Development of radial-flow type internally oil-cooled oil-filled cable

A radial-flow type, internally oil-cooled, oil filled, paper-insulated cable has been developed. The oil flows radially through the paper insulation, decreasing the thermal resistance of the insulation. The decreased thermal resistance as well as the cooling effect of the oil flow in the central oil duct and the outer oil duct under an aluminum sheath increase the current capacity. A method for calculating the cooling characteristics is introduced. The results of initial electrical tests and a long-term field test, confirming the stability of the cable and accessories, are presented.<
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