Extruded dielectric dc cable development. Final report
The development of an extruded 100-kilovolt (kV), direct-current (dc) cable insulated with mineral-filled polymeric dielectrics is described. Analysis of the factors controlling the rated stress and load limits indicated that capabilities of an extruded dc cable could be improved by reducing the dependency of electrical resistivity on temperature and the thermal resistivity of the dielectrics. It was experimentally determined that these two properties of extrudable polymers can be suitably modified by introduction of mineral fillers. Insulation efforts produced a family of candidate compounds exhibiting the desirable characteristics. Screening tests conducted on slab samples, insulated wires, and full-size experimental cables resulted in selecting a mineral-filled, cross-linked polyethylene compound, and a prototype 100-kV dc cable was manufactured. In addition to the the mineral-filled prototype, a reference cable insulated with conventional unfilled cross-linked polyethylene was made. Both cables were designed to meet the same operational requirements. The prototype and reference cables, connected in series, were subjected to the CIGRE dc cable qualification test, but failed it. However, the posttest examination disclosed multiple punctures in both cables, and it was not possible to conclude which cable initiated the failure of the series-connected cable system. The unfilled polyethylene reference cable was then retested alone and failed. Because of insufficient quantity of the original prototype, a mineral-filled, 35-kV ac cable from commercial production was selected as a substitute and subjected to and passed the CIGRE test. These results indicate that a mineral-filled, cross-linked polyethylene compound is a promising dielectric for extruded dc-power cable application.
- Research Organization:
- General Electric Co., Bridgeport, CT (USA)
- OSTI ID:
- 5319022
- Report Number(s):
- EPRI-EL-1386
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
24 POWER TRANSMISSION AND DISTRIBUTION
BREAKDOWN
CABLES
CONDUCTOR DEVICES
DC SYSTEMS
DIELECTRIC MATERIALS
ELECTRIC CABLES
ELECTRICAL EQUIPMENT
ELECTRICAL INSULATION
EQUIPMENT
EXTRUSION
FABRICATION
HVDC SYSTEMS
MANUFACTURING
MATERIALS
MATERIALS WORKING
ORGANIC COMPOUNDS
ORGANIC POLYMERS
PERFORMANCE TESTING
POLYETHYLENES
POLYMERS
POLYOLEFINS
POWER SYSTEMS
TESTING