JP2501896Y2 - Connection - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a connector for an ultrasonic detector for detecting partial discharge used in gas-insulated power equipment.

B. Outline of the Invention The present invention aims to provide a connector for easily outputting the detection signal of the ultrasonic detector for detecting the partial discharge of the gas-insulated power equipment to the outside with a high S / N ratio. The ultrasonic wave to be detected by connecting the output line of the ultrasonic detector inserted into the container to the connector for the coaxial cable penetrating to the outside of the container and providing the pressure seal part and supporting the center conductor with the ultrasonic insulator interposed. Easily send signals to the outside without being affected by external noise.

C. Prior Art SF ₆ (sulfur hexafluoride) gas is widely used as an insulating medium for closed power equipment as a highly reliable insulating gas. As a means for detecting and predicting the insulation deterioration inside the closed type electric power equipment, a detecting means using ultrasonic waves has been provided in recent years.

This ultrasonic detection device generally detects ultrasonic vibration due to partial discharge generated inside the closed container and monitors the insulation state inside. FIG. 3 shows the structure of a partial discharge detection device provided in a gas-insulated switchgear (hereinafter referred to as GIS) that is a closed power device. The ultrasonic sensor 101 is closely attached to the tube wall 2 of the GIS1 container. Have been fixed. The detection signal of the ultrasonic sensor 101 is digitized by the detection unit 102 and the A / D conversion unit 103 provided in the subsequent stage, and the insulation state inside the GIS 1 processed by the CPU 104 is monitored.

Problems D. devised to be Solved However, ultrasonic signals ultrasonic sensor in this case partial discharge detection device detects are not necessarily detects the signal by corona discharge is a partial discharge, SF ₆ gas of Ultrasonic waves generated when particles collide with the container while jumping inside the container by an alternating electric field are detected.
Therefore, in the conventional detection device, when the GIS is installed outside, if wind and rain hits the container wall, it is detected as a noise signal. The detected signal value is often the same as the frequency band where the corona discharge sound in the GIS is transmitted to the container, and the signal amount is larger than the corona discharge detection level.

For this reason, the S / N ratio of the detection device decreases, and it may be difficult to detect the corona discharge that is the target of detection due to wind and rain, and the process of sending the detected signal is easily affected by external noise, and improvements are required. It was being done.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a connector for a coaxial cable that is not affected by noise due to the external environment and that can easily take out a detection signal.

E. Means for Solving the Problems The present invention provides a connector with a pressure seal portion, and connects the output line of the ultrasonic detector inserted inside the container to the connector for the coaxial cable that penetrates to the outside of the container. It is characterized in that it is provided with a seal portion and that the central conductor is supported by interposing an ultrasonic insulator.

F. Action By using the above means, the ultrasonic signal due to the partial discharge inside the container can be taken out to the outside without mixing the external noise signal by the coaxial cable connector and the insulating gas pressure inside the container is sealed. it can.

G. Embodiment Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. First, the configuration of this embodiment will be described. FIG. 1 is a diagram for explaining the configuration of the partial discharge detection device of the present embodiment, in which a power conductor 11 is arranged at the center of the pipeline 2 which is the container of GIS1, and the inside of the pipeline 2 is SF. ₆ gas 12 is enclosed. A hole 2a is formed in a part of the conduit 2, and an ultrasonic sensor 4 as an ultrasonic detector is inserted into the conduit 2. The ultrasonic sensor 4 is inserted into the hole 2a via an ultrasonic absorbing material 5 such as rubber, and a metallic shield 13 that electrically constitutes a shield is arranged on the outer periphery of the ultrasonic absorbing body. It is fixed to the outer wall of No. 2.

The opening of the body 13 is sealed by an insulating plate 6, and a coaxial cable connector (hereinafter referred to as BNC) 3 is provided through the insulating plate 6. The detection signal of the ultrasonic sensor 4 is connected to the BNC3 by the coaxial cable 10 and the BNC3
Is connected to the preamplifier 8 of the ultrasonic detection device provided outside the GIS 1 by the coaxial cable 10, and passes through the bandpass filter 9, the detection unit 102, the A / D conversion unit 103 in the subsequent stage of the preamplifier 8 and the ultrasonic wave is transmitted by the CPU 104. The detection signal of the sensor 4 is arithmetically processed.

