Patent ID: 9129721
Filing Date: 2015-09-08
Classification: H01B,H02G

Abstract:
1. A direct current transmission system comprising an electrical conductor layer, an inner semiconductive layer circumferentially covering the conductor layer, an insulation layer provided on the outer circumference of the semiconductive layer comprising laminated polymer material having a total thickness and impregnated with a high viscosity fluid, which is solid below 65° C., and comprising an outer semiconductive layer circumferentially covering the insulation layer and providing an insulation layer/semiconductive layer interface, wherein the inner part is located from a first radial distance (r wherein the laminated polymer material within each one of the parts has a constant thickness and constant thickness ratio of polymer to laminated material, and wherein the inner part and outer part have a thickness ratio of polymer to laminated material between 5 and 25%, and wherein the middle part comprises laminated polymer material, wherein the thickness ratio of polymer to laminated material is more than 35%, and wherein the three parts have different densities such that a resistivity-governed E-stresses in the inner and outer part of the insulation material are lower compared with the resistivity-governed E-stresses in the middle part of the insulation material.