JPH044708A - Antenna device for monitoring insulation - Google Patents

Abstract

PURPOSE:To prevent the disturbance of external noise by setting a cylindrical conductive member fitted with a bottom, wherein an antenna constituting slot in the direction crossing the conductor inside a vessel at right angles, in the opening of the vessel of a gas insulation equipment. CONSTITUTION:A cylindrical conductive member 6 fitted with a bottom is set in the tubular part 4 of the opening 3 formed in the duct vessel 1 into which gas for insulation is changed. The cylindrical member 6 fitted with a bottom 6 is equipped with an antenna constituting slot 7 in the direction crossing the high voltage conductor 2 inside the duct vessel 1, and therein projections 8 and 8 are formed in the vicinity of the center on both sides of the slot 7, and the top of a coaxial cable 9 is connected as a power supply point to the antenna. The bottom of the cylindrical member 6 fitted with a bottom is covered with a cover 10 made of conductive member, and the coaxial cable 9 is led out to the outside through the coaxial sealed terminal base 12 provided in the cover 10, and the lead wire 13 connected to the cylindrical member 6 fitted with a bottom is led out to the outside through the sealed terminal base 14 of the cover 10. Hereby, electromagnetic waves generated by the corona discharge due to inferior insulation of the duct 1 can be monitored accurately without being obstructed by external noise.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention is intended to prevent ground faults from occurring due to insulation deterioration in gas-insulated electrical equipment such as gas-insulated switchgear. The present invention relates to an insulation monitoring antenna device for detecting partial discharges that occur prior to damage and serve as a guide for repair.

This insulation monitoring antenna device is connected to an insulation monitoring device, and when a partial discharge is detected by the insulation monitoring antenna device, the insulation monitoring device generates an alarm, for example.

[Traditional techniques]

FIG. 6 shows a schematic structure of a portion for detecting partial discharge in a gas-insulated electric device. In FIG. 6, one conduit container 31 constituting a gas-insulated electric device has a flange 31a at the end connected to another conduit container 3 through an insulating spacer 33.
It is fixed collinearly with the flange 32a at the end of 2.

A high-voltage conductor 38 passes through the conduit vessel 31.32, and is supported by the insulating spacer 33 while being insulated from the conduit vessel 31.32. Further, the insulating spacer 33 is connected to the adjacent conduit container 3.
1.32 It is also designed to partition the inside.

The pipe container 3 is located near the flange 31a of the pipe container 31.
A loop antenna 34 is arranged to surround the conduit vessel 31 for detecting high frequency electric vibrations induced by partial discharge generated between the high voltage conductor 38 and the conduit vessel 31.32 within the conduit vessel 31.32. ing. The loop antenna 34 is
connected to an electric field strength meter 36 via a coaxial cable 35;
A 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 container 3132 and a partial discharge occurs in the conduit container 31.32, high-frequency electric vibrations are generated, and these high-frequency electric vibrations are transmitted to the conduit. It will propagate in the direction of the line of the high-voltage conductor 38 inside the container 31,32. A part of the high-frequency electric vibration is radiated as an electromagnetic wave from the insulating spacer 330 interposed between the conduit vessels 31.32 to the outside of the conduit vessels 31.32. The electromagnetic waves radiated outside the conduit vessels 31 and 32 are detected by loop antennas 34 provided outside the conduit vessels 31 and 32, and a detection signal is transmitted to the electric field strength meter 36.

The NMI wave pattern detected by the loop antenna 34 is
It changes depending on whether or not a partial discharge occurs within the conduit vessel 31, 32, and therefore the electric field strength detected by the field strength meter 36 becomes stronger than when no partial discharge occurs.

The partial discharge determination unit 37 detects the strength of the number of partial discharges 9 from the output of the electric field strength meter 36, and detects the strength of the partial discharges 31, 32.
When a ground fault or the like is about to occur within the system, this will be determined and a warning will be issued.

