JPS6398567A - Optical axis shift preventing structure of gas insulating optical current transformer - Google Patents

Abstract

PURPOSE:To prevent not only the shift of an optical axis but also the effect of the electromagnetic force acting on a conductor or the operating vibration of a breaker, by elastically supporting a light emitting-receiving part mount member and the structure on the side of a tank through an elastic member. CONSTITUTION:A case 19 having an optical magnetic field sensor 16 fixed thereto and a plate 22 having a light emitting-receiving part 25 fixed thereto are fixed to and supported by an insulating cylinder 21 and, further, the plate 22 is elastically supported by a supporting container 27 through rubbers 39, 40 being elastic members. Therefore, even if an excessive electromagnetic force caused by the flow of an accident current through a conductor or the operating vibration of a breaker acts to vibrate the current transformer unit 41, the optical magnetic field sensor 16 and the light transmitting-receiving part 25 integrally vibrate since they are strongly bonded to the insulating cylinder 21 having high rigidity. As a result, no relative dispalacement occurs between the sensor 16 and the part 25, so that no shift of the optical axis is generated.

Description

Detailed Description of the Invention (Objective of the Invention) (Industrial Field of Application) The present invention relates to a gas-insulated optical current transformer, and particularly to a gas-insulated optical current transformer that is equipped with an optical magnetic field sensor and a detection device thereof, and that transmits light between them. The present invention relates to a structure for preventing optical axis deviation of a gas insulated optical current transformer having a configuration in which:

(Prior Art) Conventionally, a gas insulated current transformer used in a gas insulated switchgear has been configured with an iron core type current transformer core made by winding a coil around a silicon steel plate.

In this case, since the current transformer core is different, the support plate that supports it,
Insulating shields and the like also become quite large, making the equipment complex, large-sized, and heavy. In addition, since the current transformer core is cocoa and can only be used for one purpose, multiple cores are required for relays, measurements, etc., which not only causes the size to increase, but also increases the cost. .

In view of these shortcomings, measurement technology using optical fibers, which have excellent characteristics such as small diameter, insulation, non-induction, and environmental resistance, has recently attracted attention. Attempts are being made to construct vessels.

FIG. 4 shows an example of a gas-insulated optical current transformer using such an optical magnetic field sensor.

In the figure, conductors 2u to 2W are attached to an insulating spacer 3 provided in a tank 1, and an optical magnetic field sensor 7 is provided near the connection portion 4 so as to go around the conductors 2u to 2W.

As shown in FIG. 5, this optical magnetic field sensor 7 is made of glass such as lead glass that produces a Faraday rotation angle depending on the strength of the magnetic field, and includes a Faraday element 11 with a total reflection surface at each corner and a reflection mirror 12. The Faraday element is configured such that the transmitted light goes around the conductor 2v as shown by the optical path 13, and the optical path is reciprocated by the reflecting mirror 12, so that it is not affected by the external magnetic field. This makes it possible to measure magnetic fields with high precision and high sensitivity.

On the other hand, a gas-sealed terminal 5 is provided on the tank 1 at a position corresponding to the optical magnetic field sensor 7, and a lens,
A light emitting/receiving section consisting of a polarizer, analyzer, etc. is built-in. Light is spatially transmitted between the optical magnetic field sensor 7 and the light emitting/receiving section.

The operation of the optical current transformer constructed in this way is as follows.

That is, light guided from the optical transmitter of the detection device 10 disposed outside the tank 1 to the sealed terminal 5 via the optical fiber 8 becomes linearly polarized light at the light emitting/receiving section inside the sealed terminal 5 and is transmitted to the optical magnetic field sensor 7. Sent. When this light passes through the Faraday element 11, it becomes polarized at an angle corresponding to the magnitude of the magnetic field, and then is sent again to the light emitting/receiving section in the sealed terminal 5, and then passes through the optical fiber 9 to the detection device 10. Sent.

The light is then extracted as optical power by the optical receiver of the detection device 10, subjected to arithmetic processing, and converted into an output proportional to the magnitude of the arithmetic processing.

