Current transmission system for HVDC including a solid insulator having a surface coating of resin containing chromium oxide or iron oxide
US4688142A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 14, 1986 |
| Grant date | Aug 18, 1987 |
| Priority date | — |
| Expiry date | Oct 14, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02G5/063
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A system for HVDC transmission comprises a conductor, stressed by d.c. voltage, which is insulated from a surrounded grounded casing by pressurized SF.sub.6 gas and along part of its length by at least one solid insulator supporting the conductor in the casing and in contact with the gas. By designing the solid insulator as a core of solid insulating material and a coating, provided thereon, with a high surface resistance, it is possible considerably to reduce the dimensions of the casing. The coating consists of a resinous binder containing a powdered filler in the form of chromium oxide or iron oxide, or a mixture of these substances. The coating preferably has a surface resistance between 10.sup.12 and 10.sup.18 ohm/.quadrature. at an electric field strength of 1 kV/mm.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.