[Problem to be solved by the invention]

However, in the configuration in which electromagnetic waves radiated due to partial discharge are detected by a loop antenna 34 provided outside the conduit vessel 31, 32 as shown in Fig. 6, the conduit vessel 31, 32 is made of metal. However, only a small amount of electromagnetic waves leaked from the inside through the insulating spacer 33 to the outside, and the detection sensitivity of partial discharge was low. In addition, since the antenna is exposed, it is easy to pick up external noise, causing the problem of false detection due to external noise.

Therefore, an object of the present invention is to provide an insulation monitoring antenna device that can detect the occurrence of partial discharge with high sensitivity and can also prevent false detection of partial discharge occurrence due to external noise. be.

[Means to solve the problem]

An antenna device for insulation monitoring according to claim fil provides a first conductive antenna device having an opening in a container of gas-insulated electrical equipment, and an antenna configuration slot formed in the opening in a direction perpendicular to the line direction of a conductor in the container. The opening is sealed from the outside of the container with a second conductive member.

In the insulation monitoring antenna device according to claim (2), an antenna configuration slot is formed in a container of a gas-insulated electric device in a direction perpendicular to a line direction of a conductor in the container, and the antenna configuration slot forming portion of the container is The container is sealed from the outside with a conductive member.

[For production]

According to the configuration described in claim 11, the high frequency generated by the partial discharge generated inside the gas insulated electrical equipment is generated in the antenna configuration slot of the first conductive member fitted into the opening of the container of the gas insulated electrical equipment. Electrical vibrations can be detected.Moreover, the antenna configuration slot faces the space inside the container and can directly detect the high-intensity, high-frequency electric vibrations propagating inside the container, making it possible to detect the occurrence of partial discharge with high sensitivity. In addition, the opening of the container in which the first conductive member having the antenna configuration slot is fitted is connected to the second conductive member.
Since the container is sealed from the outside with a conductive member, it is possible to maintain the state in which the insulating gas is sealed inside the container, and there is no deterioration in insulation performance due to the provision of the antenna configuration slot. Since the conductive member functions as a magnetic shield material for the antenna component slot, external noise is not detected (also, erroneous detection due to external noise can be prevented).

According to the configuration described in claim (2), it is possible to detect high-frequency electrical vibrations caused by partial discharge generated inside the gas-insulated electrical equipment using the antenna configuration slot provided in the container of the gas-insulated electrical equipment. .

Moreover, since the antenna configuration slot faces the space inside the container and can directly detect high-intensity, high-frequency electric vibrations propagating inside the container, the occurrence of partial discharge can be detected with high sensitivity. In addition, since the area where the antenna configuration slot is formed in the container is sealed with a conductive material from the outside of the container, it is possible to maintain the state in which the insulating gas is sealed inside the container, and the insulation performance achieved by providing the antenna configuration slot is Since there is no reduction in the energy consumption and the conductive member acts as an electromagnetic shielding material for the antenna configuration slot,
No external noise is detected, and erroneous detection due to external noise can be prevented.

[Actual example]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a sectional view of an insulation monitoring antenna device according to a first embodiment of the present invention, and FIG. 2 shows a perspective view of essential parts of the insulation monitoring antenna device. In Figures 1 and 2,
A high-voltage conductor 2 passes through a conduit container 1 made of a metal cylinder. A substantially circular opening 3 is provided in a part of the peripheral wall of the conduit container 1.
It is formed. The peripheral edge of the opening 30 is formed to extend outward of the conduit container 1 to form a cylindrical portion (second conductive member) 4, and the cylindrical portion 4
A flange 5 for attaching a lid is provided at the tip of the flange 5, and a lid 10 is placed on the flange 5 to seal the internal space of the conduit container 1 and the cylindrical portion 4 from the outside of the conduit container 1.