As described above, since the optical magnetic field sensor has excellent insulation properties, it can be placed near the conductors 2u to 2W, and the gas insulated current transformer can be significantly downsized and lightened. In particular, if specific numerical values are given, it is thought that the length will be reduced by about 20% and the diameter will be reduced by about 60%.

In addition, since optical magnetic field sensors can freely multiplex signals,
Unlike conventional methods, which have multiple cores for different applications,
Just by providing one sensor, it can be used for multiple purposes. Therefore, in this respect, it is possible to make the current transformer smaller and simpler, and the cost is also lower.

By the way, as a gas-insulated optical current transformer using such an optical magnetic field sensor, as mentioned above, an optical magnetic field sensor υ consisting of a Faraday element is installed on the high voltage conductor side, and a light emitting/receiving part is directly attached to the tank side. In addition to the one that spatially transmits (the former), an optical magnetic field sensor consisting of a Faraday element, polarizer, analyzer, lens, etc. is installed on the high-voltage conductor side, and this optical magnetic field sensor and a light emitting sensor installed on the tank side are installed. One possibility is to connect the light receiving section with an optical fiber and transmit the light using this optical fiber (the latter). However, in the latter case, since the optical fiber is placed in a high electric field area, there is a possibility of insulation failure if microvoids exist between the cladding and the outer sheath of the optical fiber, which poses problems in terms of insulation reliability. . On the other hand, the former type, which performs spatial transmission, does not have such drawbacks and has excellent insulation reliability. Therefore, from this advantage, a space transmission type gas insulated optical current transformer is considered more promising.

Note that the above configuration is the same for a single-phase current transformer.

(Problems to be Solved by the Invention) By the way, in the gas-insulated optical current transformer having the above-mentioned configuration, an optical magnetic field sensor is provided on the high-voltage conductor side, and a light emitting/receiving section is directly attached to the tank side. Since light is transmitted through space, optical axis misalignment between the two is likely to occur, and optical axis misalignment caused by electromagnetic force acting on the conductor, vibration from breaker operation, etc. can significantly change the received light intensity at the light emitting and receiving parts. This has the disadvantage of causing large measurement errors.

The present invention was proposed in order to solve the above-mentioned problems, and its purpose is to enable highly accurate measurement without being affected by electromagnetic force moving in a conductor or vibration from the operation of a circuit breaker. The object of the present invention is to provide a gas-insulated optical current transformer that is possible.

[Structure of the invention]

(Means for Solving the Problems) The optical axis shift prevention structure according to the present invention includes an optical magnetic field sensor disposed around or inside a conductor disposed inside a tank of a gas-insulated electrical device, and an optical magnetic field sensor disposed outside the tank. A light emitting/receiving section connected to the installed detection device via an optical transmission means is arranged at a position on the tank side corresponding to the optical magnetic field sensor, and the optical magnetic field sensor and the light emitting/receiving section are fixedly supported by an insulator. ,
A gas-insulated optical current transformer that uses spatial transmission as a light transmission means between these parts is characterized in that the light emitting/receiving part mounting member and the tank-side structure are elastically supported via an elastic member.

(Function) In the gas-insulated optical current transformer configured as described above, vibration isolation is achieved by elastically supporting the light emitting/receiving part number 1 component and the tank side components via the elastic member, and the optical magnetic field sensor This prevents optical axis misalignment between the light emitting/receiving part and the light emitting/receiving part, and prevents it from being affected by electromagnetic force moving in the conductor or the operational vibration of the breaker.

(Embodiment) An embodiment of the structure for preventing optical axis deviation of a gas insulated current transformer according to the present invention as described above will be specifically described with reference to FIGS. 1 to 3.

FIGS. 1A and 1B show an embodiment in which the optical axis misalignment prevention structure according to the present invention is applied to a gas-insulated single-phase optical current transformer.

In FIG. 1, a conductor 15 is disposed within a tank 14, and connection portions 15a and 15b are formed at both ends of the conductor for connection to adjacent conductors disposed within a gas insulated switchgear. A case 19, which also functions as a magnetic shield and an electric field shield, is attached approximately at the center of the conductor 15. This case 19 is case 19a1 lid 19
The b1 insulating ring 19G is composed of three parts, and among the two conductor penetrating parts of the case 19, one penetrating part has the conductor and the case 19a fixed by welding, and the other penetrating part has the insulating ring 19G and the lid 19b. case 19a through
The conductor is fixed to.

