JPH10142265A - Optical current transformer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical current transformer which can be miniaturized in a simple structure even in the case of a three phase one batch type gas insulating apparatus, and can carry out accurate current measurement without the influence of an current flowing in another phase applied current conductor. SOLUTION: An optical current transformer is equipped with three optical fibers 14a, 14b, 14c which are annularly wound on each periphery of three applied current conductors 3a, 3b, 3c and led out from a tank 1 at each both ends, a luminous section 9a for making a linear polarized light incident on the above optical fibers, and measuring sections 10a, 10b, 11a which detect an outgoing light emitted from the above optical fibers and measure an electric current flowing in the above applied current conductors on a polarized light state resulting from the Faraday effect of passing light.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas-insulated device filled with an insulating gas and having a three-phase current-carrying conductor.
The present invention relates to an optical current transformer for measuring a current flowing through a current-carrying conductor.

[0002]

2. Description of the Related Art As a method of measuring a current flowing through a current-carrying conductor of a gas insulating device, there is a method using an optical current transformer in addition to a method using a winding. FIG. 9 shows an example of a configuration using a conventional optical current transformer. A similar configuration of an optical current transformer is disclosed in, for example, Japanese Patent Application Laid-Open No. 61-70468.

In FIG. 9, the inside of a cylindrical gas insulating tank 1 is filled with an insulating gas 2,
The current-carrying conductor 3 is provided so as to extend in the axial direction.
An annular iron core 4 made of a magnetic material such as a silicon steel plate is provided so as to surround the current-carrying conductor 3. A part of the iron core 4 in the circumferential direction is cut to provide a gap. An optical magnetic field sensor 5 is provided in the gap. The optical magnetic field sensor 5
It is optically connected to a light emitting section 9 having a light emitting element such as a laser diode and a light receiving section 10 having a light receiving element such as a photodiode. An optical connector 6 is provided at a portion of the gas insulating tank 1 facing the optical magnetic field sensor 5. The optical magnetic field sensor 5 and the light emitting section 9 are connected via optical connectors 6 by optical fibers 7a and 7b for transmitting light. The optical magnetic field sensor 5 and the light receiving section 10 are connected via optical connectors 6 by light receiving optical fibers 8a and 8b.

Next, the operation will be described. The light emitted from the light emitting unit 9 is guided by the light transmitting optical fiber 7b, the optical connector 6, and the light transmitting optical fiber 7a, and is incident on the optical magnetic field sensor 5. The light emitted from the optical magnetic field sensor 5 is incident on the light receiving unit 10 via the light receiving optical fiber 8a, the optical connector 6, and the light receiving optical fiber 8b. The light detected by the light receiving unit 10 is converted into an electric signal, processed by the signal processing circuit 11, and then output from the secondary output terminal 12 to the outside of the device.

When a current flows through the current-carrying conductor 3, a magnetic field having a magnitude proportional to the current flows in the gap between the iron cores 4 and is applied to the optical magnetic field sensor 5. Here, the light emitted from the optical magnetic field sensor 5 receives a modulation proportional to the magnetic field generated in the gap between the iron cores 4, that is, the current flowing through the current-carrying conductor 3. This modulation is detected by the light receiving unit 10 and passes through the signal processing circuit 11,
It is output from the secondary output terminal 12 to the outside. This output is proportional to the magnitude of the current flowing through the current-carrying conductor 3.
That is, with this configuration, the magnitude of the current flowing through the current-carrying conductor 3 can be measured.

The optical magnetic field sensor 5 is composed of a Faraday element, a polarizer, an analyzer, and the like. The operation of these is already known, and the description thereof is omitted here.

[0007]

The conventional optical current transformer is constructed as described above. Since the iron core 4 is large, the diameter of the gas insulated tank 1 in which the optical current transformer is disposed is small. Since the optical magnetic field sensor 5 and the iron core 4 must be supported, the supporting structure in the gas insulated tank 1 becomes complicated, and the weight of the iron core 4 is large, so that the supporting structure is robust. Needed. Further, in a three-phase package type gas insulated device having three-phase current-carrying conductors, three sets of the above-described structures are required, and there is a problem that the size is further complicated and increased.

