JPH0287914A - Abnormal detector of gas insulating switchgear - Google Patents

Abstract

PURPOSE:To make it possible to detect plural kinds of abnormalities by providing an easily exchangeable band-pass filter permeable only to a signal of the oscillation in a specific frequency band. CONSTITUTION:Partial discharge generating from an insulator of a spacer and the like holding a high voltage conductor 2, etc., and the mixture of a metallic foreign matter are, for example, regarded as abnormalities in a metal container 1, and in any case, this is transmitted to the wall of the container 1 as oscillations or sound waves. The oscillations are detected by an oscillation detector 4 to be transmitted to a receiver 6 through a cable 5 as an electric signal. It is transmitted to an easily exchangeable band-pass filter 9 in the receiver 6, and a signal only in a specific frequency band is detected. According to the constitution, plural kinds of internal abnormalities with different generation frequency can be detected by one abnormality detector.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a device for detecting an abnormality occurring in a closed gas insulated switchgear.

(Conventional technology) In recent years, due to the need to strengthen substation equipment due to the soaring cost of land and the increase in power supply in urban areas, disconnectors and circuit breakers have been developed using SF6 gas, which has excellent insulation and arc-extinguishing properties. The so-called gas insulated switchgear (hereinafter referred to as GIS), which houses and arranges substation equipment such as in a sealed container, is environmentally resistant and has a compact installation volume per KV/A, is now in widespread use.

Although the above-mentioned GIS has various advantages such as being more compact and reducing the number of exposed live parts in the grounded tank, it is difficult to perform maintenance diagnosis due to higher performance, increases the time required for maintenance and repair work, and is prone to abnormalities inside the container. If this occurs, there is a drawback that its reliability is significantly reduced.

Therefore, in order to improve the reliability of GIS, we have been working on the appropriate design and manufacturing of equipment, but as part of improving the quality of power supply capacity, we have also been making efforts to confirm the reliability of the entire equipment and Monitoring has become necessary, and various effective means have been studied.

One method for this purpose is to detect partial discharges and metal foreign objects occurring inside the GIS.

FIG. 3 shows a specific system for detecting internal abnormalities. A high voltage conductor 2 is disposed inside a metal container 1 which is at ground potential, and the inside is compressed and filled with a gas 3 having excellent insulating performance such as SF6 gas at a predetermined gas pressure. A vibration detector 4 for detecting vibrations is attached to the outer wall of the metal container 1, and signals from the vibration detector 4 are sent to a receiver 6 via a cable 5.

From the detected signal of the above-mentioned motion detector 4-C, only signals in a specific frequency band are extracted by a bandpass filter 7.
The signal is amplified by a specific frequency band amplifier 8 which is capable of amplifying only signals in the frequency band passing through the bandpass filter, and then output.

(Problems to be Solved by the Invention) By the way, abnormalities within the metal container 1 include partial discharges in insulators, foreign metal objects, etc., and both of them are transmitted to the wall surface of the container as vibrations and sound waves. However, the vibration frequencies that occur are in front of both, and the partial discharge within the membrane is several tens of MHz.
In the z-band, metallic foreign objects are 100 Mt-1z or higher, but they also vary depending on the type and shape of the foreign object.Furthermore, the frequency of vibrations generated on the container surface also differs depending on the material and shape of the metal container. For this reason, when a system as shown in FIG. 3 is used, there is a drawback that a device is required for each detection target.

The present invention has been made in view of the above circumstances, and its object is to provide an excellent gas-insulated switchgear that detects multiple types of abnormalities by making some parts of the abnormality detection device easily replaceable. An object of the present invention is to provide an abnormality detection device.

[Structure of the invention]

(Means for Solving the Problems) The abnormality detection device for gas-insulated switchgear according to the present invention uses a broadband amplifier and is configured such that a bandpass filter that passes only vibration signals in a specific frequency band is easily replaceable. It is a feature.

(Function) In the present invention having the above configuration, the bandpass filter provided in the front stage of the broadband amplifier can be easily replaced, so that a single abnormality detection device can detect multiple types of internal abnormalities with different generation frequencies. becomes detectable.

