharges, the intensity, and the like from the output of the electric field strength meter 36, and when the occurrence of a ground fault or the like in the conduit vessels 31, 32 is close, the detection is performed. The judgment is made and an alarm or the like is issued.

[Problems to be solved by the invention]

However, in the configuration in which the loop antenna 34 provided outside the conduit vessels 31 and 32 detects electromagnetic waves radiated with partial discharge as shown in FIG. 6, the conduit vessels 31 and 32 are made of metal. Therefore, very little electromagnetic waves leaked from the inside through the insulating spacer 33 to the outside, and the detection sensitivity of the partial discharge was low. Further, since the antenna is exposed, external noise is easily picked up, and there has been a problem of erroneous detection due to the external noise.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an insulation monitoring antenna device capable of detecting occurrence of partial discharge with high sensitivity and preventing erroneous detection of occurrence of partial discharge due to external noise.

[Means for solving the problem]

According to the insulation monitoring antenna device of the present invention, an opening is provided in a container of a gas-insulated electric device, a first conductive member having an antenna configuration slot is fitted into the opening, and the opening is formed from the outside of the container. The antenna forming slot is sealed by a second conductive member, and the antenna forming slot is formed such that the long side direction thereof is orthogonal to the longitudinal direction of the internal conductor extending substantially linearly along the inner wall of the container close to the vicinity of the opening forming portion. One conductive member is fitted.

An antenna device for monitoring insulation according to claim (2), wherein an antenna configuration slot is formed in a container of a gas-insulated electric device,
The formation portion is sealed from the outside of the container with a conductive member, and the long side direction of the antenna configuration slot extends in a substantially straight line along the inner wall of the container close to the vicinity of the formation portion of the antenna configuration slot. It is formed so as to be orthogonal to the direction.

In the antenna device for insulation monitoring according to claim (3), a first antenna configuration slot is formed in a container of a gas insulated electric device, and a second antenna configuration slot is formed in the formed portion via an insulating plate. A metal plate is overlapped with the first and second antenna configuration slots aligned with each other, and a portion where the first antenna configuration slot is formed is sealed with a conductive member from the outside of the container so as to surround the insulating plate and the metal plate. The long side direction of the antenna configuration slot is formed so as to be orthogonal to the longitudinal direction of the internal conductor that is close to the vicinity of the formation portion of the first antenna configuration slot and extends substantially linearly along the inner wall of the container. I have.

[Action]

According to the configuration described in claim (1), in the antenna configuration slot of the first conductive member fitted into the opening of the container of the gas insulated electric device, the discharge is caused by the partial discharge generated inside the gas insulated electric device. High frequency electric vibration can be detected. Moreover, since the antenna configuration slot faces the space in the container and can directly detect high-intensity high-frequency electric vibration propagating in the container, the occurrence of partial discharge can be detected with high sensitivity. Also, since the opening of the container in which the first conductive member having the antenna configuration slot is fitted is sealed from the outside of the container by the second conductive member, the state in which the insulating gas is sealed in the container is maintained. Can be
There is no decrease in insulation performance due to the provision of the antenna configuration slot, and since the second conductive member functions as an electromagnetic shielding material for the antenna configuration slot, no external noise is detected and erroneous detection due to external noise is prevented. can do.

According to the configuration described in claim (2), the high-frequency electric vibration caused by the partial discharge generated inside the gas-insulated electric device can be detected by the antenna configuration slot provided in the container of the gas-insulated electric device. . Moreover, since the antenna configuration slot faces the space in the container and can directly detect high-intensity high-frequency electric vibration propagating in the container, the occurrence of partial discharge can be detected with high sensitivity.
In addition, since the antenna forming slot forming portion of the container is sealed with a conductive member from the outside of the container, it is possible to maintain a state in which the insulating gas is sealed in the container, and the insulating performance provided by the antenna forming slot is provided. Since the conductive member functions as an electromagnetic shielding material for the antenna configuration slot, external noise is not detected, and erroneous detection due to external noise can be prevented.

