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Title: Some characteristics of dielectric materials at cryogenic temperatures for HVDC systems

Journal Article · · IEEE Trans. Electr. Insul.; (United States)

This dielectric study was performed as part of the dc Superconducting Power Transmission Line Program. During a screening test program, the dc breakdown strength of 12 dielectric materials, in sheet form, was determined at 12 K under 1.38 MPa of helium pressure, the operating conditions of the cable design. Tests were also made with four of these materials impregnated with mineral oil. Further dc breakdown tests were performed on five of these dielectric materials at various temperatures (12 to 298 K) and pressures (0.69 and 1.38 MPa) of helium. Two sets of experiments were performed on cellulose paper impregnated with distilled water at 83 K and 1.38 MPa of helium pressure. Five dielectric materials were then selected for tests as cable samples with dc and impulse voltages at 12 K and 1.38 MPa of helium. Data are presented on these tests, as well as on those of the electrical conductivity of four dielectric materials at cryogenic temperatures, and of the surface flashover strength of an epoxy bushing at 12 K and 298 K under 0.69 MPa and 1.38 MPa of helium pressures. The characteristics of the dielectric behavior at cryogenic temperatures are discussed.

Research Organization:
Los Alamos Scientific Lab., NM
OSTI ID:
5712891
Journal Information:
IEEE Trans. Electr. Insul.; (United States), Vol. EI-16:1
Country of Publication:
United States
Language:
English