Patent · US Expired

Insulation of metallic surfaces in power transformers

US4639282A · kind A · utility

5Cited by
7References
14Claims
0Family size

Assignee

Inventor

Key dates

Filing dateFeb 18, 1986
Grant dateJan 27, 1987
Priority date
Expiry dateFeb 18, 2006

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH01F27/36
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

Abstract

A method for improving the electrical insulation of an electrode in a power transformer included in a converter plant of a high voltage direct current (HVDC) transmission system. The method involves winding around the electrode, layers of tape of woven or non-woven fibrous structure of non-conducting cellulose material, inorganic plastics material, or inorganic insulating material. This means that ions approaching the electrode, which are migrating under the influence of a high d.c. field outside the electrodes, do not sense the porous tape insulation as any noticeable obstacle, while at the same time the insulating layer is sufficiently dense to increase the breakdown value in the case of electrical surges.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.