JPS5897662A - Electric device - Google Patents

Abstract

PURPOSE:To eliminate an influence of adjacent different-phase magnetic fields and to reduce the size of a device, by forming part of a conductor spirally and installing a magnetic sensor in it in such a way that the sensor faces in a prescribed direction. CONSTITUTION:In a tubular airtight metallic container 1 charged with inulating gas, a pipelike conductor 2 provided with a spiral detection part 2a having prescribed pitch is contained. In the detection part 2a, a Farady effect element 3 where a polarizer and an analyzer are attached is installed facing in a direction determined by the shape and arrangement of the spiral conductor, thereby detecting a magnetic field produced by a current flowing through the direction part 2a in a conductor axis direction. Then, light is inputted from a light source 4 to the Faraday element 3 through optical cables 5 and 6 and the light output after being passed through the Faraday element 3 is guided through optical cables 5 and 6 to a photoelectric converting amplifier 7 to obtain an electric output. A supporting member 8 of epoxy, etc., is provided between two airtight metallic containers 1 to hold the conductor 2.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrical device for measuring the conductor current of an electrical device in which a plurality of current conductors are placed adjacent to each other in a closed container.

Conventionally, as a device for measuring conductor current using a magnetic sensor, a device has been considered in which a magnetic sensor is placed inside a coil to detect an axial magnetic field created by the current flowing through the coil. When this is applied to electrical equipment in which multiple conductors are placed adjacent to each other, at the position of the magnetic sensor within each conductor, not only the magnetic field due to the current of each conductor itself, but also the magnetic field generated by the current of each conductor itself,
There is a magnetic field due to current in other conductors. Since each magnetic sensor detects them simultaneously, the output of the magnetic sensor contains a fairly large proportion of current components of other conductors in addition to the current components of the corresponding conductor being measured, which makes it difficult to obtain sufficient measurement accuracy. The disadvantage is that it cannot be used.

In the present invention, when two or eight current conductors are installed adjacent to each other, a part of the conductors is configured in a spiral shape, and a magnetic sensor is placed inside the conductor by the shape and arrangement of the spiral conductors. By installing it in a predetermined direction,
To provide an electric device that improves measurement accuracy by eliminating the loop of adjacent magnetic fields of other phases, securely fixes a helical conductor by integrally molding a magnetic sensor with a support member, and can be miniaturized.

FIG. 1 shows an embodiment of the present invention. (1) is a tubular closed metal granite container, the inside of which is filled with insulating gas. (
2) is a pipe-shaped conductor housed in a container (1), and is provided with spiral detection portions (2a) at a predetermined pitch.

(3) is a Faraday effect element disposed within the detection section (2a) and equipped with a polarizer/analyzer, which detects the magnetic field in the conductor axis direction created by the current flowing through the detection section (2a). Light is input to the Faraday element (3) from a light source (4) such as an LED through an optical cable (5) (6), and the optical output after passing through the Faraday element (3) is input to the optical cable (5) (6).
) to the photoelectric conversion/amplifier (7), and the electrical output is output. (8) is a support member made of epoxy or the like that is located between the two sealed metal containers (1) and holds the conductor (2), and the detection part (2a) is provided inside it and is integrally molded. .

An optical cable for inputting and outputting light to and from the Faraday element (3) is embedded in a support insulator and led out of the container (1) through the support insulator. The detection part (2a) where the Faraday element (3) is placed becomes high temperature due to heat generation.
In the optical cable (5) near the Faraday element (3),
Uses highly heat-resistant optical fibers such as Teflon jackets. On the other hand, the optical cable (
For 6), a highly airtight optical fiber such as a nylon jacket is used to maintain airtightness between the jacket and the support member (8). These two are connected at a connection point (9) by a method such as fusion bonding.

In addition, the front and back of the outlet from the support member (8) and the container (
The optical fiber (6) outside 1) is wrapped with a shield such as rubber or vinyl to give it mechanical strength.

With the above configuration, without using an airtight optical connector,
It becomes possible to optically connect a part of the sensor to the outside of the container.

Although only one current conductor is shown in FIG. 1, two or eight conductors having a similar structure are arranged in parallel. The Faraday element portions for each phase are installed at the same position in the axial direction of the conductor.

Next, the principle will be explained in the case of an eight-phase conductor.

It is assumed that the a-phase, b-phase, and C-phase conductors are arranged at the vertices of arbitrary triangles. Here, as shown in FIG. 2, an orthogonal coordinate system is used in which the a-phase sensor position is the origin and the a-phase conductor axes are the two axes.