Furthermore, grounded metal containers of various shapes can be measured with a single receiver by simply replacing the bandpass filter.

(Example) Hereinafter, an example to which the present invention is applied will be described based on FIG.

A high-voltage conductor 2 is arranged in a metal container 1 at ground potential, and a gas 3 with excellent insulation performance, such as SFe gas, is placed inside.
is compressed and filled at a predetermined gas pressure. A vibration detector 4 for detecting vibrations is attached to the outer wall of the metal container 1, and the signal from this is sent via a cable 5 to an easily replaceable bandpass filter 9 in a receiver 6 to detect a specific frequency. Only obi objects are detected. The signal that has passed through the bandpass filter 9 is amplified by a wideband amplifier 10 and output to the outside.

The operation of this embodiment having the above configuration is as follows.

Abnormalities inside the metal container 1 include partial discharge occurring in the insulators of the spacers that hold the high voltage conductor 2, etc., and the inclusion of metal foreign matter. It's coming through. These vibrations are detected by a vibration detector 4 and transmitted as electrical signals to a receiver 6 via a cable 5.

Incidentally, the frequency of vibrations generated on the wall surface of the metal container 1 differs depending on the type of abnormality. -When partial discharge occurs in the membrane, insulator, etc., the vibration frequency is several tens of MHz.
z band, and when metal foreign matter is mixed in, the frequency is set to be 100 MHz or more, although it varies depending on the type and shape of the foreign matter.

Therefore, it becomes possible to easily replace the sensor according to the frequency band of the object to be detected.

Matched coaxial cables are used to connect each module in the high frequency signal processing circuit as described above. Therefore, if such coaxial connectors are provided at both connection ends of the bandpass filter 9, the filter can be easily replaced.

As explained above, in this embodiment, by combining a broadband amplifier and an easily replaceable bandpass filter, a gas-insulated An abnormality detection device for a switchgear can be provided.

In addition, as shown in FIG. 2, a plurality of band-pass filters 11 for different frequency bands are provided in the receiver 6, and by switching the switch 12 using a switching signal from a distance, signals of different frequency bands can be automatically transmitted. That is, it becomes possible to detect a plurality of types of internal abnormalities with one abnormality detection device.

As mentioned above, coaxial cables are used to connect each module of such a detection circuit.

Therefore, if a general coaxial transmission line switch is used as the switch 12, the switch circuit as shown in FIG. By combining these bandpass filters, it is possible to provide an abnormality detection device for a gas-insulated switchgear that can detect a plurality of types of internal abnormalities with one abnormality detection device.

[Brief explanation of drawings]

Fig. 1 is a block diagram of an abnormality detection device for a gas insulated switchgear showing one embodiment of the present invention, Fig. 2 is a block diagram of an abnormality detection device showing another embodiment of the present invention, and Fig. 3 is a block diagram of a conventional FIG. 2 is a configuration diagram showing an abnormality detection device. DESCRIPTION OF SYMBOLS 1...Metal container, 2...High voltage conductor, 3...Gas, 4...Vibration detector, 5...Cable, 6...Receiver, 7...Band pass filter 8 ... Specific frequency band amplifier, 9 ... Replaceable band pass filter 10 ... Broadband amplifier, 11 ... Band pass filter 12 ... Switching device. Agent Patent Attorney Noriyuki Chika Ken Yudo Daikomaru Ken Figure 1-7'

Claims (2)

[Claims] (1) A device that is attached to the outer wall of a container containing a conductor charged to a high voltage and filled with insulating gas to detect vibrations of the container due to an abnormality within the container, which uses a broadband amplifier and An abnormality detection device for gas insulated switchgear characterized by an easily replaceable bandpass filter that allows only vibration signals in a specific frequency band to pass. (2) Abnormality in the gas-insulated switchgear according to claim 1, characterized in that a plurality of band-pass filters are installed to pass only vibration signals in a specific frequency band, and can be easily switched by a signal from a distance. Detection device.