On the other hand, the metal bottomed cylindrical member (first conductive member) 6 has an antenna configuration slot 7 formed in the bottom plate for detecting high frequency electric vibration due to partial discharge, and both lengths of the antenna configuration slot 7 are formed. Protrusions 8.8 for extracting signals are formed in the middle of each side, and the coaxial cable 9 is passed through the circumference of the bottomed cylindrical member 6, and the tips of the coaxial cables 9 are connected to the protrusions 8.8, respectively. are doing.

The bottomed cylindrical member 6 configured as described above is fitted into the opening 3 formed in the conduit container 1 through the cylindrical portion 4. In this case, the bottomed cylindrical member 6 has a bottom plate provided with anti-configuration slots 7 facing the interior of the conduit vessel 1 . Moreover, this bottomed cylindrical member 6 is connected to the conduit container 1 and the lid 10 by interposing the insulating material 11 or creating a space between the conduit container 1 and the lid 10. It's on. Note that the conduit container 1 and the lid 10 are electrically connected.

Further, the bottomed cylindrical member 6 is installed so that the direction of the antenna configuration slot 7 is orthogonal to the line direction of the high voltage conductor 2.

A coaxial cable 9 connected to the antenna configuration slot 7 is led out to the outside via a coaxial sealed terminal block 12 provided on the lid 10. Further, a conductive wire 13 is also connected to the bottomed cylindrical member 6, and this conductive wire 13 is also connected to the sealed terminal block 1 provided at 110.
4 to the outside.

Note that the reason why the bottomed cylindrical member 6 is insulated from the conduit container 1 and the lid 10 is that if they come into electrical contact, the resonance conditions of the antenna will change and unnecessary contact noise will occur. However, this is to avoid the above problems. Also,
When insulated in this way, it is possible to detect the voltage of the high-voltage conductor 2 by using the bottomed cylindrical member 6 and the partial voltage of the capacitor. (not shown).

In the insulation monitoring antenna device configured as described above,
Explain the operation.

In the antenna configuration slot 7 of the bottomed cylindrical member 6, the central part of each long side acts as an antenna feeding point, and a unique resonance mode is determined by the geometrical conditions of the cylindrical part 4 and the bottomed cylindrical member 6. (Depending on the conditions, it also becomes a multi-resonance mode having multiple resonance points). The antenna configuration slot 7 must be oriented in a direction that provides a potential difference between feeding points, and this direction is parallel to the magnetic field. Since the surge current propagates through the high-voltage conductor 2 and the inner wall of the conduit vessel l in parallel to the traveling direction by repeatedly charging and discharging the distributed constant inductance and capacitance, the surge current propagates in the direction perpendicular to this current, that is, the length of the antenna configuration slot 7. The direction in which the sides are perpendicular to the longitudinal direction of the high voltage conductor 2 is best.

Then, high-frequency electric vibrations accompanying the partial discharge generated within the conduit vessel 1 are detected by the antenna configuration slot 7, and although not shown, are guided to the electric field strength needle as in the conventional example, and further sent to the partial discharge determination unit. It will be done.

Note that the circumferential body of the bottomed cylindrical member 6 provided with the antenna configuration slot 7 is provided to perform capacitive coupling with the cylindrical portion 4 connected to the conduit container 1, but even without this, partial discharge can still occur. Detection is possible and may be omitted.

According to the insulation monitoring antenna device of this embodiment, the inside of the conduit container 1 is inserted into the antenna structure slot 7 of the bottomed cylindrical member 6 fitted into the opening 3 of the conduit container 1 of gas-insulated electrical equipment. High-frequency electrical vibrations caused by the generated partial discharge can be detected.

