Resistive cryogenic cable, Phase III. Final report

Technical Report · Sat Oct 01 04:00:00 EDT 1977

DOI:https://doi.org/10.2172/5234378· OSTI ID:5234378

This project was undertaken to design, fabricate and test components of an ac resistive cryogenic cable system. Fiber reinforced plastic was considered to be the most promising pipe material. Cellulose paper was selected for use as the dielectric in the cable samples tested. Instead of the more complex and expensive vacuum multilayered thermal barrier around the liquid nitrogen containment pipe, a closed cell polyurethane foam thermal insulation was chosen as a more desirable envelope. A half-scale sample of pipe with adhesive joints passed all permeation and thermal/pressure cycling tests. Sections of cable were electrically tested for breakdown stress under step stress testing. Conductors were insulated with a wall of cellulose paper and impregnated with liquid nitrogen (LN/sub 2/). The breakdown data from the 550-mil cables indicated a breakdown strength greater than 860 Volts/mil (33.9 kV/mm). The 860-mil insulated cable was not failed electrically; however, due to premature failure which initiated in the capacitor stack of the pothead, further testing of this cable was prevented. Conventional volt-time dielectric aging studies show that LN/sub 2/ impregnated cellulose paper exhibits excellent properties. Step stress tests were conducted using 1/4-, 1-, and 4-hour steps; the voltage was raised in increments of 2.5 kV. A cable design study was performed in order to characterize the cost of fabricating, installing, and utilizing a resistive cryogenic system of 2000- to 5000/MVA capacity. Based on a 20-mile urban/suburban scenario used in this study and on the chosen cable parameters of a 500-kV operating voltage, a 3500/MVA capacity, and a fiber reinforced plastic and polyurethane foam insulated envelope, the system costs were between $1,973/MVA-mile and $2,100-MVA-mile, depending on layout and geometry of circuits. It is concluded that more confidence is needed before embarking on a development effort for a full-scale system.

• Research Organization: General Electric Co., Schenectady, N.Y. (USA). Power Generation and Propulsion Lab.
• OSTI ID: 5234378
• Report Number(s): EPRI-EL-503
• Country of Publication: United States
• Language: English

Related Subjects

200303* -- Power Transmission & Distribution-- Superconducting & Cryogenic Systems-- (-1989)
24 POWER TRANSMISSION AND DISTRIBUTION
AC SYSTEMS
BREAKDOWN
CABLES
CONDUCTOR DEVICES
COST
CRYOGENIC CABLES
CRYOGENIC FLUIDS
DESIGN
EHV AC SYSTEMS
ELECTRIC CABLES
ELECTRICAL EQUIPMENT
ELECTRICAL INSULATION
ELEMENTS
EQUIPMENT
FABRICATION
FLUIDS
NITROGEN
NONMETALS
ORGANIC COMPOUNDS
ORGANIC POLYMERS
PAPER
PERFORMANCE TESTING
PETROCHEMICALS
PETROLEUM PRODUCTS
PLASTICS
POLYAMIDES
POLYMERS
POLYURETHANES
POWER SYSTEMS
POWER TRANSMISSION
TEST FACILITIES
TESTING
THERMAL INSULATION
UNDERGROUND POWER TRANSMISSION