High-temperature gas-insulated systems. Final report

Technical Report · Fri Aug 01 04:00:00 EDT 1980

DOI:https://doi.org/10.2172/5285098· OSTI ID:5285098

Dethlefsen, R.; Tahiliani, V.; Hughes, P.; Cronin, J.

The economic impact of, and the technical requirements for, high temperature operation (140/sup 0/C) of SF/sub 6/-insulated transmission lines are analyzed. Optimized design computer programs incorporate the present worth cost of losses. The cost of losses makes it uneconomic to raise the conductor temperature beyond about 110/sup 0/C. For the same reason forced cooling is not attractive for steady operation. High temperature operation and forced cooling are attractive for operating flexibility by allowing higher short-term loading. Components for high temperature operation were developed and tested. These are insulators, conductor joints, and spiral-welded enclosures. A 9 m (30 ft.) long section of a 362-kV prototype was built and tested in three modes of installation: open air, covered trench, and direct burial. The steady state and transient ampacity for high temperature operation were measured and compared with calculated data. Thermal radiation accounts for about 15% of the conductor-enclosure heat transfer. High emissivity paint on the interior surfaces can increase the radiative heat transfer by a factor up to six. Forced cooling by circulating the SF/sub 6/ gas is practical only for short lines up to 1/2 mile. The prototype enclosure was water cooled by strapping four aluminum tubes to the outside. This increased the buried mode ampacity by only about 50% because the thermal resistance between enclosure and water pipes proved to be to high. Ampacity correction factors for various installation parameters are summarized in the Application Guide of Section 5.

• Research Organization: Gould-Brown Boveri, Greensburg, PA (USA)
• OSTI ID: 5285098
• Report Number(s): EPRI-EL-1500
• Country of Publication: United States
• Language: English

Related Subjects

200301* -- Power Transmission & Distribution-- AC Systems
EHV & UHV-- (-1989)
24 POWER TRANSMISSION AND DISTRIBUTION
AC SYSTEMS
CABLES
CONDUCTOR DEVICES
COOLING
COST
DATA
ECONOMICS
EHV AC SYSTEMS
ELECTRIC CABLES
ELECTRICAL EQUIPMENT
EQUIPMENT
EXPERIMENTAL DATA
FLUORIDES
FLUORINE COMPOUNDS
GAS-INSULATED CABLES
HALIDES
HALOGEN COMPOUNDS
HIGH TEMPERATURE
INFORMATION
NUMERICAL DATA
OPERATING COST
PERFORMANCE TESTING
POWER SYSTEMS
POWER TRANSMISSION
SULFUR COMPOUNDS
SULFUR FLUORIDES
TESTING
UNDERGROUND POWER TRANSMISSION