FIG. 2 is an enlarged view showing the configuration of the BNC 3 in detail, (a) is a plan view, and (b) is a sectional view. The BNC 3 is arranged so as to penetrate through the insulating plate 6 that seals the opening of the body 13, and is located inside the GIS 1 and connected to the ultrasonic sensor 4 with a flange at one end.
3b is formed integrally with the metal case 3a. Flange 3b
A groove is formed on the inner surface of the, that is, the surface closely contacting the insulating plate 6,
An O-ring 7a, which is a pressure seal portion, is housed in the groove.
Further, a screw is threaded on one end located outside the insulating plate 6,
The BNC 3 is fixed to the insulating plate 6 by the nut 3e.

The center conductor 3d penetrating the inside of the BNC 3 is provided with an ultrasonic insulator 3c such as rubber and an O-ring 7b as a pressure seal portion between the inner wall of the metal case 3a, and its center position is determined.

The operation of this embodiment configured as described above will be described. When the partial discharge corona discharge phenomenon occurs in the conduit 2 of the GIS 1, the ultrasonic vibration generated in the SF ₆ gas is directly detected by the ultrasonic sensor 4 inserted through the hole 2a of the conduit 2 inside. The detection signal of the ultrasonic sensor 4 is input to the BNC 3 by the coaxial cable 10. The BNC 3 seals the SF ₆ gas pressure inside the pipeline 2 of the GIS 1 with the O-ring 7a, and also seals the SF ₆ gas pressure intruding along the central conductor 3d with the O-ring 7b to prevent the SF ₆ gas inside the pipeline 2. To completely seal.

Although the ultrasonic waves propagating to the conduit 2 are considered as noise, the ultrasonic sensor 4 is disposed inside the conduit 2 with the ultrasonic absorber 5 interposed therebetween, and is electrically shielded by the enclosure 13. Therefore, it is not affected by the ultrasonic signal transmitted to the conduit 2. In addition, the BNC3 seals SF ₆ gas pressure with two O-rings at the pressure seals,
Since an ultrasonic insulator is interposed between the center conductor 3d and
It is not affected by the ultrasonic signal in the conduit 2.

The BNC of this embodiment is used for GIS, but it is naturally used for other various gas-insulated power equipment.

H. Effect of the Invention As described above, the present invention provides the coaxial cable connector that connects the output line of the ultrasonic sensor inserted inside the container and penetrates the outside of the container with the pressure seal part and the ultrasonic Since the insulator is supported, firstly, the ultrasonic vibration inside the insulating gas can be directly and accurately detected without being affected by the noise such as the ultrasonic signal propagating to the container.

Secondly, since the coaxial cable connector itself has a gas sealing function, it is possible to easily attach it by screwing only by making a hole in the container, and since the coaxial cable can be used, the influence of external noise is small. can do.

[Brief description of drawings]

FIG. 1 is a diagram for explaining the configuration of the present embodiment, FIG. 2 is an enlarged view of the main parts of FIG. 1, and FIG. 3 is an explanatory diagram of an embodiment according to the prior art. 1 ... GIS (gas-insulated power equipment), 2 ... Pipe (container), 3 ... BNC (connector for coaxial cable), 3a ... Metal case, 3b ... Flange, 3c ... Insulator (super) Sound wave insulator), 3d ... Central conductor, 4 ... Ultrasonic sensor (ultrasonic detector), 7a, 7b ... O-ring (pressure seal part).

Claims (1)

(57) [Scope of utility model registration request] 1. A connector for an ultrasonic detector, which is disposed in a gas-insulated electric power device in which an electric power device is housed in a container in which an insulating gas is sealed, and which is inserted into the container in an ultrasonic detector connecting device for detecting partial discharge generated in the container. A connector for connecting the output line of the ultrasonic detector, which has a coaxial cable connector penetrating to the outside of the container, with a pressure seal portion, and a central conductor supported by an ultrasonic insulator interposed therebetween.