INSULATED ELECTRIC CABLE

摘要

An electric cable of the mass-impregnated non-draining type impregnated with a dielectric impregnating material. The dielectric impregnating material is liquid and the viscosity of the liquid impregnating material exhibits a low temperature dependency that gives the cable pressure dynamic properties, whereby it acquires a capability to accommodate and compensate for thermal and pressure gradients building up in the cable under operation. The acquired pressure dynamic properties minimize the risks of unfilled voids and the like discontinuities developing. At the lower range of operating temperatures, the dielectric liquid has a viscosity suitably high to ensure the non-draining features while it allows the liquid to flow under the influence of shear stresses typically developing in the radial direction in the cable insulation of a DC cable during operation. Further, the impregnating material, within the first lower range of temperatures, exhibits a minimized weak temperature dependency of the viscosity. At a higher range of impregnating temperature, it has a significantly lower viscosity to ensure the impregnation result. It exhibits a significant change in the viscosity over the limited transition range of temperatures.