When three sets of optical current transformers are used in a three-phase package type gas insulated device, the current flowing through the current-carrying conductors of the other phases is affected by a magnetic field formed by the current transformers, and the optical current transformer of its own phase is not affected. There was a problem that the measurement accuracy of the instrument was reduced.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is possible to reduce the size of a three-phase gas-insulated apparatus with a simple structure and to flow through a current-carrying conductor of another phase. It is an object of the present invention to obtain an optical current transformer capable of measuring current with high accuracy without being affected by current.

[0010]

According to a first aspect of the present invention, there is provided an optical current transformer wherein three current-carrying conductors are wound around the inside of the tank in a ring shape, and both ends of the three current conductors are led out of the tank. An optical fiber, connected to one end of each optical fiber, a light emitting unit for inputting linearly polarized light to the optical fiber, and connected to the other end of each optical fiber, to detect light emitted from the optical fiber, A measurement unit that measures a current flowing through the current-carrying conductor based on a polarization state of the light passing through the optical fiber due to the Faraday effect.

In the optical current transformer of the present invention, the three current-carrying conductors are arranged at regular intervals in a plane perpendicular to the axis of the tank, and each of the three optical fibers has a winding start,
The winding ends and the leading-out directions of both ends are arranged in a plane perpendicular to the axis of the tank in a direction opposite to the centers of the three current-carrying conductors.

According to a third aspect of the present invention, the optical current transformer is annularly wound around the three current-carrying conductors inside the tank, and both ends are connected to an optical fiber extending from the tank and one end of the optical fiber. , A light emitting unit for inputting linearly polarized light to the optical fiber, and connected to the other end of the optical fiber, detecting emitted light emitted from the optical fiber, and changing the polarization state accompanying the Faraday effect of light passing through the optical fiber. And a measuring unit for measuring a current flowing through the current-carrying conductor based on the measurement.

[0013] In the optical current transformer according to claim 4, the tank is constituted by connecting a plurality of cylindrical bodies having flanges at both ends by connecting the flanges to each other, and between the two connected flanges. It has a plate-shaped insulating support member that is sandwiched and supported and has a through-hole formed therein, the current-carrying conductor is supported by the insulating support member through the through-hole, and the optical fiber is embedded and distributed in the insulating support member. Has been established.

In the optical current transformer according to a fifth aspect, the tank is constituted by connecting a plurality of cylindrical bodies having flanges at both ends by connecting the flanges to each other, and connecting the two flanges to each other. It has a plate-shaped support member that is sandwiched and supported, and has a through-hole larger in diameter than the current-carrying conductor, the current-carrying conductor penetrates the through-hole so as not to contact the support member, and the optical fiber The main surface is wound and disposed along a groove formed in an annular shape around the through hole.

In the optical current transformer according to a sixth aspect of the present invention, a buffer is provided around the optical fiber.

According to a seventh aspect of the present invention, a partition is provided in the tank, the partition being electrically connected to the tank and separating the optical fiber wound around the current-carrying conductor from other current-carrying conductors.

In the optical current transformer according to the present invention, the optical fiber led out of the tank is disposed so as to pass through a conductive cylinder connected to the optical fiber lead-out portion of the tank.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. FIG. 1 is a sectional view of a gas insulated equipment tank showing an optical current transformer of the present invention. FIG. 2 is an axial sectional view of the gas-insulated equipment tank. In FIG. 1, an insulating gas 2 is filled in a cylindrical gas insulating device tank 1 as a tank. In the gas-insulated equipment tank 1, three current-carrying conductors 3a, 3b, and 3c through which one-phase currents flow and three-phase currents as a whole extend and extend in the axial direction of the gas-insulated equipment tank 1. Have been. Three current-carrying conductors 3a, 3
b and 3c are arranged at equal intervals in a plane perpendicular to the axis of the gas-insulated equipment tank 1. The centers of the three current-carrying conductors 3a, 3b, 3c coincide with the center of the gas-insulated equipment tank 1. That is, the three current-carrying conductors 3a, 3b, 3c are arranged at positions corresponding to the vertices of an equilateral triangle with the center axis of the gas-insulated equipment tank 1 as the center.

