Large cross-sections and composite screens design

The core of large cross-section HV and EHV extruded cables are genarally segmental, to reduce losses due to the skin effect. The TB gives details on both theoritical and experimental approach, from which the WG could propose recommendations for evaluating the a.c. resistance of these cores, to be taken into account when calculating the cable current carrying capacity. It describes the calculations of losses in composite screens, combination of a bundle of wires and a metallic sheath (or a foil) and proposes a method of calculating the permissible short-circuit current of this kind of metallic screens.