Application of low temperature technology to power transformers

Technical Report · Mon Feb 01 04:00:00 EST 1982

OSTI ID:5343872

A detailed conceptual design has been developed for a 1000 MVA, 500/22 kV line-to-line, 1300 BIL power transformer which uses superconducting windings. The design uses a multiple winding configuration which is current limiting under fault conditions. The conductor is a multifilamentary braid or cable, with strand and filament diameters near the limits of the state of the art (100 ..mu..m and 0.5 ..mu..m respectively). This conductor design and winding configuration result in very low ac losses. The efficiency of the superconducting transformer is 99.85% as compared to 99.7% for conventional power transformers. The input power requirements of the refrigeration equipment are considered as a loss for efficiency determination. The savings in the cost of lossesover the the life of the transformer provide the economic-feasibility of this design approach. A conceptual design for the insulation system using supercritical helium at 6 atmospheres in conjunction with plastic and fiberglass components is presented. These selected materials have low-loss tangents, so that dielectric losses in the cold space are kept to very low levels. Fiberglass is used in the construction of the winding formers and the non-conducting vacuum insulated, cryostat, which also employs a nitrogen-cooled radiation shield. The thermal analysis indicates that adequate cooling is available for normal operation, and that a critical problem exists during and after short-circuit transients. This critial problem remains unsolved. The Reliability Studies did not identify any problems in this area. An Environmental Impact Study found that the superconducting transformer does not present identifiable environmental concerns.

• Research Organization: Westinghouse Electric Corp., Pittsburgh, PA (USA)
• DOE Contract Number: AC01-78ET29324
• OSTI ID: 5343872
• Report Number(s): DOE/ET/29324-1; ON: DE82009296
• Country of Publication: United States
• Language: English

Related Subjects

200301* -- Power Transmission & Distribution-- AC Systems
EHV & UHV-- (-1989)
24 POWER TRANSMISSION AND DISTRIBUTION
420201 -- Engineering-- Cryogenic Equipment & Devices
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AC LOSSES
AC SYSTEMS
CONTROL EQUIPMENT
CRYOSTATS
DESIGN
ECONOMIC ANALYSIS
ECONOMICS
EFFICIENCY
EHV AC SYSTEMS
ELECTRICAL EQUIPMENT
ELECTRICAL INSULATION
ELEMENTS
ENERGY LOSSES
ENERGY SYSTEMS
EQUIPMENT
FLUIDS
GASES
HELIUM
LOSSES
NONMETALS
POWER SYSTEMS
RARE GASES
SUPERCONDUCTING COILS
THERMAL INSULATION
THERMOSTATS
TRANSFORMERS