DE2739600A1 - Cylindrical HV cable termination made of elastomer - contains field controlling additive substance within elastomer sheath without additive - Google Patents

Abstract

A cylindrical h.v. cable termination is made of a flexible elastomer contg. a finely-divided substance to control the field. The field-controlling substance(s) is e.g. titanium dioxide, magnesium titanate or barium titanate or silicon carbide. The elastomer contg. the field controlling substance is enclosed in an elastomer sheath contg. no additive. Two or more cylindrical tubular pieces are arranged behind each other and connected electrically with one another.

Description

Cable termination

The invention relates to a prefabricated slide-on cable termination made of flexible elastomers. Cable terminations of this type usually iron one Rotation bodies with a central passage and are dimensioned so that they with Preload can be pushed onto the prepared cable end.

Terminations are required to terminate high-voltage cables, which are equipped with field control elements.

The field control elements are control electrodes made of metal or semiconducting materials, such as rubber or plastic compounds made conductive with carbon black known. From electrical Reasons is the geometric shape of the Field control elements specified. Usually the field control electrodes are dac funnel-shaped. It is obvious that the geometric Dimensions of this end closure are essentially determined. The installation of a field control funnel therefore requires an increased space requirement for the end closure.

The known terminations contain parts made of different material. This makes the production cost relatively high. To such a termination manufacture, nut than initially manufactured the field control funnel and replicated be switched. Only then can the end closure be manufactured in a further operation will.

The present invention has for its object to iron for high-voltage kane Cable termination of the type mentioned with more favorable geometric dimensions which can be produced with little material expenditure and installed in a space-saving manner can and still has field-controlling properties. He should also be on as much as possible can be produced in a simple manner and be easy to assemble.

This object is achieved according to the invention in that the flexible Field-controlling substances are added to elastomers in finely divided form.

Mixtures are usually used for cable terminations of this type flexible elastomers are e.g. silicone rubber, Athfier propylene rubber, polychloroprene, chlorosulfonerte @@@@@@@@@@@, 3ty = olbutadiene rubber, natural rubber, ethylene venyl acetate rubber, Ethylene acrylate rubber.

According to the invention, substances are added to these mixtures which increase the dielectric constant of these mixtures and at the same time do not linear current / voltage characteristics (ie: i Materials set. These two effects effect a control of the electric field in the area of the end closure. Due to the doping of the end closure for the production of the invention used flexible elastomers with field-controlling substances results in a extensive field control. A field control funnel is on the invention End closure not required for Felo control.

The field-controlling substances according to the invention are flexible Elastomers in finely divided form Titanium compounds such as titanium dioxide, magnesium titanate or barium titanate added.

Also an admixture of silicon carbide to the flexible elastomers acts in a field-controlling manner in the sense according to the invention.

The use of the mixtures according to the invention for the construction of a prefabricated slide-on cable termination makes it possible to use the termination to give relatively small geometric dimensions. So the end closure according to the invention as a cylindrical Be formed pipe section. To make things easier the cable-side end of the portage can be widened axially to such an extent that it can be pushed over the shield wires bent back over the cable sheath. At higher voltages, two oc: cr more cylindrical pipe sections can be axially behind one another be arranged on the cable core and electrically connected to one another. E: Ease of assembly of the end closure according to the invention proves particularly when it is used in outdoor cable terminations. Here this termination can simply be inserted into the already Verseherer with a foot fitting and with an insulating filling.

Open-air isolator can be inserted.

To increase the surface resistance, the inventive End closure be coated with an outer pure silicone rubber layer, which does not contain any field-controlling substances, the cable termination according to the invention has the advantage that its geometric dimensions are relatively small. Its diameter is not significantly larger than that of the cable end to be terminated, since it does not have a Has field control funnel. The termination can therefore be used with advantage for compact stations can be used. It also offers the further advantage that it is suitable for the Control of higher stresses by joining multiple parts axially as required long can be built up. The manufacture of the end closure according to the invention requires little material and can be done in a single operation. she is therefore very easy.

Exemplary embodiments of the end closure according to the invention are shown in shown in the drawing. Figures 1 and 2 show two different application examples.

The end closure according to the invention is denoted by 1 in the figures. It consists of flexible elastomers that are doped with field-controlling substances :; ind. Because of this material, the end closure is as shown designed as a cylindrical pipe section. He is on the insulation 4 of the conductor 3 postponed. The cable-side end of the end closure has a radial widening 8, which is pushed over the Schirdränte 6, which over the jacket 7 of the cable are bent back. The termination is so with the shield wires and the outer Conductive layer 5 in electrical contact. The cable is marked with 10 and in the drawing the twisted shield wires are designated by 9. About the maintenance conditions of the sealing end for various applications, e.g. in damp interiors or when dirt accumulates To improve it, it has a layer 2 of the pure flexible on its outside Elastomers without the addition of field-controlling substances (Figure 1). This will make the The surface resistance of the termination is increased to such an extent that it is maintenance-free Plants can be used.

Figure 2 shows a termination for use on cables for higher Tensions. In this case, two cylindrical pipe pieces 1 and 1 'are axially behind one another pushed onto the cable core. The electrical connection of these pipe sections takes place in the case illustrated via the connecting hose 11, which is also consists of doped elastomers and with pretension on the connection point is upset. The connecting hose 1i can also be shrunk on if necessary. If pipe sections with cable-side expansions 8 are used, their electrical Connection by sliding the widening onto the forehead edges of the previous one Pipe sections produced under prestress. Di2 end closures shown in the figures can also easily be provided with insulator sleeves for outdoor use which can also contain an insulating filling. ie layer 2 of the pure flexible elastomers (see FIG. 1) is not required in this case.

The figures clearly show that the diameter of the invention End closure is not significantly larger than the Xabel diameter. That will go through the proposed special choice of material achieved that dispenses with a conventional Radiation funnel, which significantly increases the dimensions of the termination would be made possible.

This fact allows for outdoor applications that are already based on the Cable ends pushed pipe pieces 1 and 1 'in a simple manner and very easy to assemble by means of a seal in a cover provided with a foot fitting (e.g. from Porcelain), which already contains an insulating filling.

8 claims 6 pages description 2 sheets of drawings with two characters L e r s e i t e

Claims (8)

Claims Prefabricated slide-on cable termination made of flexible Elastomers, characterized. that the flexible elastomer in finely divided form field-controlling Substances are mixed in. 2. End closure according to claim 1, o thus qekernzeich that the flexible Elastomers as field-controlling additives Titanium compounds such as titanium dioxide, magnesium titanate, Ba @@@@@ titanat are added in finely divided form. 3. End closure according to claim 1, characterized. d33 the flexible elastomer as field-controlling substance silicon carbide is mixed in in a finely divided form. 4. End closure according to one of claims 1 to 3, characterized. that it uses a layer of flexible elastomer with no additional field-controlling Substances is coated. 5. End closure according to one of claims 1 to 4, characterized in that that it is designed as a cylindrical piece of pipe. O. End closure according to claim 5, characterized in that its cable-side end is widened axially so far that it is over the cable sheath bent back shield wires can be pushed. 7. End closure according to claim 5 or 6, characterized1 dan two or more cylindrical pipe sections arranged axially one behind the other on the cable core and. are electrically connected to one another. 8. End closure according to one of claims 1 to 3 or 5 to 7, characterized marked. that it is in an outdoor insulator that was previously provided with insulating filling is inserted.