JP2000121675A - Light converter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To fit or remove a measured conductor during energization by dividing a winding frame into two winding frame sections in the peripheral direction, connecting one-end sections in the peripheral direction with a hinge, and forming an opening section at the other ends. SOLUTION: A winding frame 3 is divided into two winding frame sections 3A, 3B, and one-end faces 3C of both winding frame sections 3A, 3B are formed into the linear shape and connected together via a hinge 11. The other split faces 3D of the winding frame sections 3A, 3B are formed into a Z-shape to be butted together, and the split faces 3D are opened in the peripheral direction by the hinge 11 to form an opening section 12 so that a measured conductor 1 can be inserted into it. The measured conductor 1 being energized can be fitted or removed to or from the winding frame 3, and a flowing current I can be measured. The measured conductor 1 is not required to be interrupted for current measurement, a light current transformer can be moved in a hot line, and the work efficiency of current measurement is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical current transformer for measuring a current flowing through a conductor using a Faraday effect type optical fiber having a property that the plane of polarization of transmitted light rotates in proportion to the strength of a magnetic field. In particular, the present invention relates to an optical current transformer that can be detached even while the conductor to be measured is energized.

2. Description of the Related Art By using an optical current transformer using a Faraday effect type optical fiber for current measurement, there is no iron core saturation phenomenon as compared with a conventional current transformer in which a winding is wound around an iron core. It is possible to reduce the size because it is easy to insulate.
In addition, there is an advantage that the electric substation can be totally controlled in the future by the optical current transformer. FIG. 11 is a perspective view showing a configuration of a conventional optical current transformer. A Faraday effect type optical fiber 2 is wound around the outer periphery of a winding frame 3 having no magnetism, and an input optical fiber 7 is connected to an input end 2A of the Faraday effect type optical fiber 2 via a polarizer 4 to form a Faraday effect. An output optical fiber 8 is connected to an output end 2B of the mold optical fiber 2 via an analyzer 5 and a lens 6. The conductor to be measured 1 through which the current is measured penetrates the inside of the bobbin 3. FIG.
In 1, the Faraday effect type optical fiber 2 has a property that the polarization plane of light passing therethrough rotates in proportion to the strength of the magnetic field, and is made of, for example, lead glass (quartz glass containing a large amount of lead oxide). Optical fiber. The Faraday effect is a phenomenon in which, when light passes through lead glass or the like placed in a magnetic field, the polarization plane of the light rotates by a rotation angle θ = V · H · L. Here, V is the Verdet constant, H is the magnetic field in the light traveling direction, and L is the path length of the light. Lead glass is
The Verde constant V is about six times as large as that of general quartz glass containing no lead oxide, and the rotation angle θ of the polarization plane of light with respect to the magnetic field H is large. However, the input optical fiber 7 and the output optical fiber 8 are ordinary silica glass optical fibers containing no lead oxide or plastics optical fibers. When the current I flows through the conductor 1 to be measured, a magnetic field H that increases and decreases in proportion to the current I is formed around the conductor I. In this state, when the incident light P1 is injected into the input optical fiber 7, the incident light P1 is converted into linearly polarized light P in one direction by the polarizer 4, and the Faraday effect type optical fiber 2
Input terminal 2A. When the light P passes through the Faraday effect type optical fiber 2, its polarization plane is rotated by the rotation angle θ due to the magnetic field H. The light P inclined by the rotation angle θ reaches the output end 2B of the Faraday effect type optical fiber 2 and is injected into the analyzer 5. The analyzer 5 transmits only light components in the direction that can pass through the light P, is condensed by the lens 6, and is emitted to the output optical fiber 8 as transmitted light P <b> 2. Transmitted light P when no current is flowing through conductor under test 1
The amount of change in the amount of the transmitted light P2 when the current flows through the conductor under measurement 1 is proportional to the rotation angle θ with respect to the amount of the light 2, so that the amount of change in the amount of the transmitted light P2 is calculated by You can know. The change in the amount of the transmitted light P2 is converted into an electric signal by a converter (not shown) and output.

However, the conventional apparatus as described above has a problem that the optical current transformer cannot be mounted while the conductor to be measured is energized. In other words, it is necessary to penetrate the conductor to be measured through the bobbin, temporarily stop energization of the conductor to be measured, remove one end of the conductor to be measured from the mating conductor once, and place the conductor to be measured into the bobbin. Had to be penetrated. In order to do so, a power outage must be performed, so that current measurement has conventionally been very difficult. An object of the present invention is to provide an optical current transformer that can be detached even while the conductor to be measured is energized.

