JPS5930506Y2 - Insulator with built-in current transformer - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an insulator with a built-in current transformer, which has been improved to specifically prevent errors caused by the influence of magnetic flux generated by adjacent electric wires.

An insulator with a built-in current transformer, in which the primary wire is insulated and supported on the top of the insulator, and the secondary coil wound around the iron core is inserted into the internal space of the insulator, has a relatively simple structure and can be easily connected to the secondary coil. Since it can induce a secondary voltage, it is widely used to detect short-circuit accidents or different-phase ground faults in power distribution lines.

However, in this type of insulator with a built-in current transformer, the primary wire and the secondary coil are loosely coupled magnetically, so the conventional structure is easily affected by nearby magnetic fields.

Therefore, if there is another electric wire adjacent to this type of insulator with a built-in current transformer, there is a possibility that an error may occur due to the influence of the magnetic flux generated by this electric wire.

In view of the above-mentioned prior art, it is an object of the present invention to provide an insulator with a built-in current transformer that eliminates the influence of surrounding magnetic fields as much as possible and guarantees high measurement accuracy.

Embodiments of the present invention will be described in detail below with reference to the drawings.

As shown in FIG.
is provided, and the primary electric wire 2 is insulated and supported via this insulator groove 1a.

On the other hand, in the internal space 1b of the shaft 1, there is a secondary coil 4 wound around an iron core 3, which is attached to a bottom plate 5 via a support fitting 6.

The secondary coil 4 is magnetically coupled to the primary wire 2 and generates a voltage proportional to the current flowing through the primary wire 2.

The primary electric wire 2 is covered with a wire presser 8.

This electric wire holder 8 has a semicircular shape adapted to the curvature of the primary electric wire 2, and has a central portion 8a that abuts and covers the outer peripheral surface of the primary electric wire 2, and a central portion 8a that extends from the central portion 8a on both sides. The flange portions 8b, 8 which are in contact with the top of the extended paddle 1
C.

Together with the primary electric wire 2, it is tightened at the top of the paddle 1 by a binding wire (not shown).

At this time, as shown in FIG. 2, the nuts 9, 9a are buried in the top of the insulator, and the screws 10, 108 are inserted into the nuts 9, 9a from the upper surface of the flange portions 8b, 8C of the wire holder 8. They may be fixed by screwing together.

Further, the studs 7 are for fixing the insulator with a built-in current transformer to a support arm (not shown), and are planted in the bottom plate 5 facing downward.

In the insulator with a built-in current transformer having such a structure, among the magnetic lines of force caused by the current flowing in the nearby electric wires, the lines of magnetic force near the secondary coil 4 do not pass through the secondary coil 4 due to the influence of the wire retainer 8 having high magnetic permeability. Concentrate on the wire holder 8.

Therefore, the secondary coil 4 is magnetically shielded from such lines of magnetic force.

On the other hand, since there is no magnetic material between the primary wire 2 and the secondary coil 4, the lines of magnetic force caused by the current flowing through the primary wire 2 can be linked to the secondary coil 4.

In this way, according to the present invention, the secondary coil is magnetically shielded from external lines of magnetic force without disturbing the magnetic coupling between the primary wire and the secondary coil.
The voltage value taken out from the next coil is a predetermined and accurate value that is not affected by external magnetic fields.

In other words, higher measurement accuracy is guaranteed compared to conventional technology.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing one embodiment of the present invention, and FIG. 2 is a longitudinal sectional view showing a part of another embodiment in which the manner in which the wire holder is attached to the insulator is different. In the drawing, 1 is a peeler, 1b is an internal space, 2 is a primary electric wire,
3 is an iron core, 4 is a secondary coil, and 8 is a wire holder.

Claims (1)

[Scope of utility model registration request] In an insulator having an insulator in which a primary electric wire is insulated and supported at the top and an internal space is provided, and a secondary coil wound around an iron core is inserted into the internal space, the primary electric wire is held by a wire holder made of a magnetic material. An insulator with a built-in current transformer.