The sensors for each phase conductor are installed so that they are on the xy plane. At this time, the current Ib flowing through the b phase and C phase,
The influence of the magnetic field produced by Ic on the a-phase sensor can be eliminated by the following method.

In the spiral detection part (2a) in Fig. 1, a current flows along the conductor shape, so the magnetic field generated by the current has only an axial component at the sensor position of the own phase, and only the axial component at the sensor position of the other phase. has an axial component and a circumferential component centered around the conductor through which the current flows.

Specifically, the b-phase current Ib and the C-phase current Ic in FIG.
The magnetic field created at the a-phase sensor position has a zM direction component (Hbz, 1ioz) and a circumferential direction component (nb, Hc) centered on each phase conductor, and the circumferential direction component is composed of If divided into minutes, the b-phase and C-phase components of the magnetic field created at the a-phase sensor position are (1), (2
) is expressed by the formula.

Kono-style Niokel Hb, Ha, Hbz, Hc
Z is a storm determined by the structure of the spiral detection part (2a) and the distance between busbars in addition to the X flow of each phase.

On the other hand, let the direction of sensitivity of the a-phase sensor be the direction of the unit vector shown in FIG. At this time, the sensitivity becomes zero in the perpendicular direction. If the angle between the two axes of the projection onto the -X plane is α, and the angle between the two axes and the two axes of the projection onto the zy plane is β, then the vector X.

The y and z components are = (sin α cos β, aosa sin β, c
osαaosβ”)・(1)

The magnetic field of other phases (b, 0 phase) detected by the a-phase sensor is...(4).In order to make this zero, since are independent of each other...(5) must be satisfied. Bye. Above (1), (2) I (3
), From equation (5), oosζbsinζa −81n
ζbeollζCeO3ζbsinζe-111nζb
cosζC is obtained. In equations (6) and (7), Hb
z /Hb and Hcz/He are quantities that are not related to the magnitude of each phase current.

Therefore, the −a phase sensor is expressed as α in equations (6) and (7).
, β, it is possible to completely eliminate the effects of the b-phase current and the C-phase current.

Further, in the present invention, since the Faraday element is integrally molded in the support member, mechanical displacement of the Faraday element can be prevented and miniaturization can be achieved.

Furthermore, by using highly heat-resistant optical fibers such as Teflon and jackets for the optical cable near the Faraday element, it is possible to maintain sufficient characteristics even under high temperatures caused by the heat generated by the current conductor, and - force support is possible. By using a high-strength optical fiber such as nylon or jacket for the optical cable that leads out from the insulator, and maintaining airtightness between the jacket and the supporting insulator (8), there is no need for an airtight optical connector. There is an advantage that

