JPH04127068A - Current transformer of optical meter for gas insulated switchgear - Google Patents

Abstract

PURPOSE:To suppress the output error of an optical current transformer accompanying the shift of the optical axis of an optical space transmission line by fixing an optical current transformer sensor detection part to the central part of a conical disc-shape insulating spacer and fixing a light emitting and detecting head to the wall surface of the hermetically closed container opposed to said head. CONSTITUTION:An optical current transformer glass sensor detection part 3 is fixed to the outer peripheral surface of the conductor connecting seat 24 fixed to one end surface of the conductor connection part 21 embedded in the through-hole 20a of the central part of a conical disc-shape insulating spacer 20 and a light emitting and detecting head 5 is fixed to the light emitting and detecting head cover 26 fixed to the opening part 1Bw formed to the wall surface of the container unit 1B opposed to said detection part 3. In this case, since a current supply contact element 25 flexibly comes into contact with a main circuit conductor 2B, the detection part 3 does not receive the effect of the mechanical vibration or stress generated in the conductor 2B. Since the spacer 20 is fixed to a hermetically closed container 1 by flanges 1Af, 1Bf, the optical space transmission shaft between the head 5 and the detection part 3 is strongly held and the output error of the detection part 3 accompa nying the shift of an optical axis can be suppressed. Further, since the special member supporting the detection part 3 is unnecessary, a structure is miniaturized and simplified.

Description

[Detailed Description of the Invention] [Purpose of the Invention (Industrial Application Field) The present invention is a current transformer for optical instruments that uses the Faraday effect, and detects the current transformer near the main circuit conductor of a gas-insulated switchgear. The present invention relates to a current transformer for an optical instrument for a gas-insulated switchgear that transmits optical information from a section to an insulating gas space in a closed container.

(Prior Art) Conventionally, as current transformers for optical instruments of this type for gas-insulated switchgear, the example shown in Fig. 3 (first example) and the example shown in Fig. 4 (second example) are described below. There is an example (third example) shown in FIG.

FIG. 3 shows a current transformer glass sensor detection unit 3 connected to a high voltage main circuit conductor 2 disposed in an insulating gas space S in a sealed container 1.
is supported by the glass sensor detection part holding seat 4, and the closed container 1 is located at a position facing the current transformer glass sensor detection part 3.
A light emitting/receiving head 5 is fixedly fixed to the wall surface of the housing. In this case, the light emitting light receiving head 5 and the current transformer glass sensor detection section 3
An optical space transmission line 6 is formed between the two. Note that 8 is a light emitting side optical fiber connected to the light emitting/receiving head 5 via the gas sealed fiber terminal 7, and 9 is a light receiving side optical fiber connected to the light emitting/receiving head 5 via the gas sealed fiber terminal 7. .

FIGS. 4 and 5 both show that in the configuration shown in FIG. 3, light due to optical axis deviation in the optical space transmission line 6 is strongly influenced by vibration of the switch provided in the gas-insulated switchgear. This is an example of a case where the current transformer is used in an application where an error is a problem. That is, FIG. 4 shows a tapered insulating cylinder 1.
The current transformer glass sensor detection unit 3 is held at one end of the insulating cylinder 10, and the other end of the insulating tube 10 is fixed to the inner wall surface of the closed container 1, thereby determining the relationship between the optical axes of the light emitting/receiving head 5 and the optical space transmission path 6. This is an example in which the value is not changed. In FIG. 5, a current transformer glass sensor detection unit 3 is held at one end of a hollow post-shaped insulating spacer 11, and the other end of the insulating spacer 11 is fixed to the inner surface of the airtight container 1 on the ground potential side. This is an example in which the relationship between the optical axes of 5 and the optical space transmission line 6 is not changed.

(Problems to be Solved by the Invention) In the example shown in FIG. 3, since the optical current transformer glass sensor detection unit 3 and the light emitting/receiving head 5 are installed so that the optical axes of the optical space transmission 6 coincide with each other, There are the following problems.

■The main circuit conductor 2 to which the sensor detection unit 3 is attached is bent due to vibrations caused by earthquakes and switch operation vibrations, and the optical axis between the light emitting/receiving head 5 and the sensor detection unit 3 is shifted, which causes the optical current transformer to An error occurs in the output.

