JPH09159719A - Apparatus for diagnosing insulation abnormality of gas insulation electric device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect a partial discharge generated inside a gas insulation electric device by providing an antenna which is constituted of a holding member of loop rings surrounding a flange part of an insulator of the electric device. SOLUTION: An antenna sensor 3 is comprised of a plurality of loop rings of different diameters and supported at an antenna-fixing stage 24 so that a ring 31 of a small diameter is set at an upper stage and a ring 32 of a large diameter is set at a lower stage. Each ring 31, 32 is connected to a coaxial cable 21 to a diagnosing device 27. At the antenna-fixing stage 24, a head of a fixing bolt is inserted in a hole of a bolt-holding metal fitting and clamped by a bait, thereby fixing the sensor 3 to an insulator-mounting part. An output of the sensor 3 is supplied to the device 27 via the cable 21. The device 27 consists of a selector, an amplifier, a CPU, etc. The CPU selects one of tank- type breakers 10 and diagnoses the presence/absence of an insulation abnormality from an electromagnetic wave detected for every breaker.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention detects the presence of an abnormality in insulation of a gas-insulated electric device by detecting a partial discharge generated inside a gas-insulated electric device such as a gas circuit breaker and a gas-insulated switchgear using an antenna. The present invention relates to a device for diagnosing the above and an antenna used for the device.

[0002]

2. Description of the Related Art When a contact portion of a conductor arranged inside a gas-insulated electric device has a contact failure, a partial discharge may occur at that portion. In addition, if metal chips, burrs, or the like are present inside the gas-insulated electric device, partial discharge may occur at the tips of these foreign substances. If such a partial discharge is left unattended, dielectric breakdown may occur, which may lead to a serious accident.

Therefore, in order to prevent serious accidents in the gas-insulated electric equipment, it is necessary to monitor the presence or absence of partial discharge inside the gas-insulated electric equipment. For this reason, a device has been proposed that monitors the presence or absence of an electromagnetic wave generated by partial discharge by an antenna and monitors the insulation abnormality.

[0004]

The gas-insulated electric equipment has a structure sealed by a metal container, and this metal container functions as a shield against electromagnetic waves. Therefore,
The electromagnetic waves generated by the partial discharge must be detected as leaks from the metal container. The insulator is considered to be the best place to place the antenna where electromagnetic waves leak.

However, the insulator part is subject to the problems of maintaining high insulation and of not disturbing the electric field. Therefore, even if the antenna, which is a conductor, is attached to the insulator portion, it is necessary to maintain high insulation and not disturb the electric field. In addition, when fixing the antenna to the insulator part, it is conceivable to fix it with the fixing bolts of the insulator flange. However, removing or loosening the fixing bolts of the insulator flange for mounting the antenna may cause gas leakage in the gas-insulated electrical equipment because the high-pressure gas is enclosed in the metal container. Furthermore, the insulator may be damaged by removing or loosening the fixing bolt. These pose the risk of impairing the reliability of gas-insulated electrical equipment.

According to the present invention, in an insulation abnormality diagnosing device for gas insulated electrical equipment, an antenna for detecting a partial discharge generated inside the gas insulated electrical equipment is arranged without adversely affecting the performance of the gas insulated electrical equipment. It is intended.

[0007]

In order to achieve the above object, the present invention provides an insulation abnormality diagnostic apparatus for detecting a partial discharge generated inside a gas-insulated electric device by using the antenna, wherein the antenna is a gas-insulated electric device. Place around the insulator mounting part of. Placing the antenna around the conductive insulator mounting part does not adversely affect the insulation of the insulator part, and
It rarely disturbs the electric field. The antenna arranged around the insulator mounting portion effectively detects the electromagnetic wave leaking from the gas-insulated electric device.

A preferred antenna used in the insulation abnormality diagnosing device of the present invention is composed of two loop-shaped rings, and a member for holding the two rings so as to surround the insulator flange portion. There is something to do.
This support member is configured such that loop-shaped rings are arranged in upper and lower stages, and the upper surface of the antenna is the same as or lower than the upper surface of the insulator flange portion and the lower surface is higher than the lower surface of the insulator flange portion.

