JP2016156709A - Porcelain-clad optical current transformer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a porcelain-clad optical current transformer whose structure is simple and which is inexpensive and has high reliability.SOLUTION: A porcelain-clad optical current transformer of an embodiment comprises a first container, a second container, a cylindrical insulation tube, an optical current sensor, an optical fiber, and a ventilation unit. A high voltage is applied to the first container. The second container is made a ground potential. The cylindrical insulation tube is joined at one end to the first container and jointed at other end to the second container in order to support the first container and the second container while insulating therebetween. The optical current sensor, accommodated in the first container, measures a current flowing in a metal conductor of a high-voltage part using a Faraday effect. The optical fiber transmits the optical signal of a current detected by the optical current sensor from the first container to the second container through the insulation tube. A ventilation unit is provided in the first container and/or the second container, and has dustproof and waterproof functions.SELECTED DRAWING: Figure 1

Description

  Embodiments described herein relate generally to an insulator type optical current transformer.

  As a device for passing a high-voltage conductor through the soot pipe, for example, there is a gas insulation bushing. In this gas insulation bushing, in order to insulate a high voltage generated in the conductor, a high-pressure insulating gas, for example, 0 It is filled with about 6 MPaG sulfur hexafluoride gas (SF6 gas).

  As a device for measuring the current flowing through a high-voltage conductor in the insulator, there is an insulator type optical current transformer (hereinafter referred to as “optical CT”) through which an optical fiber is passed through the central portion of the insulator. Then, since a high voltage conductor is not passed through the soot pipe, insulation by filling with an insulating gas such as SF6 gas is not required between the high voltage part and the ground potential part inside the soot pipe. Can be insulated.

  However, no matter how much insulation is possible in the atmosphere, if the o-ring seal structure is omitted, dust and sea salt particles contained in the atmosphere will enter the duct along with the air and adhere to the surface of the duct. May cause dielectric breakdown.

  For example, the diameter of the sea salt particles is 0.1 μm to 10 μm in diameter, and since the number of peaks is 4 μm to 5 μm, it is possible for the sea salt particles to enter the inside of the canal even if there is a slight gap. .

  For this reason, the entire dredging pipe is made airtight, so that dust and sea salt particles do not enter the dredging pipe from the atmosphere side, or silicone rubber is filled inside the dredging pipe to prevent dust or sea salt particles from entering from the atmosphere side. It is common to have no structure.

JP-A-1-253523 JP-A-6-162845

  In the optical CT employing the structure as described in the above prior art document, it is necessary to enclose a sealing material such as silicone rubber inside the soot tube, which makes the production complicated. Further, even when the sealing material is not encapsulated, an airtight structure is required. Therefore, it is necessary to make all the connection portions airtight, and there is a problem that the cost of the apparatus becomes expensive.

  The problem to be solved by the present invention is to provide an insulator type optical current transformer having a simple structure, low cost and high reliability.

  The insulator type optical current transformer of the embodiment includes a first container, a second container, a cylindrical insulating tube, a photocurrent sensor, an optical fiber, and a ventilation unit. A high voltage is applied to the first container. The second container is at ground potential. The cylindrical insulating tube has one end coupled to the first container and the other end coupled to the second container, and supports the first container while insulating the first container and the second container. The photocurrent sensor is accommodated in the first container, and measures the current flowing through the metal conductor of the high voltage portion using the Faraday effect. The optical fiber transmits the optical signal of the current detected by the photocurrent sensor from the first container to the second container through the insulating tube. The ventilation unit is provided in the first container and / or the second container, and has a dustproof and waterproof function.

It is side part sectional drawing of the self-supporting pillar type insulator type optical current transformer of one embodiment. It is detail drawing of the ventilation part C (AA cross section) of FIG. It is detail drawing of the ventilation part B of FIG.

