DE3232704C2 - Primary conductor, especially for single-conductor cast resin current transformers - Google Patents

Abstract

A primary conductor, especially for single-conductor cast resin current transformers, should be designed in such a way that it has the required inherent stability despite relatively simple manufacture, can be easily threaded onto a toroidal core and the insulation path between the primary conductor and core with secondary winding meets the electrical requirements. For this purpose, the primary conductor (1) is composed of individual strips and is spatially concentrated in its central part (2) by means of a V-shaped embossing. To apply the core (4), one of the legs (3) can be bent open.

Description

15th

The invention relates to a primary conductor according to the preamble of the single claim.

It is assumed to be known to design primary conductors for single-conductor current transformers as stranded conductors, which in known constructions were introduced into porcelain insulators. However, stranded conductors are not inherently stable and therefore cannot be used for cast resin converters. Stranded conductors also have a poor fill factor and require high material costs. Furthermore, they are very difficult to contact.

From DE-AS 23 36 520 a top current transformer is known in which two primary conductors are provided which enforce the core window. The primary conductors can be switched to two different dimensional ranges. The two Primary conductors are twisted against one another within and along the core window. In a special one Execution, each primary conductor is bent at one end, while the other end is straight. The two primary conductors can have a rail profile.

From DE-OS 22 23 437 a current transformer is known in which the primary conductor, in particular from a Tube consisting, is tapered in the area of the current transformer strip core.

From the article "Status of the electrical engineering cast resin application" by A. Imhof in the magazine "ETZ-A" Volume 78 (1957) Issue 11, pages 384-389 is a cast resin backup current transformer from Figure 3 there known in which the central part of the primary conductor is encompassed by the current transformer core and the primary conductor has legs bent at right angles.

It is known from DD-PS 28 705 a primary winding of a current transformer, which consists of at least two There is copper or aluminum strips on top of one another and connected in parallel.

The invention is based on the object of providing a primary conductor, in particular for single-conductor cast resin current transformers to be designed in such a way that it has the necessary inherent stability despite its relatively simple manufacture, can easily be threaded onto toroidal cores and in which the insulation distance between the primary conductor and core is also included Secondary winding meets the electrical requirements.

The object on which the invention is based is achieved by the features characterized in the claim.

In the following the invention is based on an exemplary embodiment explained in more detail.

The single figure shows a primary conductor 1 for single-conductor cast resin current transformers, which is composed of individual bands. Included in the current transformer core 4 In the middle part 2, the primary conductor 1 is embossed in a V-shape. The V-shaped embossing in the middle part 2 is the primary conductor 1 spatially concentrated in such a way that the required insulation distance between core 4 and Primary conductor 1, which can be filled, for example, with cast resin, is created. During the embossing process the two legs 3 of the primary conductor 1 are bent at right angles. To apply the core 4 are the bands of a leg 3 are bent open so far into the position shown by dashed lines that the core 4 can easily slide open. The requirement that the clear width of the toroidal core 4 mechanically still allows it to be pushed onto the tape package. After the core 4 has been applied, it is bent Legs bent back again, this optionally being able to be done individually band by band.

The invention results in an inherently stable winding. The embossing process can be carried out inexpensively. The handling when bending one leg up and down requires little force because the bands can be bent individually if necessary.

1 sheet of drawings

Claims (1)

Claim: Primary conductor, especially for single-conductor cast resin current transformers, with a central part encompassed by the current transformer core and legs bent at right angles, characterized in that the primary conductor (1) is composed of a series of closely spaced strips, in its central part (2) spatially concentrated without changing the cross-section of the bands by V-shaped embossing and one of the legs (3) can be bent open for attaching the toroidal core (4). 10