Inside the gas-insulated equipment tank 1, three detection optical fibers 14a, 14b, 14c wound in an annular shape around each of the current-carrying conductors 3a, 3b, 3c, respectively.
Are arranged. The winding start and the winding end are arranged on a side perpendicular to the axis of the gas-insulated equipment tank 1 on the side opposite to the center of the gas-insulated equipment tank 1. Both ends of each detection optical fiber 14a, 14b, 14c are led out through optical fiber outlets 15a, 15b, 15c, respectively. Then, the lead-out direction is arranged so as to lead radially from the center of the gas-insulated equipment tank 1. That is, each detection optical fiber 14a,
The leading-out directions of both ends of 14b and 14c are arranged such that the angle θ ゜ formed in the circumferential direction around the axis of the gas-insulated equipment tank 1 is 120 degrees. Detection optical fiber 14a,
Reference numerals 14b and 14c not only allow the light to pass therethrough but also have a Faraday effect, and have a function of changing the polarization state of the light passing through the optical fiber by the magnetic field formed by the current.

One of the two ends of the detection optical fiber 14a led out of the gas-insulated equipment tank 1 passes through the lens 17a, the polarizer 16, and the lens 17b, and is then connected to the light emitting section 9a by the light transmission optical fiber 7c. Optically connected. The other side is split by the beam splitter 13 after passing through the lens 18a. One side passes through the analyzer 19a and the lens 18b to the light receiving unit 10a by the light receiving optical fiber 8c, and the other side passes through the analyzer 19b. Lens 18
The optical fiber is optically connected to the light receiving section 10b via the light receiving optical fiber 8d via the line c. Two light receiving units 10a and 10b
Are electrically connected to the signal processing circuit 11a. Light receiving units 10a and 10b and signal processing circuit 11a
Constitutes a measuring unit for measuring a current flowing through the current-carrying conductor 3a. The signal processing circuit 11a is externally connected to the secondary output terminal 1
Two. Although not shown, the detection optical fibers 14b and 14c have the same lenses, polarizers, light transmission optical fibers, light reception optical fibers, and light emission as those connected to the detection optical fibers 14a, respectively. Section, light receiving section,
The signal processing circuit and the secondary output terminal are connected.

Referring to FIG. 2, current-carrying conductors 3a, 3b, 3c
The structure for supporting the detection optical fibers 14a, 14b, 14c will be described. As shown in FIG. 2, the gas-insulated equipment tank 1 has a substantially cylindrical shape and has flange portions 1b at both ends.
Are connected to each other by connecting the flange portions 1b to each other. Between the two flange portions 1b to be connected, a three-phase insulating spacer 20 made of an insulating material such as epoxy, which is a substantially disk-shaped insulating supporting member, is disposed with its peripheral portion being narrowly attached. . Three through-holes 20 a are formed in the three-phase insulating spacer 20. Three conducting conductors 3a, 3b, 3 through which a three-phase current flows
c are respectively penetrated through the through holes 20a, and are insulated and supported from the gas-insulated equipment tank 1. The three-phase insulating spacer 20 separates the inside of the gas-insulated equipment tank 1 into a plurality of rooms,
Each room is sealed. And the conducting conductor 3a
The detection optical fiber 14a arranged so as to surround
It is embedded and supported in the three-phase insulating spacer 20. The detection optical fiber 14a is led out from the outer peripheral end of the three-phase insulating spacer 20, and is connected to the optical fiber outlet 1
5a. Although not shown, the detection optical fibers 14b and 14c have the same structure.
The three-phase insulating spacer 20 is embedded in the three-phase insulating spacer 20 so as to surround the other-phase current-carrying conductors 3b and 3c, respectively.

