JP2002340969A - Partial discharge diagnostic sensor for gas insulated switch gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently detect an electromagnetic wave accompanying partial discharge generated in a high voltage vessel in a flexible structure form the surface of an insulation spacer and to easily realize shielding of outside noise. SOLUTION: A highly flexible external sensor for detecting that the high frequency electromagnetic wave generated by accompaniment of the partial discharge leaks from a spacer is provided, has stable detection sensitivity by combining a cushion body and a shield belt therewith as shown in figure 2, and the influence of the outside noise is suppressed. Furthermore, it can cope with always attaching specifications by combining a flexible metal cover. It can be stably attached to the surface of an arbitrary sized spacer, and the influence of the outside noise can be suppressed. Kinds of combined parts are not enough, and the economical external sensor can be provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a detection unit (sensor) of a device for diagnosing the presence or absence of an abnormality in insulation characteristics of a high-voltage electrical equipment using a gas having excellent insulation characteristics such as SF6 gas as an insulation medium.
About.

[0002]

2. Description of the Related Art In a high-voltage device used in a substation or the like, a high-voltage conductor portion is mechanically supported by an insulator, and the insulation is maintained.

[0003] In order to confirm the reliability of the insulation performance of these devices, it is extremely important to check for the occurrence of partial discharge from insulators, metal conductors and the like inside the devices. Therefore, various methods for performing insulation diagnosis of equipment through measurement of partial discharge have been proposed and put into practical use.

[0004] Sensors for measuring partial discharge mainly include those that capture mechanical signals (sounds, vibrations, etc.) associated with partial discharges and those that capture electrical signals (high-frequency currents, electromagnetic waves, etc.). As an example of the latter, as described in JP-A-3-15771, a sensor (electromagnetic wave detection antenna) is mounted on the wall of a container of a high-voltage device, and the signal of the sensor is used to perform internal insulation diagnosis and localization of a generated part. How to do
It is used as a method that can detect abnormalities inside equipment with high sensitivity with little influence of external noise.

[0005] The mainstream of high voltage equipment is a gas insulated switchgear in which SF6 gas having excellent insulation properties is sealed in a sealed container and a circuit breaker or disconnector for opening and closing an electric circuit is incorporated therein. I have. In this case, it is known that a partial discharge generated inside becomes a pulse steeper than an air corona generated outside and generates an electromagnetic wave having more high frequency components. For this reason, it has been confirmed that a method of diagnosing the presence or absence of an abnormality without being affected by external noise by analyzing the frequency component of the partial discharge signal is effective.

[0006]

In the above-mentioned prior art, it is necessary to provide electrodes in advance on the inner wall of the container as a sensor, and it is easy to cope with a newly manufactured high-voltage device, but the amount is enormous. Aged equipment has the disadvantage that it is necessary to stop the operation and install a sensor due to equipment modification, the cost for equipment modification increases, and the application of diagnostic technology is restricted.

[0007] In particular, the risk of new contaminants caused by stopping and repairing the equipment and the effect on the environment due to the release of SF6 gas to the atmosphere are assumed. It has become.

As a solution to this problem, a method has been applied in which an antenna is attached to the surface of an insulating spacer provided at various places in a high-voltage device and diagnosis is performed using electromagnetic waves detected by the antenna. Is more susceptible to external noise, which hinders highly sensitive diagnosis.

An object of the present invention is to provide a structure which can suppress the influence of external noise by using an antenna attached to the surface of a spacer and can be easily attached to a high-voltage device every time measurement is performed.

Another object of the present invention is to provide a mounting structure which can easily be adapted to the sizes of spacers having various kinds of curvatures according to the rating of the GIS. Furthermore,
An object of the present invention is to provide an external sensor that can be applied as a constantly mounted type.

[0011]

According to the first and second aspects of the present invention,
It consists of an antenna element that detects electromagnetic waves, a cushioning body and a shielding belt that are insulating insulators for uniformly applying the antenna element to the spacer surface, and fixes the antenna element to the spacer surface and into the container from the spacer surface. Prevents external noise from entering.

According to a third aspect of the present invention, a spacer is provided with a slit so that the spacer can be adapted to an arbitrary curvature of the spacer.

A fourth aspect of the present invention is to provide a stable mounting structure and enhance the shielding function against external noise when the external sensor is always mounted.

[0014]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
Explanation will be made based on 7.

An embodiment of the present invention will be described by taking a general gas-insulated switchgear as an example of high-voltage equipment.

In FIG. 1, a metal container 1 includes an insulating spacer 4
, And are connected by flanges 2 at the ends of the containers. Inside the container is SF6 with excellent insulation properties
A gas is filled at a predetermined pressure, and a center conductor 3 electrically connected to a transmission line not shown in detail is arranged,
It is supported while maintaining electrical insulation by the insulating spacer 4 and the like.

In this structure, since the metal container 1 is grounded by the grounding wire 5, it has a shielding effect against external noise, but the insulating spacer 4 has no shielding effect. Electromagnetic waves existing outside enter the metal container 1. Conversely, the electromagnetic waves associated with the partial discharge generated inside the metal container 1 leak out from the insulating spacer 4 to the outside.

When performing insulation diagnosis from outside the container, an external sensor 7 for detecting the leaking electromagnetic wave is attached to the surface of the insulating spacer 4 and the signal cable 8 is connected to a signal processing unit 21 (not shown in detail). Do. When the built-in sensor 6 is mounted in the container 1 in advance, a more sensitive internal diagnosis is possible by directly taking in the signal of this sensor.