Hereinafter, embodiments will be described in detail with reference to the drawings.
(Embodiment)
FIG. 1 is a side sectional view of a self-standing column-type insulator optical current transformer according to one embodiment, FIG. 2 is a detailed view of a ground side ventilation section (AA section) in FIG. 1, and FIG. 1 is a detailed view of a ventilation portion B on the high voltage side of FIG.

  As shown in FIG. 1, the insulator type optical current transformer of one embodiment includes a metal container 2 as a first container provided in a high voltage section, and a metal provided so as to penetrate the inside of the metal container 2. A conductor 1 as a conductor, a photocurrent sensor 3 housed in a metal container 2, a soot tube 4 as a cylindrical insulating tube, a metal container 5 as a second container provided in the ground potential portion, and a metal container 2 The ventilation part B provided in the metal container 5 is provided.

  Ventilation units B and C ventilate the inside and outside of each container (air circulation). Dust-proof function to prevent the entry of fine dust and dust contained in the air and waterproof function to prevent the entry of water droplets such as rainwater. And have. In this example, the ventilation parts B and C are provided in both the high voltage part and the ground potential part, but may be provided only in either one.

  A conductor 1 is passed through the metal container 2 on the high voltage portion side in the horizontal direction, and a photocurrent sensor 3 is accommodated inside the metal container 2. A high voltage (high voltage) is applied to the conductor 1, and a large current flows.

  The metal container 5 is at ground potential. The soot tube 4 has one end coupled to the metal container 2 on the high voltage portion side and the other end coupled to the metal container 5 on the ground potential portion side. The soot tube 4 supports the metal container 2 while insulating the metal container 2 on the high voltage part side and the metal container 5 on the ground potential part side.

  The photocurrent sensor 3 is provided in an annular shape without contact with the conductor 1. The photocurrent sensor 3 measures the current flowing through the conductor 1 using the Faraday effect, and outputs an optical signal corresponding to the measured current value. One or a plurality of photocurrent sensors 3 are provided in the container.

  The optical fiber 6 is a thin fibrous material formed of quartz glass or plastic, and has a two-layer structure of an optical fiber core wire 6a that is a core at the center and a cladding that covers the periphery thereof. The optical fiber 6 transmits the optical signal of the current detected by the photocurrent sensor 3 from the metal container 2 to the metal container 5 through the inside of the tub tube 4.

  The optical fiber 6 is connected to the photocurrent sensor 3 disposed on the high voltage portion side. The optical fiber 6 is wired so as to pass through the vertical tube 4 and enter the metal container 5 disposed on the ground potential portion side.

  As shown in FIG. 2, a metal container 5 for erecting the tub tube 4 is fixed to the ground or the base at the ground potential portion. A junction box 7 is attached to the outside of the side portion of the metal container 5 with screws or the like.

  The connection box 7 is a casing for connecting (connecting) the optical fiber core wires 6a of the optical fiber 6 and processing the extra length of the optical fiber core wire 6a. The face is blocked.

  An opening 8 is provided as a ventilation opening on the side surface of the metal container 5 to which the connection box 7 is attached. The opening 8 is also used as a lead-out portion for pulling out the optical fiber core wire 6a of the optical fiber 6 to the outside.

  A storage portion 9 for connecting the optical fiber core wire 6a and storing the extra length portion is provided outside the opening portion 8. One side (the side opposite to the opening 8) of the storage part 9 is opened, and a filter 10 is attached to the opening. The filter 10 closes the opening of the housing 9 so that the extra length of the internal optical fiber core wire 6a is not scattered.

  The filter 10 has a two-layer structure of a non-woven electret filter 10a as a first filter that removes dust and sea salt particles on the atmosphere side (outside) and a sheet-like filter 10b having water repellency as a second filter on the inside. Has been.

  In this example, the nonwoven fabric electret filter 10a is used as the first filter, but other filters may be used as long as the filter uses a nonwoven fabric and has a hole diameter of 2 μm or less. The sheet filter 10b is, for example, a PTFE filter.