Next, the operation will be described. The light emitted from the light emitting section 9a passes through the light transmitting optical fiber 7c and passes through the lens 17b.
, And is converted into a parallel beam by the lens 17b, and then converted by the deflector 16 into linearly polarized light. Thereafter, the light incident on the optical fiber for detection 14a by the lens 17a is guided into the gas insulated equipment tank 1 through the optical fiber outlet 15a. The light is modulated by a magnetic field formed by a current flowing through the current-carrying conductor 3a while passing through the detection optical fiber 14a. The light modulated by the detection optical fiber 14a passes through a lens 18a, is separated into two components orthogonal to each other by a beam splitter 13, and is separated by an analyzer 19
a, It is incident on the analyzer 19b. Further, the analyzer 19a,
The light emitted from the analyzer 19b enters the light receiving optical fibers 8c and 8d by the lenses 18b and 18c, is guided by the light receiving optical fibers 8c and 8d, and is received by the light receiving units 10a and 10d.
At 0b, it is converted into an electric signal. This electric signal is calculated by the signal processing circuit 11a, and then the secondary output terminal 12
It is output as a signal. This signal is supplied to the conducting conductor 3a.
Is proportional to the current flowing through. Similarly, a signal proportional to the current flowing through the current-carrying conductors 3b and 3c is output to the other two secondary output terminals.

Detection optical fibers 14a, 14b, 14c
Forms a complete closed loop, the Faraday effect is proportional to only the current flowing through the current-carrying conductor in its own phase from Ampere's law. However, in actuality, it is difficult to completely match the winding start and end portions of the detection optical fiber 14a in consideration of the allowable bending radius and the like of the optical fiber. This part is most susceptible to the current flowing through the other phase conducting conductor. Therefore, in the configuration of the present invention, the winding start and end portions of the detection optical fiber are arranged so as to be farthest from the current-carrying conductor of the other phase. By doing so, the portion that is not closed loop becomes farthest from the current-carrying conductor of the other phase, and the effect of the current flowing through the current-carrying conductor of the other phase can be reduced.

In the optical current transformer having such a configuration, each of the current-carrying conductors 3a, 3
Since only three detection optical fibers 14a, 14b, and 14c wound in an annular shape around b and 3c, respectively, it is sufficient to reduce the size with a simple structure. In addition, since the winding start and end portions of the detection optical fibers 14a, 14b, and 14c are arranged farthest from the other-phase current-carrying conductor, the influence of the current flowing through the other-phase current-carrying conductor can be reduced. Can be. Therefore, highly accurate current measurement becomes possible.

In the optical current transformer having such a configuration, the detection optical fibers 14a, 14b, 14c are embedded in an insulating member for supporting the current-carrying conductors 3a, 3b, 3c. The detection optical fibers 14a, 14b,
The detection optical fibers 14a, 14b, and 14c can be supported with a simple configuration without requiring a new member for supporting the detection optical fibers 14c.

In the present embodiment, the leading directions of both ends of each of the detection optical fibers 14a, 14b, 14c are as follows.
It is optimally arranged that the angle θ ゜ formed in the circumferential direction around the axis of the gas-insulated equipment tank 1 is 120 degrees. However, due to the structure of the support member and manufacturing errors,
It is difficult to reach 20 degrees. In this case, in the range of ± 20 °, the current flowing through the other phase is hardly affected. And it is known that in the range beyond that, it is suddenly affected. In other words, there is no problem in the direction in which both ends of each of the detection optical fibers 14a, 14b, and 14c are led out, as long as the angle?

Embodiment 2 FIG. FIG. 3 is an axial sectional view of a gas insulated equipment tank showing another example of the optical current transformer of the present invention. In the first embodiment, the detection optical fibers 14a, 14
The b and 14c are embedded and supported in the three-phase insulating spacer 20, but in the present embodiment, as shown in FIG. 3, between the two flange portions 1b to be connected, A substantially disk-shaped support member 21 made of metal, which supports the detection optical fibers 14a, 14b, and 14c, is disposed with its peripheral portion being narrowly attached.