■When a large fault current flows through the main circuit conductor 2, the main circuit conductor 2 is deflected by the electromagnetic mechanical force, and the light emitting/receiving head 5
The optical axis between the optical current transformer and the optical current transformer is shifted, which causes an error in the optical current transformer output.

(2) When attaching the sensor detecting section 3 to the main circuit conductor 2, it takes time and effort to adjust the optical axis between the sensor detecting section 3 and the light emitting/receiving head 5.

On the other hand, in FIGS. 4 and 5, the sensor detection section 3
is held at one end of the insulating cylinder 10 and the hollow post-shaped insulating spacer 11, and the other end is fixed to the inner wall surface of the closed container 1, which is a rigid body between the light emitting and receiving head 5, so that the light of the optical space transmission 6 is The shafts can be integrated, and the above-mentioned problem shown in FIG. 3 can be solved.

However, in FIGS. 4 and 5, in order to provide an optical current transformer consisting of a sensor detecting section 3 and a light emitting/receiving head 5, an insulating tube 10. Hollow post-shaped insulating spacers 11 must be provided. In addition, the insulating cylinder 10. In addition to providing the hollow post-type insulating spacer 11, in order to maintain creeping dielectric strength inside the sealed container 1, it is sufficient to ensure an insulation dimension L1 as shown in the figure between the sealed container l and the main circuit conductor 2. However, in order to install the optical current transformer, it is necessary to ensure an insulation dimension L2 that is longer than the insulation dimension L1, and for this reason, the external shape of the sealed container l in the part where the optical current transformer is actually inserted becomes larger. There is a problem.

Therefore, the present invention eliminates the output error of the optical current transformer due to the deviation of the optical axis of the optical space transmission line due to the increase in coil strength or the operation vibration of the switch. An object of the present invention is to provide a current transformer for an optical instrument for a gas-insulated switchgear, which does not require the provision of a hollow post-type insulating base, can be miniaturized as a whole, and can be simplified in configuration.

[Structure of the Invention (Means for Solving the Problems)] In order to achieve the above object, the present invention has a cylindrical airtight container filled with an insulating gas, and a main circuit conductor surrounded by a conical disc-shaped insulating spacer. It is electrically connected and mechanically supported by a conductor connection part in the center of the main circuit conductor, and is equipped with a light emitting light receiving head and an optical current transformer sensor detection part to measure the current flowing through the main circuit conductor, and has a magnetic field optical effect. In a current transformer for an optical instrument for a gas-insulated switchgear that can be measured with a charge current sensor that measures the magnetic field of a current to be measured using the Faraday effect, the optical current transformer sensor detection section is connected to the insulating spacer. The light emitting and light receiving head is attached to a conductor connecting portion provided at the center, and is configured to be fixed through the wall of the sealed container via an optical space transmission path at a position facing the optical current transformer sensor. It is.

(Function) According to the present invention, since the optical current transformer sensor detection section is directly fixed to the conical disc-shaped insulating spacer that supports the main circuit conductor, the optical current transformer sensor detection section and the light emitting/receiving head It is possible to eliminate the output error of the optical current transformer due to the optical axis misalignment of the optical space transmission between the optical current transformer and the optical current transformer sensor. There is no need to provide a shaped insulating spacer, so the overall size can be reduced and the configuration can be simplified.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal cross-sectional view showing only the essential parts of an embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along the line -■ in FIG. 1 and viewed in the direction of the arrow. Here, the same parts as in FIGS. 3 to 5 will be described with the same reference numerals. The gas insulated switchgear supports the main circuit conductor 2 and is provided with an insulating spacer 20 as shown in the figure for electrical connection. This insulating spacer 20 has a conical disk shape, and a conductor connection portion 21 is provided in a through hole 20a formed in the center of the insulating spacer 20.
is buried, and there are multiple bolt insertion holes 2 on the periphery.
0b is formed. For example, 2 constituting the airtight container 1
The container units IA and IB, which are each made up of cylindrical bodies, have flanges IAf and IBf formed at their ends, respectively. Bolt insertion holes IAfh, IBfh are formed at the positions, and the peripheral edge of the insulating spacer 20 is sandwiched between the flanges IAf, IBf, and these bolt insertion holes IAfh, IBfh, 20h
A bolt 22 is inserted into the bolt 20, and a nut 23 is screwed onto the protruding end of the bolt 20, whereby the container unit I
A.