In carrying out the present invention, by embedding a shielding member made of a ferromagnetic material in the supporting insulator near the spiral conductor, the magnetic field of the own phase can be strengthened and the magnetic field leaking to other phases can be reduced. , the permissible range of sensor installation angle settings is widened, and measurement accuracy is improved.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention, and FIGS. 2 and 8 are explanatory diagrams showing the operation of the present invention. In the figure, (1) is a container, (2) ζ is a conductor, (3H is a magnetic sensor (Faraday element), +8) is a support member. Agent Makoto Kuzuno - Figure 1 Figure 2 Figure 3 Procedural amendment (voluntary) Commissioner of the Patent Office 2, Name of the invention electrical device 3, Person making the amendment 6, Subject of extraction (the full text of the υ specification) (!) Drawing 6, Contents of amendment (υThe entire text of the description is corrected as shown in the attached sheet. (2) Figures 2 and 8 are corrected as shown in the attached sheet. 7. List of attached documents (1) Full text amended 1 copy of specification (2) Figure 2, Figure 8 At least 1 copy each of amended specification 1, title of invention electrical device 2, claims (1) 2 or 8 units adjacent to each other in a container A magnetic sensor detects the current in each conductor arranged through which a multiphase current flows, wherein at least a part of each conductor is configured in a spiral shape, and the multiphase magnetic flux generated by the multiphase current is detected by a magnetic sensor. The magnetic sensor having sensitivity in one direction is disposed within the spiral conductor so as to cancel the effects of an axial component and a vertical component perpendicular to the axial component on the magnetic sensor, An electrical device comprising an insulating support member fixed to the container, surrounding the outer periphery of the conductor in which the conductor and the magnetic sensor are integrated. (2) A ferromagnetic member between each conductor in the support member. Alternatively, the electrical equipment according to claim 1, characterized in that a conductive member is embedded. (3) Claim 1, characterized in that the magnetic sensor is a magneto-optical element. or the electrical device according to item 2. 3. Detailed Description of the Invention The present invention relates to an electrical device adapted to measure conductor current of an electrical device in which a plurality of current conductors are placed adjacent to each other in a closed container. In order to measure conductor current using a magnetic sensor, a device has been considered that places a magnetic sensor inside a coil and detects the axial magnetic field created by the current flowing through the coil. When applied to electrical equipment in which conductors are placed adjacent to each other, at the position of the magnetic sensor within each conductor, there is not only a magnetic field due to the current of each conductor itself, but also a magnetic field due to the current of other conductors.Each magnetic sensor Since these are detected simultaneously, the output of the magnetic sensor contains a large proportion of the current components of other conductors in addition to the current components of the corresponding conductor being measured, and has the disadvantage that sufficient measurement accuracy cannot be obtained. In the present invention, when two or eight current conductors are installed adjacent to each other, a part of the conductor is configured in a spiral shape, and a magnetic sensor is placed inside the conductor, depending on the shape and arrangement of the spiral conductor. By installing it in a predetermined direction determined by To provide an electrical device that can be made smaller and more compact. FIG. 1 shows an embodiment of the present invention. (11 is a tubular sealed metal container, the inside of which is filled with insulating gas.)
2) is a pipe-shaped conductor housed in a container (1), and is provided with spiral detection portions (2a) at a predetermined pitch. (Third item: A Faraday effect element placed inside the detection part (2a) and attached with a polarizer/analyzer detects the magnetic field in the conductor axis direction created by the current flowing through the detection part (2a).Faraday element (3) In this method, light is inputted from a light source (4) such as an LED through an optical cable (5) (6), and the optical output after passing through a Faraday element (3) is input to an optical cable (5) (6).
) to the charging converter/amplifier (7) and taken out as an electrical output. (8) is a support member made of epoxy or the like that is located between the two sealed metal containers (1) and holds the conductor (2), and the detection part (2a) is provided inside it and is integrally molded. . An optical cable for inputting and outputting light to and from the Faraday element (3) is embedded in a support insulator and led out of the container (1) through the support insulator. The detection part (2a) where the Faraday element (3) is placed becomes high temperature due to heat generation.
In the optical cable (5) near the Faraday element (3),
Uses highly heat-resistant optical fibers such as Teflon jackets. On the other hand, the optical cable (
For 6), a highly airtight optical fiber such as a nylon jacket is used to maintain airtightness between the jacket and the support member (8). These two are connected at a connection point (9) by a method such as fusion bonding. Note that the front and back of the outlet from the support member (8) and the container (
The optical fiber (6) outside 1) is wrapped with a coating of rubber, vinyl, etc. to give it mechanical strength. With the above configuration, without using an airtight optical connector,
It becomes possible to optically connect a part of the sensor to the outside of the container. Although only one current conductor is shown in FIG. 1, two or eight conductors having a similar structure are arranged in parallel. The Faraday element portions for each phase are installed at the same position in the axial direction of the conductor. Next, the principle will be explained in the case of an eight-phase conductor. It is assumed that the C-phase, b-phase, and C-phase conductors are arranged at the vertices of arbitrary triangles. Here, as shown in FIG. 2, an orthogonal coordinate system is used in which the C-phase sensor position is the origin and the C-phase conductor axis is the Z-axis. The sensors for each phase conductor are installed so that they are on the XY plane. At this time, the current Ib flowing through the b phase and C phase,