Further, an outlet portion 44 is formed in the tank 14, and the support container 27 is detachably fixed to the flange of this outlet portion with bolts. An insulating cylinder 21 for supporting the case 19 and the conductor 15 is provided between the support container 27 and the case 19 and is perpendicular to the conductor 15.

One end of the insulating cylinder 21 is fixed to the case 19 with a bolt, and the other end is fixed to the cover 22 with a bolt. This holder 22 is fixed to the support container 27 with stepped bolts 37 via rubber 39 and 40. The shape of the rubber 39.40 is shown in FIGS. 2(A) and 2(B).

The rubber 39 is arranged between the washer 38 and the cutter 22 for each stepped bolt, and the rubber 40 has a protrusion 42 on its surface to form a 414 structure that also has a gas sealing effect. It is used by disposing it between the flanges of 27.

Further, a gas sealing portion using O-rings 28 to 32 is provided at the connecting portion of each member to form an airtight integrated optical current transformer unit 1 to 41, and a tank 14 is installed in this unit 41.
It is filled with insulating gas such as SFe gas at the same pressure as the inside.

On the other hand, inside the case 19, a magneto-optical field sensor 16 made of a Faraday element goes around the conductor 15.
It is fixed by a support stand 18 so as not to come into contact with the. The optical magnetic field sensor 16 has a substantially square cross section and includes a total reflection surface, a reflection mirror, and the like.

In addition, holes 20 and 23 for light passage are formed in the opposing surfaces of the case 19 and the cover 22, which are disposed at opposing positions with a space in the insulating cylinder 21 interposed therebetween. Furthermore, within the support container 27, a light emitting/receiving section 25 consisting of a lens, a polarizer, an analyzer, etc. is fixed to the lens 22 by the supporting section 24, and the light emitting/receiving section 25 and the light input/output member 17 of the optical magnetic field sensor 16 are connected to each other. teeth,
114 are arranged so as to face each other on the optical axis of the optical path, and light is transmitted through the space within the insulating cylinder 21.

Further, the support container 27 is provided with a dense i51 terminal 26,
The light emitting/receiving section 25 and a detection device 36 provided outside the tank 14 are connected via this sealed terminal 26 by optical fibers 34 and 35 for transmitting and receiving light.

The operation of this embodiment having the above configuration is as follows. That is, a case 19 to which the optical magnetic field sensor 16 is fixed,
Since the light emitting/receiving part 25 is fixedly supported by the insulating tube 21, and the support container 27 is elastically supported by the rubber 39, 40, which is an elastic member,
Even if an excessive electromagnetic force acts when a fault current flows through the conductor 15 or the current transformer unit 41 is activated due to operation of a breaker, the optical magnetic field sensor 16 and the light emitting/receiving section 25 (Since it is firmly connected to the insulating cylinder 21, which has a higher rigidity, it vibrates as a unit. Therefore, since there is no relative displacement between the optical magnetic field sensor 16 and the light emitting/receiving section 25, the optical axis does not shift. .

Furthermore, in this embodiment, by providing the protrusions 42 on the surface of the rubber 40, a good gas sealing effect can be maintained even when the rubber 40 expands and contracts. In combination with the optical current transformer units 1 to 41, it is possible to airtightly integrate the optical current transformer units 1 to 41. It can protect the optical components inside. Here, if there is a low possibility that decomposition products of the insulating gas will be generated, the gas seal part using the O-rings 28 to 32 or the rubber 40 described above may be used.
It is also possible to omit the protrusion 42.

In this embodiment, a circular integral type optical magnetic field sensor is used, but the present invention can also be applied to a case where a small optical magnetic field sensor for point magnetic field measurement is used. In addition, in this embodiment, the present invention was applied to an optical current transformer unit that is detachable from a tank, but the present invention is not limited to application to such a 17Is configuration. It is also possible to directly fix the tank 14 to the tank 14 through an elastic member. Furthermore, the elastic member is not limited to rubber, and springs, bellows, etc. may also be used.