According to this antenna structure, the insulation of the insulator is kept high and the disturbance of the electric field is minimized. Further, the supporting member may have a portion for fixing the antenna to the insulator flange by sandwiching the head of the fixing bolt of the insulator flange. When this support member is used, it is not necessary to remove or loosen the bolt for fixing the insulator flange when removing the antenna. Therefore, the gas leakage of the gas-insulated electrical equipment, the damage of the insulator, etc. will not occur.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION An example in which the present invention is applied to an insulation abnormality diagnosis of a tank type circuit breaker will be described with reference to the drawings. FIG. 1 shows the overall configuration of a tank type circuit breaker and an insulation abnormality diagnostic device. In the figure, 10 is a tank-type circuit breaker, and the tank-type circuit breaker 10 for three phases is placed on a support 26. 3 is an antenna sensor, which is a tank type circuit breaker 1
It is placed on the mounting part of the zero insulator. This antenna sensor 3
Is connected to the diagnostic device 27 by the coaxial cable 21.

FIG. 2 shows the structure of the tank type circuit breaker 10.
This will be described with reference to FIG. FIG. 2 shows a side surface of the tank-type circuit breaker 10 in a cross section, but the conductor lead-out portion on the right side of the drawing shows an outer shape, not a cross section. Metal container 12
The blocking unit 11 is housed inside. The metal container 12 contains SF
Insulating gas such as ₆ gas is enclosed. The insulator 14 is fixed to the metal container 12 by the insulator flange 28. In addition,
CT is a current transformer arranged outside the metal container 12 so as to surround the conductor, and 13 is a current transformer cover.

In the tank type circuit breaker 10 shown in FIG.
When a partial discharge 2 occurs between 1 and the metal container 12, an electromagnetic wave 1 is generated thereby. Since most of the gas-insulated electric device 10 is shielded by the metal container 12, the electromagnetic wave 1 is radiated from the mounting portion of the insulator 14 to the outside of the metal container 12. In order to detect this electromagnetic wave 1, as shown in FIG. 3, an antenna sensor 3 is arranged around an insulator flange 28 for fixing the insulator 14 to the metal container 12.

The structure of the antenna and its mounting structure will be described below. FIG. 4 shows the appearance of the antenna sensor 3. The antenna sensor 3 is composed of two loop-shaped rings having different diameters, and is supported by the antenna fixing base 24 such that the small diameter ring 31 is in the upper stage and the large diameter ring 32 is in the lower stage. The rings 31 and 32 are connected to the coaxial cable 21 and the diagnostic device 27. Also, the two rings 31, 32
Is the conductor 3 on the side opposite to the connection with the coaxial cable.
Connected by 5 to form a slot antenna. The two rings 31 and 32 may have the same diameter.

FIG. 5 shows the details of the antenna fixing base 24.
The antenna fixing base 24 includes a receiving base 23 and a bolt clamp 2
It is a combination of two. A long hole 29 is formed in the pedestal 23, and the two rings 31,
Fix 32 up and down. A hole 30 is formed in the center of the bolt sandwiching metal member 22, and a slit 33 is formed between the hole 30 and the outside of the base. Further, a tightening hole 34 is formed in a direction intersecting with the slit 33.

FIG. 5 also shows a structure for mounting the insulator 14. The insulator 14 is fixed to the metal container 12 by an insulator flange 28. At this time, the insulator flange 28 is fixed to the metal container 12 by the fixing bolt 25. The antenna fixing base 24 fixes the antenna fixing base 24 to the fixing bolts 25 by fitting the holes 30 of the bolt clamps 22 into the heads of the fixing bolts 25 and tightening the bolts through the tightening holes 34. As a result, the antenna sensor 3
Is fixed to the insulator mounting part.