The IB and the insulating spacer 20 are integrally connected.

Thus, a bottomed cylindrical conductor connection seat 24 is fixed or firmly attached to one end surface of the conductor connection portion 21 . A tapered portion 28a formed at the tip of the main circuit conductor 2B inside the conductor connection seat 24 is configured to be slidable in the axial direction, and the inner circumferential surface of the conductor connection seat 24 that contacts the outer circumferential surface of the tapered portion 28a has a A contact insertion groove 24a for inserting an annular current-carrying contact 25 is formed. A glass sensor detection section holding seat 4 is provided on the outer circumferential surface of the conductor connection seat 24, and the optical current transformer glass sensor detection section 3 is supported and fixed thereby.

An opening IBw is formed in the wall surface of the container unit IB facing the glass sensor detection 83, and this opening I
A light emitting/receiving head cover 26 is fixed to Bw, a light emitting/receiving head 5 is fixed to the light emitting/receiving head cover 26, a gas-sealed fiber terminal 7 is fixed therethrough, and a fiber terminal 7 of the light emitting/receiving head 5 is fixed to the sealed fiber terminal 7. A light emitting side optical fiber 8 and a light receiving side optical fiber 9 are inserted.

The ends of two main circuit conductors are fixed to the other end face of the insulating spacer 20.

With this configuration, the current-carrying contact 25 is only in flexible contact with the main circuit conductor 2B, so the glass sensor detection unit 3 is independent. Further, the insulating spacer 20 is attached to the flanges IAf, I of the container units IA, IB.
Since Bf is firmly fixed to the closed container 1, the optical space transmission axis relationship between the light emitting/receiving head 5 fixed to the closed container 1 and the glass sensor detection section 3 is firmly maintained.
It is possible to completely suppress output errors of the optical current transformer caused by variations in the amount of received light due to optical axis misalignment.

[Effects of the Invention] According to the present invention described above, the optical current transformer sensor detection section
Since it is directly fixed to the conical disc-shaped insulating spacer that supports the main circuit conductor, the output of the optical current transformer is caused by the optical axis misalignment of the optical space transmission between the optical current transformer sensor detection part and the light emitting/receiving head. Errors can be eliminated, and there is no need to provide an insulating tube or hollow post-shaped insulating spacer, which was previously required to support the optical current transformer sensor detection section, making the overall size smaller and the structure simpler. We can provide current transformers for optical instruments for gas-insulated switchgear that can be used in

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional view showing only the essential parts of an embodiment of the current transformer for optical instruments for gas-insulated switchgear according to the present invention, and Fig. 2 is a longitudinal cross-sectional view showing only the essential parts of an embodiment of the current transformer for optical instruments for gas-insulated switchgear of the present invention. 3 to 5 are cross-sectional views of essential parts showing different examples of conventional optical instrument current transformers for gas-insulated switchgear. DESCRIPTION OF SYMBOLS 1... Airtight container, 2... Main circuit conductor, 3... Optical current transformer glass sensor detection part, 5... Light emitting light receiving head, 6
2.・Optical space transmission line, 20... Insulating spacer, 21・
...Conductor connection part, 24...Conductor connection seat, 25... Current-carrying contactor applicant representative Patent attorney Takehiko Suzue Figure +1 Figures ~3

Claims (1)

[Claims] A cylindrical airtight container is filled with an insulating gas, and a main circuit conductor is electrically connected by a conductor connection portion provided at the center of a conical disk-shaped insulating spacer, and mechanically connected to the main circuit conductor. A photocurrent sensor includes a light emitting light receiving head and an optical current transformer sensor detection unit to measure the current flowing through the main circuit conductor, and measures the magnetic field of the current to be measured using the Faraday effect in the magnetic field optical effect. In the current transformer for an optical instrument for gas-insulated switchgear, the optical current transformer sensor detection section is attached to a conductor connection section provided at the center of the insulating spacer, and the light emitting and receiving head is connected to the light emitting and receiving head. An optical current transformer for an optical instrument for a gas-insulated switchgear, which is penetrated and fixed to a wall surface of the sealed container via an optical space transmission line at a position facing an optical current transformer sensor.