  That is, the ventilation part B is provided with the opening part 8 provided in the side surface of the metal container 5, and the filter 10 with the hole diameter provided in this opening part 8 of 2 micrometers or less.

  As shown in FIG. 3, the ventilation part B installed in the high voltage part has an L-shaped pipe 11 and a filter 10. The metal container 2 is provided with an opening 12 that is a ventilation opening that opens to the side. An L-shaped pipe 11 is provided so as to cover the opening 12.

  That is, one end of the L-shaped pipe 11 is coupled to the opening 12 provided on the side surface of the metal container 2, and the opening 11a at the other end opens in the vertical direction (downward).

  The filter 10 is provided inside the opening 11a so as to close the opening 11a at the end of the L-shaped pipe 11 that opens in the vertical direction. This filter 10 has the same material and function as those provided in the metal container 5 on the ground potential portion side.

Next, the operation of the insulator type optical current transformer of this embodiment will be described.
On the grounding side, since the opening 8 is provided in the metal container 5, it is not necessary to take airtightness as a whole of the insulator type optical current transformer. In addition, it is not necessary to employ an expensive seal structure using an O-ring in a connection portion that requires air-tightness by an existing O-ring.

  The air containing sea salt particles that enter the inside of the tub tube 4 through the opening 8 due to the pressure change always passes through the filter 10. By using, for example, the filter 10 having a hole diameter of 2 μm or less as the filter 10, 70% or more of the sea salt particles can be removed.

  Further, by using a non-woven electret filter 10a for this filter 10, electrostatic coulomb force works and it is possible to capture sea salt particles of 1 μm or less.

  Further, the trapped sea salt particles may melt due to deliquescence, but the water containing the sea salt particles does not spread in the form of a film by a filter sheet 10b having water repellency inside, for example, a filter sheet using PTFE. It does not enter the inside of the tub tube 4.

  Further, by sharing the hole for drawing out the optical fiber 6 with the opening 8, it is not necessary to unnecessarily make a hole dedicated to the drawing in the metal container 5. Further, since the optical fiber 6 is housed in the junction box 7, it is not directly exposed to wind and rain or ultraviolet rays, so that the life can be extended.

  In addition, by providing the opening 12 on the high voltage side, ventilation can be performed by the opening 8 on the ground side and the opening 12 on the high voltage side, but heat is generated by energization on the high voltage side, so the temperature is low. Air flows into the soot tube 4 from the opening 8 on the ground side, and an air flow is generated from the high voltage side opening 12 having a high temperature to the atmosphere. By ventilating the air in which such a flow is generated from the opening 12, the high voltage part can be efficiently cooled.

  Therefore, it is possible to further reduce the size of the photocurrent sensor 3 and the container 2 in the high voltage portion.

  Further, since the inside of the soot tube 4 is ventilated by the opening 8 on the ground side and the opening 12 on the high-pressure side, moisture can be prevented from staying inside the soot tube 4 and condensation can be prevented. The dielectric breakdown does not occur on the creepage surface, and the reliability can be improved. In addition, by using the L-shaped pipe 11 with the opening portion 11a facing the ground side, the rainwater does not collect and is not exposed to ultraviolet rays, so that the life of the tub tube 4 can be extended.

  As described above, according to the insulator type optical current transformer of this embodiment, the metal container 2 and the metal container 5 are provided with the ventilation parts B and C having a dustproof and waterproof function, so that all the connection parts are O-ringed. This eliminates the need to employ a seal structure that uses, eliminates the need for work on the O-ring groove, which is costly, and reduces manufacturing costs.

  In each ventilation part B and C, after removing dust and sea salt particles by using a nonwoven fabric electret filter in the openings 8 and 12, the inside of the tub tube 4 is kept clean, thereby keeping the inside of the tub tube 4 clean. be able to.