FIG. 6 shows a state in which the antenna sensor 3 is attached to the insulator attachment portion. In the figure, the antenna sensor is shown in cross section. Here, the upper surface of the antenna sensor 3 is arranged below the upper surface of the insulator flange 28, and the lower surface of the antenna sensor 3 is arranged above the lower surface of the insulator flange 28. Further, the small-diameter ring 31 is arranged on the upper side and the large-diameter ring 32 is arranged on the lower side, so that the antenna sensor 3 is arranged along the outer shape of the insulator flange 28. As a result, the electric field of the insulator mounting portion is not disturbed by mounting the antenna sensor 3, and the insulation of the insulator 14 can be kept high.

The circuit configuration of the diagnostic device 27 will be described with reference to FIG. The outputs of the three antenna sensors 3 attached to different tank-type circuit breakers 10 are input to the selector 16 via the coaxial cable 21. The selector 16 selects one of the three antenna sensors 3 according to an instruction from the arithmetic processing unit 20 and connects it to the amplifier 17. The signal amplified by the amplifier 17 is input to the tuner 18. The tuner 18 is the processing unit 2
The frequency component designated by 0 is output to the A / D converter 19. The A / D converter 19 converts the analog value into a digital value and outputs it to the arithmetic processing unit 20.

The arithmetic processing unit 20 outputs an instruction for switching to the selector 16 and selects one of the tank type circuit breakers 10 to be diagnosed. Further, the tuner 19 is caused to sequentially select the frequency components peculiar to the electromagnetic waves emitted by the partial discharge. And for each tank type circuit breaker,
The presence or absence of insulation abnormality is diagnosed based on the detected electromagnetic waves. Since the diagnosis method is publicly known, the description thereof is omitted here.

[0019]

According to the present invention, in an insulation abnormality diagnosing device for gas-insulated electric equipment, an antenna for detecting a partial discharge generated inside the gas-insulated electric equipment without adversely affecting the performance of the gas-insulated electric equipment is provided. Can be placed.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of an insulation abnormality diagnosis device of the present invention.

FIG. 2 is a diagram showing a structure of a tank type circuit breaker to which the present invention is applied.

FIG. 3 is a diagram showing a structure of an insulator mounting portion of FIG.

FIG. 4 is a diagram showing a structure of an antenna sensor according to the present invention.

FIG. 5 is a diagram showing a structure of an antenna fixing base in the present invention.

FIG. 6 is a diagram showing a state in which the antenna sensor according to the present invention is arranged on an insulator mounting portion.

FIG. 7 is a block diagram showing a circuit configuration of an insulation abnormality diagnosis device according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Electromagnetic wave 2 ... Partial discharge 3 ... Antenna sensor 10 ... Tank type circuit breaker 12 ... Metal container 14 ... Insulator 16 ... Selector 17 ... Amplifier 18 ... Tuner 19 ... A / D converter 20 ... Arithmetic processing unit 21 ... Coaxial cable 22 ... Bolt clamp 23 ... Receiving stand 24 ... Antenna fixing stand 25 ... Fixing bolt 27 ... Diagnostic device 28 ... Insulator flange 29 ... Long hole 30 ... Hole 31, 32 ... Ring 33 ... Slit 34 ... Tightening hole 35 ... Conductor

Claims (4)

[Claims] 1. An insulation abnormality diagnosing device for detecting a partial discharge generated inside a gas-insulated electric device by using an antenna, wherein the antenna is arranged around an insulator mounting portion of the gas-insulated electric device. A diagnostic device for insulation abnormality of gas-insulated electrical equipment. 2. An antenna for detecting a partial discharge generated inside a gas-insulated electrical device, the antenna comprising two loop-shaped rings, the two rings being connected to the gas-insulated electrical device. And a member for holding the insulator flange portion of the device so as to surround the insulator flange portion, the support member supporting a loop ring in an upper stage and a lower stage, and whether the upper surface of the antenna is the same as the upper surface of the insulator flange portion. Alternatively, the antenna is configured such that the lower surface is arranged higher than the lower surface of the insulator flange portion. 3. The antenna according to claim 2, wherein the support member has a portion for fixing the antenna to the insulator flange by sandwiching a head of a fixing bolt of the insulator flange. 4. An insulation abnormality diagnosing device for gas insulated electrical equipment, which uses the antenna according to claim 2 or 3.