According to the antenna device for monitoring insulation according to claim (3), the partial discharge generated inside the container can be detected while being electrically insulated from the container. Therefore, it is possible to protect devices for detecting partial discharge, such as the electric field strength meter and the partial discharge determination unit, against rising of the potential of the container at the time of occurrence of a ground fault, etc., and prevent their destruction. Others are the same as the insulation monitoring antenna device of claim (2).

〔Example〕

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

FIG. 1 is a sectional view of an insulation monitoring antenna device according to a first embodiment of the present invention, and FIG. 2 is a perspective view of a main part of the insulation monitoring antenna device. In FIGS. 1 and 2, a high-voltage conductor 2 passes through a conduit vessel 1 made of a metal cylinder. A substantially circular opening 3 is formed in a part of the peripheral wall of the conduit vessel 1. A peripheral portion of the opening 3 is formed so as to extend outward of the conduit vessel 1 to form a cylindrical portion (second conductive member) 4, and a flange 5 for attaching a lid is provided at a tip end of the cylindrical portion 4. A cover 10 is placed on the pipe container 1 to seal the internal space of the pipe container 1 and the cylindrical portion 4 from the outside of the pipe container 1.

On the other hand, a metal bottomed cylindrical member (first conductive member) 6
The antenna configuration slot 7 for detecting high-frequency electric vibration due to partial discharge is formed on the bottom plate, and signal extraction protrusions 8, 8 are formed in the middle of both long sides of the antenna configuration slot 7, respectively. Then, the coaxial cable 9 is passed through the circumference of the bottomed cylindrical member 6, and the distal end of the coaxial cable 9 is connected to the projections 8, 8.

The bottomed cylindrical member 6 having the above-described configuration is fitted through the cylindrical portion 4 into the opening 3 formed in the conduit vessel 1. In this case, the bottomed cylindrical member 6 has the bottom plate provided with the antenna configuration slot 7 facing the inside of the conduit vessel 1. The bottomed cylindrical member 6 is insulated from the conduit vessel 1 and the lid 10 by interposing an insulating material 11 between the conduit vessel 1 and the lid 10 or by creating a space. The conduit vessel 1 and the lid 10 are electrically connected. The bottomed cylindrical member 6 is installed such that the direction of the antenna configuration slot 7 is orthogonal to the line direction of the high-voltage conductor 2.

The coaxial cable 9 connected to the antenna configuration throttle 7 is drawn out through a coaxial sealed terminal block 12 provided on the lid 10. The conductor 13 is also connected to the bottomed cylindrical member 6, and the conductor 13 is also drawn out to the outside via the sealed terminal block 14 provided on the lid 10.

In addition, the fact that the bottomed cylindrical member 6 is insulated from the conduit vessel 1 and the lid 10 has a problem that, when it is in electrical contact, the resonance condition of the antenna changes and unnecessary contact noise is generated. However, this is to avoid the above problem. Also,
With such insulation, the voltage of the high-voltage conductor 2 can be detected by the partial pressure of the capacitor using the bottomed cylindrical member 6, and the conductor 13 is also provided as described above, and the voltage is detected by the power detector ( (Not shown).

The operation of the insulation monitoring antenna device having the above configuration will be described.

The antenna configuration slot 7 of the bottomed cylindrical member 6 has a unique resonance mode determined by the geometrical conditions of the cylindrical portion 4 and the bottomed cylindrical member 6 at the center of each long side serving as an antenna feed point. (Depending on conditions, it may be a multi-resonance mode having a plurality of resonance points). The direction of the antenna configuration slot 7 needs to be a direction that gives a potential difference between feeding points, and this direction is parallel to the magnetic field. The surge current travels through the high-voltage conductor 2 and the inner wall of the conduit vessel 1 in parallel with the traveling direction by repeatedly charging and discharging the inductance and capacitance of the distributed constant. The direction in which the side direction is orthogonal to the longitudinal direction of the high-voltage conductor 2 is best.