  When the insulator type optical current transformer is installed in the vicinity of the sea, for example, the dehydrated sea salt particles are put into the tub tube 4 of the dehydrated sea salt particles by the water-repellent filter sheet of the two-layer filter 10 provided in the ventilation parts B and C. As described above, it is possible to provide a highly reliable insulator type optical current transformer that keeps the inside of the insulator tube 4 clean and does not cause dielectric breakdown.

  Further, since the core wire portion of the optical fiber 6 is processed by extra length processing and stored in the connection box 7 provided on the ground potential portion side, the optical fiber 6 is not exposed to wind and rain and is not exposed to ultraviolet rays. The lifetime of the fiber 6 can be extended.

  Further, the ventilation part B is also provided in the high voltage part opposite to the ground potential part, and the opening part 11a is provided downward, whereby an air flow is generated. The cooling effect by the air flow causes the light of the high voltage part. By reducing the size of the current sensor 3 and the metal container 2, it is possible to use inexpensive members and reduce the total cost of this device. Moreover, since the dew condensation in the tub tube 4 can be prevented by ventilating from the upper and lower ventilation parts B and C, the reliability can be enhanced.

  Moreover, the ventilation part B which has the L-type piping 11 is provided in the metal container 2 by the side of a high voltage part, and the opening part 11a of the L-type piping 11 is orient | assigned to the direction (downward) of the ground, and the inside of the metal container 2 from the ventilation part B Rainwater does not enter or accumulate in the water and is not exposed to ultraviolet rays, thus extending the life of the device.

  Although the embodiment of the present invention has been described, this embodiment is presented as an example and is not intended to limit the scope of the invention. The novel embodiment can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 1 ... Conductor, 2 ... Metal container (high voltage part side), 3 ... Photocurrent sensor, 4 ... Barrel pipe, 5 ... Metal container (grounding potential part side), 6 ... Optical fiber, 6a ... Optical fiber core wire, 7 ... Connection Box, 8 ... Opening (ground potential part side), 9 ... Storage part, 10 ... Filter, 10a ... Non-woven electret filter, 10b ... Water-repellent sheet filter, 11 ... L-type pipe, 11a ... L-type pipe Opening part, 12... Opening part (high voltage part side).

Claims (8)

A first container through which a conductor to which a high voltage is applied is passed;
A second container having a ground potential;
A cylindrical insulating tube having one end coupled to the first container and the other end coupled to the second container, and supporting the first container while insulating the first container and the second container;
A photocurrent sensor that is housed in the first container and measures a current flowing through the metal conductor of the high-voltage portion using a Faraday effect;
An optical fiber that transmits an optical signal of a current detected by the photocurrent sensor from the first container to the second container through the insulating tube;
An insulator-type optical current transformer provided in the first container and / or the second container and having a ventilation part having a dustproof and waterproof function. The ventilation section is
A ventilation opening provided on a side surface of the first container and / or the second container;
The insulator type optical current transformer according to claim 1, further comprising a filter having a hole diameter of 2 μm or less provided in the ventilation port.   The insulator type optical current transformer according to claim 2, wherein the filter uses a nonwoven fabric.   The insulator type optical current transformer according to claim 2, wherein the filter is a non-woven electret filter. The filter is
A first filter for removing dust and sea salt particles;
The insulator type optical current transformer according to claim 2, further comprising a sheet-like second filter having water repellency. The ventilation section is
An L-shaped pipe having one end coupled to a ventilation port provided on a side surface of the first container and the other end opened in a vertical direction;
The insulator-type optical current transformer according to claim 1, further comprising a filter provided so as to close the other end of the L-shaped pipe opened in the vertical direction.   The insulator type optical current transformer according to claim 1, wherein the ventilation unit includes a drawing unit for drawing the optical fiber to the outside.   The insulator-type optical current transformer according to claim 1, further comprising a storage unit that is provided in a ventilation port provided on a side surface of the second container and stores a surplus portion of the optical fiber.

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