Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
  • H01B17/00—Insulators or insulating bodies characterised by their form
  • H01B17/56—Insulating bodies
  • H01B17/60—Composite insulating bodies
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
  • H01B17/00—Insulators or insulating bodies characterised by their form
  • H01B17/32—Single insulators consisting of two or more dissimilar insulating bodies

Definitions

• the invention relates to an insulating cylinder according to the preamble of the claim.
• Such insulating material cylinders are usually designed as a hollow winding body, namely the winding is applied dry to a winding mandrel, after which the whole comes in a closed cylindrical shape and is evacuated, in order to then be filled with epoxy resin. Either continuous threads or fabric webs are used as the winding material.
• This method can be used to manufacture high-quality insulating cylinders with particularly high mechanical strength.
• it is often not only the mechanical stress on the winding hollow body that is important, but rather special dielectric stresses are added to the mechanical stress, in particular if contacts of different electrical potential are located at different points in the cylinder wall. The voltage stress between the individual contacts plays a special role here.
• the object of the invention is to improve the insulating cylinder mentioned at the outset in such a way that the cylinder wall has, in addition to sufficient mechanical strength, above all a high dielectric strength for as many directions as possible. This object is achieved by the means specified in the characterizing part of the claim.
• the invention is based on the fact that the wall of an insulating cylinder made of epoxy resin with a ge wrapped reinforcement made of glass fibers, which has hardened under vacuum, can not be regarded as a homogeneous insulating material. With such a material, the dielectric strength must be seen depending on the direction of stress. Two directions of stress are to be considered, namely the stress in the fiber direction and the stress transverse to the fiber direction. The stress in the fiber direction will always result in less favorable values than a stress in the cross-grain direction. The reason for this is to be seen in the fact that individual threads are sometimes not properly wetted by the resin and this can lead to directional breakdown channels along the threads between two points of different potential.
• the wound reinforcement is now made exclusively from a multi-layer wound glass fiber mat, which has a fiber structure made of short undirected fibers, there can no longer be a direct channel formation between metal parts of different potentials. It is essential that this applies to all directions due to the undirected short fibers. For an occasionally irregular arrangement of contacts with different potentials in the cylinder wall, it is therefore no longer necessary to take particular account of whether the dielectric stress occurs transversely to the fiber or along the fiber.
• the advantage achieved with the invention is therefore to be seen in the fact that overall the dielectric strength of the cylinder wall is improved for any direction. In other words, when arranging contacts in the cylinder wall, the fiber course of the reinforcement no longer needs to be given special consideration.
• a preferred application of the invention are, for example Insulating cylinder for tap changers of step transformers, specifically insulating cylinders as a supporting structure for the fixed step contacts of a step selector. If you want to carry out the supporting structure of such a tap changer - which is usually designed as a cage made of insulating rods - as a closed insulating cylinder, then there are considerable problems with regard to the dielectric stress on the insulating material due to the large number of fixed tap contacts to be arranged with different potentials. In the case of an insulating material cylinder wound with continuous threads, it can practically not be avoided that the wound threads run directly from one step contact to the other, so that the dielectric strength of the insulating material is then no longer sufficient.

Landscapes

• Insulating Of Coils (AREA)
• Insulating Bodies (AREA)
• Laminated Bodies (AREA)
• Inorganic Insulating Materials (AREA)
• Glass Compositions (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (3)

Family

ID=6212199

Family Applications (1)

Country Status (4)

Cited By (1)

Families Citing this family (3)

Family Cites Families (3)

• 1983
  • 1983-10-19 DE DE19833337954 patent/DE3337954A1/de active Granted
• 1984
  • 1984-10-09 AT AT84112064T patent/ATE62352T1/de not_active IP Right Cessation
  • 1984-10-09 EP EP84112064A patent/EP0141303B1/fr not_active Expired - Lifetime
  • 1984-10-18 JP JP59217475A patent/JPS60101817A/ja active Granted

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