Then, the high-frequency electric vibration accompanying the partial discharge generated in the conduit vessel 1 is detected by the antenna configuration slot 7 and guided to the electric field strength meter (not shown) as in the conventional example, and further transmitted to the partial discharge determination unit. Can be

Note that the peripheral body of the bottomed cylindrical member 6 provided with the antenna configuration slot 7 is provided for performing capacitive coupling with the cylindrical portion 4 connected to the conduit vessel 1. Detection is possible and may be omitted.

According to the insulation monitoring antenna device of this embodiment, the conduit container 1 is inserted into the antenna configuration slot 7 of the bottomed cylindrical member 6 fitted into the opening 3 of the conduit container 1 of the gas insulated electric device.
High-frequency electric vibration caused by the partial discharge generated inside the device can be detected. In addition, since the antenna configuration slot 7 faces the space in the conduit vessel 1 and can directly detect high-frequency high-frequency electric vibration propagating in the conduit vessel 1, the occurrence of partial discharge can be detected with high sensitivity. can do. Further, since the opening 3 of the conduit vessel 1 in which the bottomed cylindrical member 6 having the antenna configuration slot 7 is fitted is sealed by the cylindrical portion 4 and the lid 10, an insulating gas is sealed in the conduit vessel 1. State can be maintained, and there is no decrease in insulation performance due to the provision of the antenna configuration slot 7.
Further, since the cylindrical portion 4 and the lid 10 function as an electromagnetic shielding material for the antenna configuration slot 7, no external noise is detected, and erroneous detection due to external noise can be prevented.

Further, since the bottomed cylindrical member 6 in which the antenna configuration slot 7 is formed is insulated from the conduit vessel 1 and the lid 10, it is possible to detect whether or not the high-voltage conductor 2 is energized by the partial pressure of the capacitor.

Further, the diameter of the cylindrical portion 4 is about 100 mm, and the partial discharge can be sufficiently detected only by providing the antenna configuration slot 7 having a length smaller than that, and surrounds the conduit vessel 1 as in the conventional example. A large antenna having a diameter of about 500 mm, such as a loop antenna, is not required, and downsizing can be achieved.

Further, it can be easily attached to an existing handhole provided in the pipeline container.

FIG. 3 is a sectional view of an insulation monitoring antenna device according to a second embodiment of the present invention, and FIG. 4 is a plan view of a main part of the insulation monitoring antenna device.

The antenna device for monitoring insulation is formed by directly forming an antenna configuration slot 21 in a direction orthogonal to the high-voltage conductor 2 on a conduit vessel 1. A signal extraction protrusion 22 at an intermediate portion between both long sides of the antenna configuration slot 21 is provided. To the coaxial cable 23.

The portion where the antenna configuration slot 21 is formed in the conduit vessel 1 is hermetically sealed by the cylindrical portion 4 and the lid 10 as in the above embodiment.

However, in this embodiment, the voltage of the high voltage
Since it is not possible to detect by dividing the voltage of the capacitor as in the embodiment, the configuration for that is omitted.

Other configurations are the same as those of the embodiment shown in FIG. 1 and FIG. 2. The antenna configuration slot 21 enables direct detection of high-frequency electric vibration accompanying partial discharge generated inside the conduit vessel 1. . The principle that partial discharge can be detected by the antenna configuration slot 21 formed directly in the conduit vessel 1 is the same as that of the first embodiment,
The following can also be considered. That is, the conduit vessel 1 and the high-voltage conductor 2 can be regarded as a distributed constant circuit (coaxial transmission line), and the high-frequency signal propagates in the conduit vessel 1 in the line direction. At this time, if there is a discontinuous portion in any of the conduit vessel 1 which is the outer conductor of the coaxial transmission line and the high voltage conductor 2 which is the inner conductor of the coaxial transmission line, impedance mismatch occurs at that portion, and A potential difference occurs in the portion. The direction in which the potential difference due to such a mismatch is generated is a direction in which the slot is orthogonal to the conductor, and
If the entire circumference of is set as a slot, the obtained potential difference also increases.