FIG. 2 shows how the external sensor 7 is attached.

First, a flexible external sensor 7 composed of an antenna element 9, an insulating sheath 10 for protecting the element, and a terminal 11 for extracting a signal detected by the element is applied to the surface of the insulating spacer 4 as shown in FIGS. .

Next, a cushion body 12 having the shape shown in FIG. 3 is applied from above, and a shielding belt 13 is further covered from above. The shielding belt 13 surrounds the entire circumference of the spacer, and an external sensor
The cushion body 12 is compressed by a predetermined amount by a fastener (not shown in detail) on the side opposite to 7 or the like. Due to the compression reaction force of the cushion body 12, the antenna element 9
Is pressed against the surface of the insulating spacer 4, and a stable signal output can be taken out from the terminal 11.

The shielding belt 13 is brought into a ground potential by electrically contacting the flanges 2 at both ends of the insulating spacer 4 in a mounted state, thereby preventing external noise from entering the container. With this combination, it is possible to cover the entire circumference of the surface of the insulating spacer 4 of the high-voltage device having various sizes (diameters).

Further, by winding only the same type of shielding belt 13 around the adjacent insulating spacer 4, it is possible to prevent external noise from entering from the spacer where no sensor is attached.

The cushion body 12 is made of a compressible insulating material such as a foamed rubber material and has a shape as shown in FIG.
Ideally, the thickness dimension is the wavelength (λ) of the signal frequency to be detected
Is preferably about λ / 4. Also, conductive film 1 on the side
By applying 4 and making this film the same potential as the shielding belt 13, the effect of shielding external noise can be improved.
It is preferable that the slits 15 are provided on the cushion body 12 and the tapered portions 16 are formed on both sides to smoothly wind the shielding belt 13.

According to the present embodiment, the size of the sensor for insulation diagnosis and the size of the cushion body can be unified into one type, and various sizes can be obtained by adjusting the length of the shielding belt 13 for shielding and fixing the sensor. It becomes possible to apply an external sensor to a high voltage device.

Furthermore, when the external sensor of the present invention is applied for constant monitoring, the size of the spacer at the site where the sensor is to be mounted is predetermined, so that the metal cover 18 is formed on the shielding belt 13 in the form shown in FIGS. In addition, it is possible to enhance the environmental resistance of the external sensor 7 and improve the effect of shielding external noise. The metal cover 18 is preferably made of a copper plate having flexibility and a high shielding effect in order to improve the handleability.
In addition, a metal cover slit 22 is provided on the side surface, and flanges 2 are provided from both sides through an embedding fitting 20 in the spacer 4.
By using the heads of the bolts 17 that fix the heads to make them detachable, the mountability is improved. In this case, in order to prevent a sheath current flowing on the surface of the metal container 1 from flowing through the metal cover 18, it is preferable to attach an insulating plate 19 to the inner surface on one side of the metal cover 18. If the same combination of the metal covers 18 is used to cover the entire circumference of the spacer as shown in FIG. 7, the number of types of components can be reduced and the economy can be improved.

Even when the same metal cover 18 cannot be applied due to the configuration of the GIS, it is possible to reduce the number of types by examining the structure in advance.

[0028]

According to the external sensor mounting method of the present invention, for example, when diagnosing a switchgear in combination with a portable diagnostic device, equipment of various sizes can be easily provided without bringing many types of sensors. There is an effect that the partial discharge diagnosis can be performed. In addition, since each component can be standardized, the production cost due to mass production is reduced, and a system with good cost performance can be provided.

Further, it is possible to use a combination of a metal cover and a sensor which is always mounted, and is useful as a retrofit sensor for realizing high-sensitivity online diagnosis for existing equipment.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an example of attaching an external sensor according to the present invention.

FIG. 2 is a detailed view of attachment of an external sensor.

FIG. 3 is a diagram showing a shape of a cushion body.

FIG. 4 is a structural view of an external sensor.

FIG. 5 is a side view of an external sensor.

FIG. 6 is a diagram in which a metal cover is combined with an external sensor.

FIG. 7 is a side view in which a metal cover is combined.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Metal container, 2 ... Flange, 3 ... Center conductor, 4 ... Insulating spacer center conductor, 5 ... Grounding wire, 6 ... Built-in sensor, 7 ...
External sensor, 8 ... signal cable, 9 ... antenna element, 1
0: insulation sheath, 11: terminal, 12: cushion body, 1
3: shielding belt, 14: conductive film, 15: slit, 16
... taper, 17 ... bolt, 18 ... metal cover, 19 ...
Insulation plate, 20: mounting bracket, 21: signal processing unit, 2
2: Metal cover slit.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2G015 AA10 BA02 CA01 5G017 EE02 EE07 5G028 GG16 GG21 GG24 5G365 DN04

Claims (4)

[Claims] 1. An electromagnetic wave detecting antenna element is applied to the surface of an insulating spacer constituting a gas insulated switchgear (GIS), and a cushion body that also serves as an electromagnetic wave shield is combined thereon to perform rear shielding, and an external sensor is provided. A partial discharge diagnostic sensor comprising: 2. An external sensor for diagnosing partial discharge, wherein a cushion body is attached by being compressed by a predetermined amount with a shielding belt. 3. A plurality of slits are provided in the cushion body,
An external sensor for partial discharge diagnosis, which is adapted to an arbitrary curvature of a spacer. 4. A press fitting is further applied in a combined state of the antenna element, the cushion body and the shielding belt, one side of the press fitting is insulated, and the other side is grounded to prevent a sheath current to the fitting. Features an external sensor that can always be mounted.