Moreover, since the antenna configuration slot 7 faces the space inside the conduit vessel 1 and can directly detect high-intensity, high-frequency electric vibrations propagating inside the conduit vessel 1, the occurrence of partial discharge can be detected with high sensitivity. can do. Furthermore, since the opening 3 of the conduit container 1 into which the bottomed cylindrical member 6 having the antenna configuration slot 7 is fitted is sealed with the cylindrical portion 4 and the lid 10, an insulating gas is sealed in the conduit container 1. The insulation performance is not deteriorated due to the provision of the antenna configuration slot 7, and the cylindrical portion 4 and the lid 10 are
Since it functions as an electromagnetic shielding material for the antenna configuration slot 7, external noise is not detected and erroneous detection due to external noise can be prevented.

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

In addition, the diameter of the cylindrical portion 4 is approximately 100 fi, and it is possible to sufficiently detect partial discharge by providing the antenna component slot 7 having a length smaller than this. Diameter 500 like a loop antenna
A device as large as 1.0 m is not necessary, and miniaturization can be achieved.

Furthermore, it can be easily attached to an existing hand hole provided in the conduit container.

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

This insulation monitoring antenna device has an antenna configuration slot 21 directly formed in a conduit container 1 in a direction perpendicular to the high voltage conductor 2, and a protrusion 22 for signal extraction in the middle of both long sides of the antenna configuration slot 21. A coaxial cable 23 is connected to.

The area where the antenna configuration slot 21 is formed in the conduit container 1 is sealed by the cylindrical portion 4 and Mlo as in the previous embodiment.

However, in this embodiment, since the voltage of the high voltage conductor 2 cannot be detected by dividing the voltage of the capacitor as in the first embodiment, the configuration for this purpose is omitted.

The rest of the configuration is similar to the embodiment shown in FIGS. 1 and 2, and the antenna configuration slot 21 allows direct detection of high-frequency electric vibrations associated with partial discharge generated inside the conduit vessel 1. .

Antenna configuration slot 2 formed directly in this conduit container 1
The principle by which partial discharge can be detected using 1 is the same as that of the first embodiment, but it can also be considered as follows. 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 inside the conduit vessel 1 in the line direction. At this time, if there is a discontinuity in either the conduit container 1, which is the outer conductor of the coaxial transmission line, or the high voltage conductor 2, which is the inner conductor of the coaxial transmission line, impedance mismatch will occur at that part. A potential difference occurs in this part.

The direction in which a potential difference is created due to such mismatch is the direction in which the slots are perpendicular to the conductor, and if the entire circumference of the conduit container 1 is made into slots, the potential difference obtained will also become larger.

According to the insulation monitoring antenna device of this embodiment, high-frequency electrical vibrations generated by partial discharge generated inside the conduit vessel 1 are transmitted through the antenna configuration slot 21 provided in the conduit vessel 1 of gas-insulated electrical equipment. can be detected. Moreover, since the antenna configuration slot 21 faces the space inside the conduit vessel 1 and can directly detect high-intensity, high-frequency electric vibrations propagating inside the conduit vessel 1, the occurrence of partial discharge can be detected with high sensitivity. can do. In addition, the forming portion of the antenna configuration slot 21 of the conduit container 1 is set to the cylindrical portion 4 and
10, it is possible to maintain the state in which the insulating gas is sealed in the conduit container 1, and there is no deterioration in insulation performance due to the provision of the antenna configuration slot 21. 10 functions as an electromagnetic shielding material for the antenna configuration slot 21, external noise is not detected and erroneous detection due to external noise can be prevented.

A third embodiment of the invention will be described based on FIG.

This insulation monitoring antenna device, as shown in Fig. 5,
Rather than directly connecting the coaxial cable 23 to the antenna configuration slot 21 provided in the conduit container 1, a metal plate 25 in which an antenna configuration slot 24 is formed is provided, and this metal plate 2
The coaxial cable 23 is connected to the signal extraction protrusion 26 in the middle of the long side of the antenna configuration slot 24 of No. are superimposed in a matched state, and both antenna component slots 2124 are electromagnetically coupled.

