Patent ID: 11876358
Assignee: NEXANS
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H  C | IPC C  H

Claim 0:
1. A method for creating a transition joint between two cables each having a conductor with a central wire surrounded by a plurality of layers of stranded wires wound about the central wire, said first and second cables being High Voltage Direct Current (HVDC) Mass Impregnated cables, wherein the method comprises the steps of:
a. providing two cables wherein the conductor of a first cable of said two cables is of smaller diameter than the conductor of a second cable of said two cables,
b. removing, from terminal portions of both of said first and second cables, any insulating layers or protective layers surrounding the conductors,
c. unwinding and pulling back in an upstream direction the plurality of layers of stranded wires of said first and second cables, thereby exposing ends of the central wires of said first and second cables,
d. thermally joining a connection piece between the ends of the central wires of said first and second cables,
e. rewinding and thermally joining the stranded wires of the plurality of layers of the first cable to the stranded wires of corresponding layers of the second cable such that:
each stranded wire of the first cable is abutted against, and joined end-to-end to, one stranded wire of said plurality of layers of stranded wires of the second cable, thus forming a flexible transition joint, and
when a layer of one of the first and second cables comprises more strands than a corresponding layer from the other of the first and second cables, two strands of the one of the first and second cables are abutted against, and joined directly at their ends thereof, to an end of one strand of the other of the first and second cables, a sufficient number of times to account for a difference in total strands, and
f. patching any insulating or protective layers about the flexible transition joint,
wherein the plurality of layers of stranded wires are wound in tandem in a spiral about the respective central wires of said first and second cables, with a horizontal distance required for a strand to pass through a same circumferential position defining a lay length of a layer, said method further comprising the steps of:
g. rewinding a first layer of strands of the first cable and cutting the strands such that ends of the first layer of strands of the first cable lay atop the connection piece in a row, extending linearly along an axial length of said flexible transition joint, corresponding to the lay length,
h. rewinding a first layer of strands of the second cable and cutting the strands such that ends of the first layer of strands of the second layer lay adjacent corresponding ends of the first layer of strands from the first cable,
i. thermally joining the ends of the first and second layer of strands, and
j. performing steps g-i for remaining layers of the plurality of layers for each of the first and second cables.