According to the insulation monitoring antenna apparatus of this embodiment, the high frequency electric vibration generated by the partial discharge generated inside the conduit vessel 1 is generated by the antenna configuration slot 21 provided in the conduit vessel 1 of the gas insulated electric equipment. Can be detected. In addition, since the antenna configuration slot 21 faces the space in the conduit vessel 1 and can directly detect high-frequency high-frequency electric vibration propagating in the conduit vessel 1, the occurrence of partial discharge can be detected with high sensitivity. can do. Further, since the portion where the antenna configuration slot 21 of the conduit vessel 1 is formed is sealed with the cylindrical portion 4 and the lid 10, the state in which the insulating gas is sealed in the conduit vessel 1 can be maintained. throttle
There is no decrease in insulation performance due to the provision of 21, and since the cylindrical portion 4 and the lid 10 function as an electromagnetic shielding material for the antenna configuration slot 21, no external noise is detected and erroneous detection due to external noise is prevented. can do.

A third embodiment of the present invention will be described with reference to FIG. In this insulation monitoring antenna device, as shown in FIG. 5, instead of directly connecting the coaxial cable 23 to the antenna configuration slot 21 provided in the conduit vessel 1, a metal plate 25 formed with the antenna configuration slot 24 is formed. An antenna configuration of the metal plate 25 is connected to a coaxial cable 23 to a signal extraction protrusion 26 at an intermediate portion of a long side of the throttle 24, and the metal plate 25 is connected to the conduit vessel 1 via an insulating plate 27. throttle
The antennas 21 and 24 are superposed in a state where they are aligned with each other, and the antenna forming slots 21 and 24 are electromagnetically coupled.

With such a configuration, high-frequency electric vibration generated in the conduit vessel 1 and caused by partial discharge is first detected in the antenna-constituting slot 21 of the conduit vessel 1, and further detected in the antenna-constituting slot 24 of the metal plate 25. It is guided, sent from the antenna configuration slot 24 of the metal plate 25 to the electric field strength meter through the coaxial cable 23, and further sent to the partial discharge determination unit.

As a result, the partial discharge generated inside the conduit vessel 1 can be detected while being electrically insulated from the conduit vessel 1. Therefore, when the ground fault accident occurs, the pipeline container 1
The electric field strength meter and the partial discharge determination unit can be protected against the floating of the electric potential, and their destruction can be prevented.

 Other effects are the same as those of the second embodiment.

In each of the above-described embodiments, only one high-voltage conductor 2 is arranged in the conduit vessel 1. However, in the case where three-phase high-voltage conductors are arranged in one conduit vessel. Naturally, the present invention can be applied to the present invention. Further, even when the conductor is surrounded by a box-shaped container, by providing an antenna configuration slot in the container in a direction perpendicular to the line direction of the conductor, it is possible to achieve the same operation and effect as the above-described embodiments. it can.

[Effects of the Invention] According to the antenna device for monitoring insulation according to claim (1), the antenna configuration slot of the first conductive member fitted into the opening of the container of the gas insulated electric device is used for the gas insulated electric device. High-frequency electric vibration caused by a partial discharge generated inside can be detected. Moreover, since the antenna configuration slot faces the space in the container and can directly detect high-frequency high-frequency electric vibrations propagating in the container,
The occurrence of partial discharge can be detected with high sensitivity. Further, since the opening of the container in which the first conductive member having the antenna configuration slot is fitted is sealed with the second conductive member from the outside of the container, the state in which the insulating gas is sealed in the container is maintained. There is no decrease in insulation performance due to the provision of the antenna configuration slot, and the second conductive member functions as an electromagnetic shielding material for the antenna configuration slot, so that external noise is not detected and error due to external noise is eliminated. Detection can also be prevented.