The support member 21 has three current-carrying conductors 3a, 3b, 3c through which a three-phase current flows, and
Three circular holes 22a are provided which are large enough to secure an insulation distance between the support members 21a, 3b and 3c. The current-carrying conductor 3a penetrates the center of the hole 22a, and a sufficient gap is provided between the current-carrying conductor 3a and the support member 21 to ensure insulation between the two. On the main surface of the support member 21, a groove 23a is formed along the edge around the circular hole 22a. The detection optical fiber 14a is wound in the groove 23a. The detection optical fiber 14a is guided to the outside via an airtight through connector 15d. Similarly, the current-carrying conductors 3b and 3c also pass through the circular holes 22a, and grooves 23a are formed around the holes 22a, and the detection optical fibers 14b and 14c are wound in the grooves 23a. Have been.

The three current-carrying conductors 3a, 3b, 3c are
The three-phase insulating spacer 20 of the first embodiment, which is provided at another place, is supported by a general three-phase insulating spacer having a structure having no detection optical fiber. As in the first embodiment, the three-phase insulating spacer 20 divides the inside of the gas-insulated equipment tank 1 into a plurality of rooms and seals each room.

The optical current transformer having such a configuration has the support member 21 in which three large-diameter holes 22a through which the current-carrying conductors 3a, 3b and 3c can penetrate without contacting each other are formed. The detection optical fibers 14a, 14b, 14c are wound around grooves 23a formed around each hole 22a.
For this reason, the optical fibers 14a, 14b, and 14c can be provided in places where the three-phase insulating spacers are not provided. In addition, the support member 21 is not limited to metal and may be a conductive material. Since the support member 21 has a simple structure and does not select a material, it can be manufactured at low cost.

Embodiment 3 FIG. 4 is an enlarged cross-sectional view of a main part in the axial direction of a gas insulated equipment tank showing another example of the optical current transformer of the present invention. This embodiment is substantially the same as the second embodiment. On the main surface of the support member 21, there are formed holes 22a through which the current-carrying conductor 3a can pass without contact, and around each hole 22a, a groove is formed. The detection optical fiber 14a is accommodated therein, and a buffer 24 such as silicone rubber is filled around the detection optical fiber 14a in the groove 23a. Other configurations are the same as those of the second embodiment.

The detection optical fiber 14a is affected by external stress such as vibration, which may reduce the measurement accuracy of the current flowing through the current-carrying conductor. Since the material 24 is filled, the influence of external stress such as vibration can be reduced. And
A decrease in measurement accuracy due to stress can be eliminated.
In the present embodiment, the detection optical fibers 14a, 14a
Although the buffer material 24 is filled around the b and 14c, the buffer material 24 in which a groove is formed in advance so that the detection optical fibers 14a, 14b and 14c can be easily housed is disposed, and then the detection is performed in this groove. Optical fibers 14a, 14b, 14c may be arranged.

Embodiment 4 FIG. FIG. 5 is a sectional view of a gas insulated equipment tank showing another example of the optical current transformer of the present invention. FIG.
As shown in FIG. 7, in the present embodiment, similarly to the first embodiment, the gas-insulated equipment tank 1 has a ring 3 wound around each of the current-carrying conductors 3a, 3b, and 3c. The detection optical fibers 14a, 14b, and 14c are provided. Further, each detection optical fiber 14
A metal plate 25, which is a partition wall provided so as to separate a, 14b, and 14c, is provided. The metal plate 25 is provided with a predetermined length in the axial direction of the gas-insulated equipment tank 1 so that each of the detection optical fibers 14a, 14b, and 14c is not affected by a magnetic field from another current-carrying conductor. Have been. The metal plate 25 is grounded to the same potential as the gas-insulated equipment tank 1 so as not to have a floating potential. Other configurations are the same as those of the first embodiment.