Figure 3 shows the optical axis deviation prevention structure according to the present invention
This figure shows an example of a phase-optical current transformer.

In this embodiment, the gas-insulated single-phase optical current transformer shown in FIG. 1 is used, except that the tank 43 is of a three-phase type in which three optical current transformer units 41 are arranged inside. This embodiment has the same structure as the embodiment, and its operation and effect are also the same.

(Effects of the Invention) As explained above, according to the present invention, it is possible to provide high dielectric strength through spatial transmission of light, and to avoid being affected by electromagnetic shear acting on the conductor, operational vibration of a circuit breaker, etc. A gas insulated optical current transformer capable of highly accurate measurement can be provided.

[Brief explanation of the drawing]

FIGS. 1(A) and 1(B) are a cross-sectional view and a longitudinal sectional view, respectively, showing an embodiment in which the optical axis deviation prevention structure according to the present invention is adopted in a gas-insulated single-phase optical current transformer, and FIG. ). (8) is a front view and a sectional view showing the shape of the rubber used in the embodiment shown in Fig. 1, respectively, and Fig. 3 is a gas-insulated three-phase optical current transformer using the optical axis misalignment prevention structure according to the present invention. FIG. 4(8)(B) is a cross-sectional view showing one embodiment adopted, and FIG. FIG. 5 is a perspective view showing the configuration of an optical magnetic field sensor used in the gas insulated optical current transformer of FIG. 4. DESCRIPTION OF SYMBOLS 1...Tank, 2u~2w...Conductor, 3...Insulating spacer, 4...Connection part, 5...Sealed terminal, 6...
・Window, 7... Optical magnetic field sensor, 8.9... Optical fiber, 10... Detection device, 11
...Faraday element, 12...Reflection mirror, 13.
... Optical path, 14... Tank, 15... Conductor, 15a
, 15b... Connection portion, 16... Optical magnetic field sensor, 17
...First entry/exit surface, 18...Support stand, 19...Case, 19a...Case, 19b...Lid, 19c...
・Insulation ring, 20...hole, 21...insulation tube, 22
... Ita, 23... Hole, 24... Support part, 25.
...Light emitting and receiving section, 26... Sealed terminal, 27... Support container, 28-33... O-ring, 34.35... Optical fiber, 36... Detection device, 37... Stepped Bolt, 38...Washer, 39, 40...Rubber, 41...
- Optical current transformer unit, 42...Protrusion, 43...Tank, 44...Outlet part. Agent Patent Attorney Yudo Nori Chika Hirofumi MitsumataFigure 1 CA) 1-4 (β) RO = 24- is Figure 2 (A) Figure 2 (β. Figure 3 Figure 4 Cloud 5 figure

Claims (4)

[Claims] (1) A light emitting/receiving section in which an optical magnetic field sensor is installed around or inside a conductor installed in a tank of a gas-insulated electrical device, and is connected to a detection device installed outside the tank via an optical transmission means. is arranged at a position on the tank side corresponding to the optical magnetic field sensor, and the optical magnetic field sensor and the light emitting/receiving part are fixedly supported by an insulator, and the optical transmission means between them is a gas that performs spatial transmission. In an insulated optical current transformer, by elastically supporting the light emitting/receiving part mounting member and the components on the tank side via an elastic member, external mechanical vibrations are absorbed and the optical magnetic field sensor and the light emitting/receiving part are A structure for preventing optical axis deviation of a gas insulated optical current transformer, which is characterized by preventing optical axis deviation between. (2) An optical current transformer unit is constructed by elastically supporting a conductor, an optical magnetic field sensor, an insulating tube, and a light emitting/receiving section via an elastic member in a support container provided with an optical fiber sealed terminal, and this support container is A structure for preventing optical axis deviation of a gas insulated optical current transformer according to claim 1, characterized in that the structure is detachably fixed to a tank. (3) A structure for preventing optical axis deviation of a gas-insulated optical current transformer according to claim 1, characterized in that rubber is used as the elastic member. (4) Preventing optical axis deviation of the gas-insulated optical current transformer according to claim 3, characterized in that the elastic member also has a gas sealing effect by providing a protrusion on the surface, etc. structure.