According to the insulation monitoring antenna device of the present invention, the high frequency electric vibration generated by the partial discharge generated inside the gas insulated electric device is detected by the antenna configuration slot provided in the container of the gas insulated electric device. can do.
Moreover, since the antenna configuration slot faces the space in the container and can directly detect high-intensity high-frequency electric vibration propagating in the container, the occurrence of partial discharge can be detected with high sensitivity. In addition, since the antenna forming slot forming portion of the container is sealed with a conductive member from the outside of the container, it is possible to maintain a state in which the insulating gas is sealed in the container, and the insulating performance provided by the antenna forming slot is provided. Since the conductive member functions as an electromagnetic shielding material for the antenna configuration slot,
Without detecting external noise, erroneous detection due to external noise can be prevented.

According to the antenna device for monitoring insulation according to claim (3), the partial discharge generated inside the container can be detected while being electrically insulated from the container. Therefore, it is possible to protect devices for detecting partial discharge, such as the electric field strength meter and the partial discharge determination unit, against rising of the potential of the container at the time of occurrence of a ground fault, etc., and prevent their destruction. Others are the same as the insulation monitoring antenna device of claim (2).

[Brief description of the drawings]

FIG. 1 is a sectional view showing the configuration of an insulation monitoring antenna device according to a first embodiment of the present invention, FIG. 2 is a perspective view of a bottomed cylindrical member having an antenna configuration slot, and FIG. FIG. 4 is a cross-sectional view showing the configuration of the insulation monitoring antenna device of the second embodiment, FIG. 4 is a plan view of a main part of the insulation monitoring antenna device of FIG. 3, and FIG. 5 is a third embodiment of the present invention. FIG. 6 is an exploded perspective view showing the configuration of the antenna device for monitoring insulation, and FIG. 6 is a schematic view showing a conventional example. 1 ... conduit vessel, 2 ... high voltage conductor, 3 ... opening, 4 ...
Tube part (second conductive member), 6: bottomed cylindrical member (first conductive member), 7: antenna configuration slot, 10: lid (second conductive member), 21: antenna configuration slot

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-2952 (JP, A) JP-A-56-159905 (JP, A) JP-A-3-56016 (JP, A) JP-A-3-56016 135311 (JP, A) JP-A-3-135312 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H02B 13/00-13/075 H02H 5/00 H01Q 1/22 G01R 31/12 G08B 7/00

Claims (3)

(57) [Claims] An opening is provided in a container of a gas-insulated electric device, a first conductive member having an antenna forming slot is fitted into the opening, and the opening is sealed with a second conductive member from the outside of the container. The first conductive member is arranged so that a long side direction of the antenna configuration slot is orthogonal to a longitudinal direction of an internal conductor which is close to the vicinity of the opening forming portion and extends substantially linearly along the inner wall of the container. An antenna device for monitoring insulation, wherein a member is fitted. 2. An antenna-forming slot is formed in a container of a gas-insulated electrical device, and the formed portion is sealed from the outside of the container with a conductive member. An antenna device for monitoring insulation, wherein the antenna device is formed so as to be orthogonal to a longitudinal direction of an internal conductor which extends in a substantially straight line along an inner wall of the container in the vicinity of a formation portion of the container. 3. A metal plate having a first antenna configuration slot formed in a container of a gas-insulated electrical device and a second antenna configuration slot formed at an area where the first antenna configuration slot is formed via an insulating plate. The antenna forming slots of the second antenna are aligned with each other, and the first antenna forming slot is sealed with a conductive member from the outside of the container so as to surround the insulating plate and the metal plate, The long side direction of the antenna configuration slot is formed so as to be orthogonal to the longitudinal direction of the internal conductor extending substantially linearly along the inner wall of the container close to the vicinity of the portion where the first antenna configuration slot is formed. Characteristic antenna device for insulation monitoring.