The influence of the magnetic field created by Ic on the C-phase sensor can be eliminated by the following method. In the spiral detection part (2a) in Fig. 1, a current flows along the conductor shape, so the magnetic field generated by the current has only an axial component at the sensor position of the own phase, and only the axial component at the sensor position of the other phase. has an axial component and a circumferential component centered around the conductor through which the current flows. Specifically, the b-phase current 1b and the C-phase current Ic in FIG.
The magnetic field created at the C-phase sensor position has a Z-axis direction component (Hbz, H(z)) and a circumferential direction component (Hb, Hc) centered on each phase conductor.Furthermore, the circumferential direction component is , the b-phase and C-phase components of the magnetic field created at the C-phase sensor position are (IJ, +2
It is expressed by the following equation. Here, * is a symbol representing a vector. Hb, Hc, Hbz * Hcz in this formula
is a quantity determined by the structure of the spiral detection section (2a) and the distance between the busbars in addition to the current of each phase. On the other hand, the sensitivity direction of the a-phase sensor is assumed to be the direction of the unit vector shown in FIG. In this case, the sensitivity becomes zero in the direction perpendicular to Kiroku. If the angle between the projection onto the z-x plane and the Z-axis is α, and the angle between the projection onto the z-′y plane and the Z-axis is β, then the x, y, and z components of the vectors are n = (5ina cosβ, cosαsfnβ,
C08aCO8β) ■・-(3) Magnetic field Ha of other phases (b, C phase) detected by the C phase sensor
is Ho; Hb-n ten Hc-n ・・・・・・・・・
...River... (41, and in order to make this zero, Hb and Hc are independent of each other, so Hb-n=H(-n=o... Song...・・・
Song... All you have to do is satisfy (5). Above (1),
+21, (3), (from formula 51 cosψbsi
nψ, −5inpbcos9cCoSfb! lln 9
+(-5In(Pbcos(p.) is obtained.(!l) In equation (7), Hbz/Hb
and Hcz/)(,. is a quantity that is not related to the magnitude of each phase current. Therefore, by installing the C phase sensor in the direction determined by α and β in equations (6) and (7), , b-phase current, C
It becomes possible to completely eliminate the influence of phase currents. The above has described the C-phase sensor, but it is also possible to eliminate the effects of other phases on the b-phase and C-phase sensors as well, and the sensors installed in each phase are protected against the magnetic field caused by the current of the own phase. Since it detects only the phase difference, measurement accuracy is improved without being affected by other phases. Hbz/Hb or Hc in equations (6) and (7)
The value of z/) (( is determined by the structure of the spiral conductor and the arrangement of each phase conductor, but its absolute value is sufficiently small compared to l. Therefore, the mounting angles α and β of the sensor are sufficiently small values. , the decrease in sensitivity to the self-phase due to the deviation between the sensor's sensitivity direction and the direction of the magnetic field due to the self-phase current is minute and does not pose a problem.As described above, according to the present invention, the conductor has a spiral structure. By generating an axial magnetic field and setting the number of rotations and pitch to appropriate values, it is possible to supply a magnetic field with a strength that matches the sensitivity of the Faraday element. The sensitivity direction of (6)
, (7) By setting the angle t shifted from the axial direction of the lees, it becomes possible to eliminate the influence of other lees. Further, in the present invention, since the Faraday element is integrally molded in the support member, mechanical displacement of the Faraday element can be prevented and miniaturization can be achieved. Furthermore, by using a highly heat-resistant optical fiber such as a Teflon jacket in the optical cable near the Faraday element, it is possible to maintain sufficient characteristics even under high temperatures caused by the heat generated by the current conductor. By using a highly airtight optical fiber such as a nylon jacket for the optical cable that leads from the inside to the outside, and maintaining airtightness between the jacket and the supporting insulator (8), an airtight optical connector is not required. There are advantages. In carrying out the present invention, by embedding a shielding member made of a ferromagnetic material in the supporting insulator near the spiral conductor, the magnetic field of the own phase can be strengthened and the magnetic field leaking to other phases can be reduced. , the permissible range of sensor installation angle settings is widened, and measurement accuracy is improved. 4. Brief Description of the Drawings FIG. 1 is a block diagram showing one embodiment of the present invention, and FIGS. 2 and 8 are explanatory diagrams showing the operation of the present invention. In the figure, (1) is a container, (2) is a conductor, (3) is a magnetic sensor (Faraday element), and (8) is a support member. Agent Shin Kuzuno - Figure 2 Mazu Figure 3

Claims (3)

[Claims] (1) In a device in which two or eight conductors are arranged adjacent to each other in a container and the current in each conductor through which a multiphase current flows is detected by a magnetic sensor, at least a part of each conductor is configured in a spiral shape. The helical conductor is designed to cancel the influence of the axial component of the conductor and the vertical component perpendicular to the axial component of the multiphase magnetic flux generated by the multiphase current on the magnetic sensor. The above-mentioned magnetic sensor having sensitivity in one direction is disposed, and an insulating support member that surrounds the outer periphery of the above-mentioned conductor on which the above-mentioned magnetic sensor is disposed and integrates the above-mentioned conductor and the above-mentioned magnetic sensor is fixed to the above-mentioned container. Device. (2) The electrical device according to claim 1, wherein a ferromagnetic member or a conductive member is embedded between each conductor in the support member. (3) The electric device according to claim 1 or 2, wherein the magnetic sensor is a magneto-optical element.