According to the present invention, there is provided, in accordance with the present invention, a Faraday effect type optical fiber having a property that a plane of polarization of light passing therethrough rotates in proportion to the strength of a magnetic field. The conductor to be measured circulates around the outer periphery of the winding frame, and transmits light from the input end to the output end of the Faraday effect type optical fiber, and is proportional to the rotation angle of the polarization plane of the light passing through the Faraday effect type optical fiber. In an optical current transformer for outputting a signal and measuring a current flowing through the conductor to be measured from the signal, the winding frame includes a winding frame portion divided into two in a circumferential direction, and the measured conductor is It is preferable that the opening into which the is inserted can be formed. This allows the conductor to be measured to be inserted from the opening while the conductor to be measured is energized, and the current to be measured in the conductor to be measured can be measured. In such a configuration, one ends of the winding frame portion in the circumferential direction may be connected to each other via a hinge, and the opening may be formed at the other circumferential end of the winding frame portion.
Further, in such a configuration, one ends of the bobbin portions may be connected via pins embedded in both the bobbin portions, and the opening may be formed at the other end of the bobbin portion. . Further, in such a configuration, the ends of the bobbin portion may be screwed to each other, and one of the bobbin portions may be removed by removing the screw to form the opening.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments. FIG. 1 is a perspective view illustrating a configuration of an optical current transformer according to an embodiment of the present invention. The winding frame 3 comprises winding frame portions 3A and 3B divided into two in the circumferential direction. Reel 3A, 3
B, one of the divided surfaces 3C is linear and the hinge 11
Are connected to each other. The other divided surface 3D of the winding frame portions 3A and 3B is Z-shaped and abuts each other. The other parts are the same as those of the conventional configuration shown in FIG. FIG. 2 is a perspective view showing a configuration in which an opening 12 is formed in the winding frame 3 of FIG. With the hinge 11, the bobbin 3
A divided surface 3D of A and 3B is opened in the circumferential direction, and an opening 12 is formed. The conductor to be measured 1 can be inserted through the opening 12. Therefore, the current I flowing through the conductor to be measured 1 can be measured even while the conductor to be measured 1 is energized. This eliminates the need for a power outage when measuring the current of the conductor to be measured, and allows the optical current transformer to be moved into the live line, greatly improving the efficiency of current measurement. FIG. 3 is a perspective view showing a configuration of an optical current transformer according to another embodiment of the present invention. The winding frame 3 is a winding frame portion 3A, 3
B, one of the divided surfaces 3C of the winding frame portions 3A and 3B is Z-shaped, and the surfaces divided in parallel in the circumferential direction are connected to each other via the hinge 11. Others are the same as FIG. FIG. 4 is a perspective view showing a configuration in which an opening 12 is formed in the winding frame 3 of FIG. The hinge 11 opens the dividing surface 3D of the winding frame portions 3A and 3B in the axial direction, and opens the opening 1
2 are formed. The conductor 1 to be measured is
Can be inserted. Therefore, the current I flowing through the conductor to be measured 1 can be measured even while the conductor to be measured 1 is energized. FIG. 5 is a perspective view showing a configuration of an optical current transformer according to still another embodiment of the present invention. Reel 3
Is divided into reel portions 3A and 3B, and one of the divided surfaces 3C of the reel portions 3A and 3B is linear and connected via pins 13 embedded in both the divided surfaces 3C in the circumferential direction. Have been. Others are the same as FIG. FIG.
FIG. 6 is a perspective view illustrating a configuration in which an opening 12 is formed in the winding frame 3 of FIG. 5. With the pin 13 as a fulcrum, the dividing surface 3D of the winding frame portions 3A and 3B is opened in the axial direction to form the opening 12. The conductor to be measured 1 can be inserted through the opening 12. Therefore, the current I flowing through the conductor to be measured 1 can be measured even while the conductor to be measured 1 is energized. FIG. 7 is a perspective view showing a configuration of an optical current transformer according to still another embodiment of the present invention. The reel 3 is the reel 3
A, 3B, and one of the divided surfaces 3C of the winding frame portions 3A, 3B has a Z-shape, and the pins 13 embedded in the axial direction are embedded in both of the surfaces divided in parallel in the circumferential direction. Are connected via Others are the same as FIG. FIG. 8 is a perspective view showing a configuration in which an opening 12 is formed in the winding frame 3 of FIG. With the pin 13 as a fulcrum, the winding frame 3A,
An opening 12 is formed by opening the dividing surface 3D of 3B in the circumferential direction. The conductor to be measured 1 can be inserted through the opening 12. Therefore, the current I flowing through the conductor to be measured 1 can be measured even while the conductor to be measured 1 is energized. FIG. 9 is a perspective view showing a configuration of an optical current transformer according to still another embodiment of the present invention. The reel 3 is the reel 3
A, 3B, and the divided surfaces 3E of the winding frame portions 3A, 3B are cutout surfaces that fit together, and the divided surfaces 3E are fixed to each other with screws 14. Others are shown in Figure 1
Is the same as FIG. 10 is a perspective view showing a configuration in which the opening 12 is formed in the winding frame 3 of FIG. The screw 14 is removed, and the winding frame portions 3A and 3B with the screw holes 15 are formed.
An opening 12 is formed which is separated from the opening and opened in the circumferential direction. The conductor to be measured 1 can be inserted through the opening 12. Therefore, the current I flowing through the conductor to be measured 1 can be measured even while the conductor to be measured 1 is energized. In addition, as a method of providing an opening in the winding frame, various other configurations can be considered. For example, in FIG. 1, the hinge 11 may be replaced by a plate, and the divided surfaces 3C of the winding frames 3A and 3B may be fixed by screws. By removing the screws, the winding frames 3A and 3B can be divided so that the opening 12 can be formed. Alternatively,
Hooks in which the winding frame portions 3A and 3B fit each other may be attached to the division surface 3C. By removing the hooks, the winding frames 3A and 3B can be divided so that the opening 12 can be formed.