In the optical current transformer configured as described above, for example, the magnetic field formed by the current flowing through the current-carrying conductors 3b and 3c is canceled out by the overcurrent induced in the metal plate 25, and the detection optical fiber 14a It does not affect the place where it is mounted, and the influence of the current flowing through the current-carrying conductor of the other phase is reduced. Therefore, the influence of the current flowing through the current-carrying conductor of the other phase can be further reduced.

Embodiment 5 FIG. FIG. 6 is an enlarged cross-sectional view of a main part of a gas insulated equipment tank in an axial direction showing another example of the optical current transformer of the present invention. FIG. 7 is a sectional view taken along the line VII-VII in FIG. In this embodiment, as shown in FIGS. 6 and 7, the periphery of the detection optical fiber 14 a led out of the gas-insulated equipment tank 1 is covered with a metal tube 26. The metal tube 26 has a flange 26a formed at the end.
Is coupled to and attached to a flange portion 1c formed at a lead-out portion of the detection optical fiber 14a. An insulating member 1 having airtightness is provided between the two flange portions 1c and 26a.
5d is provided. Inside the metal tube 26, the detection optical fiber 14a is entirely covered with a buffer material 24a so that external stress such as vibration is reduced.

In the optical current transformer configured as described above, when a current flowing through the current-carrying conductor is grounded to the gas-insulated equipment tank 1, a ground-fault current also flows to the gas-insulated equipment tank 1, and Although the detection optical fiber 14a in the portion drawn out of the equipment tank 1 is also affected by this ground fault current, in the present embodiment, the periphery of the detection optical fiber 14a is covered with the metal tube 26. Therefore, it is possible to prevent the influence of the ground fault current. In a multi-phase grounded three-phase gas-insulated device, the jacket current flows through the gas-insulated device tank 1 even during normal operation. However, the influence can be prevented. That is, the influence of the current flowing through the gas insulating tank 1 can be eliminated.

Embodiment 6 FIG. FIG. 8 is a sectional view of a gas insulated equipment tank showing another example of the optical current transformer of the present invention. In the present embodiment, as shown in FIG.
One detection optical fiber 14d wound around all of a, 3b, and 3c is arranged. And
Although not shown, the detection optical fiber 14d includes the same lens, polarizer, light transmitting optical fiber, light receiving optical fiber, and light emitting element as those connected to the detection optical fiber 14a of the first embodiment. Section, a light receiving section, a signal processing circuit, and a secondary output terminal. Then, the detection optical fiber 1
Reference numeral 4d denotes a substantially disk-shaped insulating spacer made of an insulating material such as epoxy, which is an insulating support member that penetrates and supports the current-carrying conductors 3a, 3b, and 3c. It is supported.

In the optical current transformer configured as described above, the detecting optical fiber 14d is connected to all the current-carrying conductors 3d.
a, 3b, and 3c are wound around the conductors 3a, 3b, and 3c.
That is, the zero-phase current is detected. Current-carrying conductors 3a,
When the current flowing through each of 3b and 3c is individually measured, the configuration of the first to sixth embodiments must be used. However, when measuring the zero-sequence currents, the present configuration can achieve a smaller size than the sum of the secondary currents measured individually.

The detection optical fiber 14d is formed on the main surface of a support member 21 having a large-diameter through hole 22a through which the current-carrying conductors 3a, 3b, and 3c pass without contact, substantially in the same manner as in the second embodiment. It may be embedded in the formed groove 23a.

[0040]

According to the optical current transformer of the present invention, three optical fibers wound annularly around each of the three current-carrying conductors inside the tank, and both ends of which are led out of the tank, are provided. A light-emitting unit connected to one end of each optical fiber and for inputting linearly polarized light to the optical fiber; and a light-emitting unit connected to the other end of each optical fiber to detect light emitted from the optical fiber and to pass through the optical fiber. A measuring unit for measuring a current flowing through the current-carrying conductor based on a polarization state of the light passing therethrough due to the Faraday effect. Therefore, the portion of the optical current transformer provided inside the tank can be reduced in size with a simple structure.

