JPH0222700Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a current measuring device that measures the current of a conductor housed in a container.

This is a conventional current measuring device shown in FIGS. 1 and 2. In the figure, containers 1, 2, and 3 are filled with insulating gas at a predetermined pressure to insulate conductors 4, 5, and 6 to which high voltage is applied. Conductor 4 of other phase,
The magnetic field generated by the current flowing through the containers 1, 2, 3 enters the containers 1, 2, 3 and the magnetic sensors 7, 8, 9
This has the disadvantage that the measurement accuracy of the current flowing through the conductors 4, 5, 6 by the magnetic sensors 7, 8, 9 is reduced.

This invention was made in order to eliminate the above-mentioned drawbacks, and a container is constructed by sequentially connecting first to third cylindrical bodies in series on the same axis.
A conductor is placed through the container, and a magnetic sensor is placed within the second cylinder at a predetermined distance from the conductor.
A current measuring device is provided in which electrical measurement accuracy is improved by configuring the electrical resistance value of the second cylindrical body to be smaller than the electrical resistance values of the first and third cylindrical bodies.

The figures will be explained below. In FIGS. 3 and 4, 1, 2, and 3 are first to third containers arranged approximately parallel to each other, which are cylindrical containers with the same cross-sectional shape and connected in series on the same axis. 1st
cylinders 1a, 2a, 3a and second cylinders 1b, 2
b, 3b and third cylindrical bodies 1c, 2c, 3c. Second cylindrical body 1b, 2b, 3b
are the first cylindrical bodies 1a, 2b, 3b and the third cylindrical body 1
It is constructed so that the electrical resistance is smaller than that of c, 2c, and 3c. For example, the first cylindrical bodies 1a, 2
When a, 3a and the third bodies 1c, 2c, 3c are made of stainless steel or aluminum, the second
The cylindrical bodies 1b, 2b, and 3b are made of copper. 4,
5 and 6 are conductors that penetrated the containers 1, 2, and 3, 7,
8 and 9 are arranged at a predetermined distance from the conductors 4, 5 and 6 in the second bodies 1b, 2b and 3b so as to be operated by the magnetic field in the circumferential direction of the containers 1, 2 and 3. It is a magnetic sensor that consists of a search coil, a Hall element, a magneto-optical sensor, etc. The magnetic sensors 7, 8, 9 are arranged at right angles from the conductors 4, 5, 6 to the plane containing each conductor 4, 5, 6 in order to be less susceptible to the influence of the current flowing through the conductors 4, 5, 6 of other phases. placed in the direction.

The second bodies 1b, 2b, 3b are the first cylindrical body 1
a, 2a, 3a and third cylinder 1c, 2c, 3c
The electrical resistance value is smaller than that of . Due to the magnetic field of other phases applied to the second cylinders 1b, 2b, 3b,
An induced current flows in the second cylindrical bodies 1b, 2b, 3b to cancel the current. Second cylindrical body 1b, 2
Since the electric resistance value of cylindrical bodies 1b and 3b is small, the induced current value is large, penetrating the wall surface and flowing into the second cylindrical bodies 1b and 2.
The other phase magnetic fields leaking into the first cylinders 1a, 2a, 3a and the third cylinders 1c, 2c, 3b
The amount of magnetic field leaking into c is smaller than that of other phases. Therefore, the influence of magnetic fields of other phases by the magnetic sensors 7, 8, and 9 is extremely reduced, and the magnetic sensors 7, 8, and 9
Improves current measurement accuracy.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a conventional current measuring device, Fig. 2 is a sectional view of Fig. 1, Fig. 3 is a perspective view of an embodiment of this invention, and Fig. 4 is a sectional view of Fig. 3. . In the figure, 1, 2, 3 are containers, 1a, 2a, 3a are first
1b, 2b, 3b are the second cylinders, 1c,
2c and 3c are third cylindrical bodies, and 4, 5, and 6 are conductors. Note that the same reference numerals in each figure indicate the same or equivalent parts.

Claims (1)

[Scope of utility model registration request] A container is constructed by sequentially connecting first to third cylindrical bodies in series on the same axis, a plurality of the containers are arranged substantially in parallel, and a conductor is arranged in each container. , a magnetic sensor for measuring the current of the conductor is disposed within the second cylinder at a predetermined distance from the conductor, and the electrical resistance value of the second cylinder is measured between the first and third cylinders. A current measuring device characterized in that the current measuring device is configured so that the electrical resistance value is smaller than the electrical resistance value of the body.