Impregnation of solid dielectric cable insulation. Final report

Technical Report · Tue Jul 01 04:00:00 EDT 1980

DOI:https://doi.org/10.2172/5194952· OSTI ID:5194952

Kiss, K. D.; Mangaraj, D.; Doepken, Jr., H. C.

Laboratory scale investigations were conducted to assess the feasibility of improving the dielectric characteristics of crosslinked polyethylene (XLPE) insulated cables rated 138 kV and above. Impregnation of slabs cut from 138 kV cables and of model cables with liquids increased the ac breakdown strength, presumably by filling the microvoids (and possibly in some cases acting as a voltage stabilizer) and preventing premature failure due to electrical discharge. The degree of improvement depends on the chemical nature of the impregnant. Vinyl toluene, styrene, styrene oxide and vinyl pyrrolidone were found to increase the dielectric strength substantially and in some cases improve the VT curve. With vinyl toluene, the improved strength is approximately 3750 V/mil compared to 2300 V/mil for the control. In situ polymerization with lauryl methacrylate and vinyl toluene monomers and impregnation with polyethylene wax have proven that the solid polymer is as effective as the liquid monomer. Optical and scanning electron microscopic examination supports the concept of void filling. The volume resistivity of semiconducting shields is not materially affected by the impregnation and polymerization, probably because the carbon black inhibits the polymerization. An economic analysis including raw materials' costs and manufacturing costs suggests that the process of impregnation and polymerization costs somewhat less than lead sheathed, dry cured power cables.

• Research Organization: Phelps Dodge Cable and Wire Co., Yonkers, NY (USA)
• OSTI ID: 5194952
• Report Number(s): EPRI-EL-1435
• 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
BREAKDOWN
CABLES
CONDUCTOR DEVICES
COST
DIELECTRIC PROPERTIES
ECONOMIC ANALYSIS
ECONOMICS
ELECTRIC CABLES
ELECTRICAL EQUIPMENT
ELECTRICAL INSULATION
ELECTRICAL PROPERTIES
EQUIPMENT
HVAC SYSTEMS
ORGANIC COMPOUNDS
ORGANIC POLYMERS
PERFORMANCE TESTING
PHYSICAL PROPERTIES
POLYETHYLENES
POLYMERS
POLYOLEFINS
POWER SYSTEMS
TESTING