JP2554601Y2 - Resin mold current transformer - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insulation structure for a high voltage coil of a resin molded current transformer.

[0002]

2. Description of the Related Art FIGS. 2 and 3 are sectional views and connection diagrams of a resin mold current transformer, and FIG. 4 is a sectional view of a high-voltage coil. The resin mold current transformer is manufactured by winding an insulator (not shown) on an iron core 9, winding a low-voltage coil 8, incorporating the high-voltage coils 1 and 2, and then molding with a synthetic resin 7. The high voltage coils 1 and 2 are divided, and a connection plate 1
Zeros are connected in series to provide the necessary number of turns for current composition of the current transformer, and both ends are connected to primary terminals 5 and 6 for external connection.

The high-voltage coils 1 and 2 are provided with a shield layer 4 wrapped with semiconductive tapes having a high adhesiveness to the synthetic resin 7 on the outer periphery thereof for alleviating an electric field. The shield layer 4 is always connected to the high voltage coils 1 and 2 at the same potential at one point in order to prevent a floating potential.

By the way, in the case of a current transformer, especially for a large current circuit, the high-voltage coils 1 and 2 are formed by winding and forming strip-shaped bare conductors 1 and 2. In this case, if the shield layer 4 is wound directly on the bare conductor, a small current determined by the semiconductive resistance flows through the shield layer 4 between the turns of the bare conductor, and the transformation ratio of the current transformer becomes unstable. Could be. For this reason, before winding the shield layer 4, a not-shown interval insulator is inserted between the turns, and the bare conductor is wound and covered with the insulator 3.

[0005]

The work of winding the insulator 3 on the high-voltage coils 1 and 2 requires a tape-shaped insulator to be wound around the entire circumference in accordance with the winding shape of the bare conductor. , Skill was required, and workability was extremely poor. In addition, the vicinity of the potential connection between the shield layer 4 and the high-voltage coils 1 and 2 needs to have a special structure such as avoiding winding of an insulator. Therefore, there was a drawback that the productivity was low and the production period was long. SUMMARY OF THE INVENTION It is an object of the present invention to provide a resin molded current transformer with high productivity, which increases the reliability of potential connection between a shield layer and a high-voltage coil and reduces the work of winding an insulator.

[0006]

According to the present invention, a low-voltage coil and a high-voltage coil wound on an iron core are molded with a synthetic resin, and the high-voltage coil is connected in series with a bare conductor and a bare conductor insulated and coated. The semiconductor device is characterized in that a semiconductive shield layer is arranged around the bare conductor and the insulated conductor.

[0007]

With this configuration, in the high-voltage coil, since the insulator of the insulated conductor is interposed between the windings of the bare conductor and the insulated conductor, a small current does not flow between the two conductors via the semiconductive shield layer. In addition, since the bare conductor is used for one of the conductors, the shield layer is in direct contact with the conductor and has the same potential, and the work of winding an insulator around the periphery is not required.

[0008]

FIG. 1 is a sectional view of a high-voltage coil which is an essential part of the present invention. The other configuration is the same as the conventional configuration, and the description is omitted. Among the high voltage coils 11 and 12, for example, the high voltage coil 11
Is a single-turned strip-shaped bare conductor, and the high-voltage coil 12 is formed of one or more turns of an insulated conductor obtained by winding the insulator 3 around the strip-shaped bare conductor. On the outer periphery of the high voltage coils 11 and 12, a shield layer 4 formed by winding semiconductive tapes having a high adhesiveness to a synthetic resin is formed.

In FIG. 1, the high-voltage coil 11 is not coated with an insulating coating, but the insulation from the high-voltage coil 12 is maintained by the insulator 3 of the high-voltage coil 12. Further, since the shield layer 4 is wound directly on the bare conductor of the high voltage coil 11, the shield layer 4 and the high voltage coil 11 are securely connected to each other over one turn and have the same potential.

Therefore, according to the above configuration, since the high-voltage coil 12 is an insulated conductor and the insulator 3 is interposed on the outer periphery, the two coils 11, 12 are interposed via the semiconductive shield layer 4.
No minute current flows between 12. And high voltage coil 1
1 uses the bare conductor as it is, so it is possible to remove the insulator on the outer periphery, require skilled skills, and reduce the amount of winding work of the insulator with poor workability, thereby improving productivity and shortening the production delivery time. It becomes possible. Furthermore, since the semiconductive shield layer 4 is wound around the bare conductor of the high voltage coil 11 over the entire circumference, the potential connection between the shield layer 4 and the high voltage coil 11 is ensured, and high reliability can be achieved.

[0011]

As described above, according to the present invention, a high-voltage coil has a configuration in which a bare conductor and an insulated covered conductor are connected in series, and a semiconductive shield layer is formed around the bare conductor and the insulated covered conductor. Is arranged, the reliability of the potential connection between the shield layer and the high-voltage coil is improved, and the winding operation of the insulator is reduced, so that a highly productive resin mold current transformer can be provided.

[Brief description of the drawings]

FIG. 1 is a sectional view of a high-voltage coil showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a resin mold current transformer.

FIG. 3 is a wiring diagram of a resin mold current transformer.

FIG. 4 is a sectional view of a conventional high-voltage coil.

[Explanation of symbols]

3 is an insulator, 4 is a shield layer, 5 and 6 are primary terminals, 7 is a synthetic resin, 8 is a low voltage coil, 9 is an iron core, 10 is a connection plate,
Reference numeral 11 denotes a high-voltage coil (bare conductor), and 12 denotes a high-voltage coil (bare conductor coated with insulation).

Claims (2)

(57) [Scope of request for utility model registration] 1. A low-voltage coil and a high-voltage coil wound on an iron core molded with a synthetic resin, wherein the high-voltage coil has a series connection configuration of a bare conductor and an insulating-coated bare conductor. A resin-molded current transformer comprising a semiconductive shield layer disposed on the outer periphery of a covered conductor. 2. The bare conductor is wound once, and the insulated conductor is wound one turn.
The resin mold current transformer according to claim 1, wherein the current transformer is configured as a wound winding or more.