In the optical current transformer according to the second aspect, the three current-carrying conductors are arranged at equal intervals in a plane perpendicular to the axis of the tank, and each of the three optical fibers has a winding start,
The winding ends and the leading-out directions of both ends are arranged in a plane perpendicular to the axis of the tank in a direction opposite to the centers of the three current-carrying conductors. Therefore, the influence of the current flowing through the current-carrying conductor of the other phase can be reduced, and highly accurate current measurement can be performed.

According to a third aspect of the present invention, the current transformer is annularly wound around the three current-carrying conductors inside the tank, and both ends are connected to an optical fiber extending from the tank and one end of the optical fiber. , A light emitting unit for inputting linearly polarized light to the optical fiber, and connected to the other end of the optical fiber, detecting emitted light emitted from the optical fiber, and changing the polarization state accompanying the Faraday effect of light passing through the optical fiber. And a measuring unit for measuring a current flowing through the current-carrying conductor based on the measurement. In the case of detecting the total value of the currents flowing through the current-carrying conductors, that is, the zero-phase current, the size can be reduced with a simple configuration.

In the optical current transformer according to claim 4, the tank is constituted by connecting a plurality of cylindrical bodies having flanges at both ends by connecting the flanges to each other, and connecting the two flanges to each other. It has a plate-shaped insulating support member that is sandwiched and supported and has a through-hole formed therein, the current-carrying conductor is supported by the insulating support member through the through-hole, and the optical fiber is embedded and distributed in the insulating support member. Has been established. Therefore, the optical fiber is supported by an insulating support member that supports the current-carrying conductor,
The optical fiber can be supported with a simple configuration without requiring a new member for supporting the optical fiber.

In the optical current transformer according to the fifth aspect, the tank is formed by connecting a plurality of cylindrical bodies having flanges at both ends by connecting the flanges to each other, and between the two connected flanges. It has a plate-shaped support member that is sandwiched and supported, and has a through-hole larger in diameter than the current-carrying conductor, the current-carrying conductor passes through the through-hole so as not to contact the support member, and the optical fiber The main surface is wound and disposed along a groove formed in an annular shape around the through hole. Therefore, the support member has a simple structure and can be manufactured at low cost because the material is not selected.

In the optical current transformer according to the sixth aspect, a buffer member is provided around the optical fiber. Therefore, the influence of external stress such as vibration can be reduced, and a decrease in measurement accuracy due to the stress can be removed, so that more accurate current measurement can be performed.

In the optical current transformer according to the present invention, a partition is provided in the tank, the partition being electrically connected to the tank and separating the optical fiber wound around the current-carrying conductor from other current-carrying conductors. Therefore, the influence of the current flowing through the current-carrying conductor of the other phase is further reduced, and more accurate current measurement can be performed.

In the optical current transformer according to the present invention, the optical fiber led out of the tank is disposed so as to penetrate a conductive cylinder connected to the optical fiber lead-out portion of the tank.
Therefore, the effect of the current flowing through the tank can be removed, and more accurate current measurement can be performed.

[Brief description of the drawings]

FIG. 1 is a sectional view of a gas insulated equipment tank showing an optical current transformer of the present invention.

FIG. 2 is an axial sectional view of a gas-insulated equipment tank.

FIG. 3 is an axial sectional view of a gas-insulated equipment tank showing another example of the optical current transformer of the present invention.

FIG. 4 is an enlarged sectional view of a main part in an axial direction of a gas insulated equipment tank showing another example of the optical current transformer of the present invention.

FIG. 5 is a sectional view of a gas-insulated equipment tank showing another example of the optical current transformer of the present invention.

FIG. 6 is an enlarged cross-sectional view of a main part in the axial direction of a gas insulated equipment tank showing another example of the optical current transformer of the present invention.