With this configuration, high-frequency electric vibrations accompanying partial discharge generated within the conduit vessel 1 are first detected by the antenna configuration slot 21 of the conduit vessel 1, and are further detected by the metal plate 25.
from the antenna configuration slot 24 of the metal plate 25 through the coaxial cable 23 to the electric field strength meter, and further to the partial discharge determination unit.

As a result, partial discharge generated inside the conduit vessel 1 can be detected while being electrically insulated from the conduit vessel 1. Therefore, it is possible to protect the field strength meter and the partial discharge determination unit from rising potential of the conduit container 1 when a ground fault occurs, etc., and to prevent their destruction.

Other effects are similar to those of the second embodiment.

In addition, in each of the above embodiments, one high voltage conductor 2 is placed in the conduit container 1.
Although the case where only books are arranged has been described, it is natural that the present invention can be applied to a case where high voltage conductors for three phases are arranged in one conduit container. Furthermore, even when the conductor is surrounded by a box-shaped container, the same effects as in each of the above embodiments can be achieved by providing the antenna configuration slot in the container in a direction perpendicular to the line direction of the conductor. can.

〔Effect of the invention〕

According to the insulation monitoring antenna device according to claim 11, the antenna configuration slot 7 of the first conductive member fitted into the opening of the container of the gas insulated electrical equipment generates the noise inside the gas insulated electrical equipment. It is possible to detect high-frequency electrical vibrations generated by partial discharge.

Moreover, since the antenna configuration slot faces the space inside the container and can directly detect high-intensity, high-frequency electric vibrations propagating inside the container, the occurrence of partial discharge can be detected with high sensitivity. Furthermore, since the opening of the container into which the first conductive member having the antenna configuration slot is fitted is sealed from the outside of the container with the second conductive member, the state in which the insulating gas is sealed inside the container can be maintained. The insulation performance does not deteriorate 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, external noise is not detected and errors caused by external noise are prevented. Detection can also be prevented.

According to the insulation monitoring antenna device according to claim (2),
High-frequency electrical vibrations caused by partial discharge generated inside the gas-insulated electrical equipment can be detected by an antenna configuration slot provided in the container of the gas-insulated electrical equipment. Moreover, since the antenna configuration slot faces the space inside the container and can directly detect high-intensity, high-frequency electric vibrations propagating inside the container, the occurrence of partial discharge can be detected with high sensitivity. In addition, since the area where the antenna configuration slot is formed in the container is sealed with a conductive material from the outside of the container, it is possible to maintain the state in which the insulating gas is sealed inside the container, and the insulation performance achieved by providing the antenna configuration slot is Since the conductive member functions as a 1i magnetic shield material for the antenna component slot, external noise is not detected, and erroneous detection due to external noise can be prevented.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the structure 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 in which an antenna configuration slot is formed, and FIG. A cross-sectional view showing the configuration of the insulation monitoring antenna device of the second embodiment, FIG. 4 is a plan view of the 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 structure of an insulation monitoring antenna device, and FIG. 6 is a schematic diagram showing a conventional example. l...Pipeline container, 2...High pressure conductor, 3...Opening,
4... Cylindrical part (second conductive member), 6... Bottomed cylindrical member (first conductive member), 7... Antenna configuration slot, 10... Lid (second conductive member) , 21...Antenna configuration slot

Claims (2)

[Claims] (1) An opening is provided in the container of the gas-insulated electrical equipment, and a first conductive member having an antenna configuration slot formed in a direction perpendicular to the line direction of the conductor in the container is fitted into the opening;
An antenna device for monitoring insulation, characterized in that the opening is sealed from the outside of the container with a second conductive member. (2) An antenna configuration slot is formed in the container of the gas-insulated electrical equipment in a direction perpendicular to the line direction of the conductor in the container, and the antenna configuration slot forming part of the container is sealed with a conductive member from the outside of the container. An antenna device for insulation monitoring characterized by: