Electric power transmission cable particularly for an overhead line

摘要

The invention concerns an electric power transmission cable, particularly for an overhead power line, comprising at least one central composite ring (1) formed of fibers impregnated by a matrix, of which the specific breaking strength is greater than 0.4 MPa·m3/kg and at least one layer of conductive wires (3) nested within one another, made of aluminum or an aluminum alloy and windings around said ring (1), said cable having an outer diameter at ambient temperature called the initial diameter (Di) and the ratio between the thermal expansion coefficient of the conductive wires (3) and that of the central ring (1) is greater than three. According to the invention, said conductive wires (3) nested within one another are of a geometry such that the increase in the outer diameter of one length of said cable shorter than 45 m, during an increase of temperature lasting two to four minutes, from ambient temperature to a temperature between 150 and 240° C., is less than or equal to 10% of the initial diameter (Di), said cable being subject to a mechanical tension between 10% and 30% of the nominal breaking strength of the cable. The invention also concerns a conductive wire geometry enabling such a level of expansion of the diameter.

主权项

1. Electric power transmission cable comprising:
at least one central composite core having fibers impregnated by a matrix and the specific strength of which is greater than 0.4 MPa·m3/kg and at least one layer of mutually interlocking conductive wires, made of aluminum or of an aluminum alloy and wound around this core, said cable having an external diameter at ambient temperature that is referred to as the initial diameter (Di) and the ratio between the thermal expansion coefficient of the conductive wires and that of the central core is greater than three, cable for which each said mutually interlocking conductive wire has a side referred to as an upper side and a side referred to as a lower side that are positioned over a circular geometric cylinder having as longitudinal axis the longitudinal axis (A-A) of the cable and as radius Rs and Ri, wherein the width (L) of each said conductive wire at the intersection of a circular geometric cylinder of the same longitudinal axis (A-A) and of radius ½ (Rs+Ri) is between 80% and 120% of the difference (Rs−Ri).