FIG. 7 is a sectional view taken along the line VII-VII in FIG. 6;

FIG. 8 is a sectional view of a gas-insulated equipment tank showing another example of the optical current transformer of the present invention.

FIG. 9 is an example of the configuration of a gas-insulated equipment tank using a conventional optical current transformer.

[Explanation of symbols]

1 gas insulation equipment tank (tank), 3a, 3b, 3c
Current-carrying conductor, 9a light-emitting part, 10a, 10b light-receiving part (measurement part), 11a signal processing circuit (measurement part), 14
a, 14b, 14c, 14d Optical fiber, 20 three-phase insulating spacer (insulating support member), 20a, 22a through hole, 1a cylinder, 21 support member, 23a groove, 24, 2
4a Buffer material, 25 metal plate (partition), 26 metal tube (conductive cylinder).

Claims (8)

[Claims] 1. A cylindrical tank filled with an insulating gas, and three current-carrying conductors in the tank which are supported insulated from the tank and through which a three-phase current extending in the axial direction of the tank flows. An optical current transformer for measuring a current flowing through the current-carrying conductor of a gas-insulated device, comprising: a ring wound around each of the three current-carrying conductors inside the tank; Three optical fibers to be led out, a light emitting unit connected to one end of each of the optical fibers, and for inputting linearly polarized light to the optical fibers, and a light emitting unit connected to the other end of each of the optical fibers, and emitted from the optical fibers And a measuring section for detecting the emitted light to be transmitted and measuring the current flowing through the current-carrying conductor based on the polarization state accompanying the Faraday effect of the light passing through the optical fiber. . 2. The three current-carrying conductors are arranged at regular intervals in a plane perpendicular to the axis of the tank, and each of the three optical fibers has a winding start, a winding end,
2. The optical current transformer according to claim 1, wherein a direction in which both ends are led out is disposed in a direction perpendicular to an axis of the tank and opposite to a center of the three current-carrying conductors. 3. 3. A cylindrical tank filled with an insulating gas, and three current-carrying conductors in the tank, which are insulated from and supported by the tank, and through which a three-phase current extending in the axial direction of the tank flows. An optical current transformer for measuring a current flowing through the current-carrying conductor of a gas-insulated device, comprising: A fiber, a light-emitting portion connected to one end of the optical fiber, for inputting linearly polarized light to the optical fiber, and a light-emitting portion connected to the other end of the optical fiber, for detecting light emitted from the optical fiber, An optical current transformer comprising: a measuring unit that measures a current flowing through the current-carrying conductor based on a polarization state of the light passing through the fiber due to the Faraday effect. 4. The tank is configured by connecting a plurality of cylindrical bodies having flanges at both ends by connecting the flanges to each other, and is supported by being sandwiched between the two connected flanges;
It has a plate-shaped insulating support member having a through-hole formed therein, the current-carrying conductor is supported by the insulating support member through the through-hole, and the optical fiber is embedded and disposed in the insulating support member. The optical current transformer according to claim 1, wherein: 5. The tank is configured by connecting a plurality of cylindrical bodies having flanges at both ends by connecting the flanges to each other, and is supported by being sandwiched between the two connected flanges.
The current-carrying conductor has a plate-shaped support member formed with a through-hole having a diameter larger than that of the current-carrying conductor. The current-carrying conductor penetrates the through-hole so as not to contact the support member. The optical current transformer according to any one of claims 1 to 3, wherein the optical current transformer is wound around the main surface along a groove formed in an annular shape around the through hole. 6. The optical current transformer according to claim 1, wherein a buffer is provided around the optical fiber. 7. A partition, which is electrically connected to the tank and separates an optical fiber wound around the current-carrying conductor from other current-carrying conductors, is provided in the tank. 7. The optical current transformer according to any one of 1 to 2 or 4 to 6. 8. The optical fiber according to claim 1, wherein the optical fiber led out of the tank is disposed so as to penetrate a conductive cylinder connected to an optical fiber lead-out part of the tank. 8. The optical current transformer according to any one of 7.