According to the present invention, as described above, the winding frame is formed of a winding frame portion divided into two in the circumferential direction, and the opening for inserting the conductor to be measured can be formed in the winding frame. By doing so, the conductor to be measured is inserted from the opening even while the conductor to be measured is energized, and current measurement of the conductor to be measured becomes possible. This eliminates the need for a power outage when measuring the current of the conductor to be measured, and also allows the optical current transformer to be moved into the live line, greatly improving the efficiency of current measurement.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a configuration of an optical current transformer according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a configuration in which an opening is formed in the bobbin of FIG. 1;

FIG. 3 is a perspective view showing a configuration of an optical current transformer according to another embodiment of the present invention.

FIG. 4 is a perspective view showing a configuration in which an opening is formed in the bobbin of FIG. 3;

FIG. 5 is a perspective view showing a configuration of an optical current transformer according to still another embodiment of the present invention.

FIG. 6 is a perspective view showing a configuration in which an opening is formed in the bobbin of FIG. 5;

FIG. 7 is a perspective view showing a configuration of an optical current transformer according to still another embodiment of the present invention.

8 is a perspective view showing a configuration in which an opening is formed in the bobbin of FIG. 7;

FIG. 9 is a perspective view showing a configuration of an optical current transformer according to still another embodiment of the present invention.

FIG. 10 is a perspective view showing a configuration in which an opening is formed in the bobbin of FIG. 9;

FIG. 11 is a perspective view showing a configuration of a conventional optical current transformer.

[Explanation of symbols]

1: conductor to be measured, 2: Faraday effect type optical fiber, 2
A: input end, 2B: output end, 3: reel, 3A, 3B: reel, 3C, 3D, 3E: division surface, θ: rotation angle, I:
Current, 7, 8: optical fiber, 11: hinge, 12: opening, 14: screw, 15: screw hole

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Kazunori Yamashita 4-1 Egasaki-cho, Tsurumi-ku, Yokohama-shi, Kanagawa Prefecture Inside the Electric Power Research Laboratory, Tokyo Electric Power Company (72) Inventor Kiyoshi Fujii Tanabe, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture No. 1-1 Nitta Fuji Electric Co., Ltd. (72) Inventor Hidenobu Koide 1-1-1 Tanabe Nitta, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture F-term in Fuji Electric Co., Ltd. 2G025 AA03 AA04 AB09 AB10 AC06

Claims (4)

[Claims] 1. A Faraday effect type optical fiber having a property that a plane of polarization of light passing therethrough rotates in proportion to the strength of a magnetic field is wrapped around the outer circumference of a bobbin through which a conductor to be measured passes. Passes light from the input end of the optical fiber to the output end, outputs a signal proportional to the rotation angle of the plane of polarization of the light passing through the Faraday effect type optical fiber, and measures the current flowing through the conductor to be measured from this signal. Wherein the winding frame comprises a winding frame portion divided into two in the circumferential direction, and an opening through which the conductor to be measured is inserted can be formed in the winding frame. Sink. 2. The optical current transformer according to claim 1, wherein one ends in a circumferential direction of the bobbin portion are connected via a hinge,
An optical current transformer, wherein the opening is formed at the other end in the circumferential direction of the winding frame. 3. The optical current transformer according to claim 1, wherein one ends of the reel portions are connected to each other via pins embedded in both of the reel portions, and the other ends of the reel portions are connected to the other ends of the reel portions. An optical current transformer, wherein an opening is formed. 4. The optical current transformer according to claim 1, wherein the ends of the bobbin portions are screwed to each other, and one of the bobbin portions is removed by removing a screw to form the opening. An optical current transformer, characterized in that: