| 摘要 |
PURPOSE:To reduce the sheath loss and to facilitate the control of a system, by transposing single-core cables included in every three spans from one side of the cables, and by arranging every three joints as ordinary joints in which the sheaths are not grounded while arranging the other joints as insulating joints in which the sheaths are cross-bonded. CONSTITUTION:Single-core cables 1A, 1B and 1C through which three-phase AC current is transmitted have cable terminals 2A, 2B, 2C and 2'A, 2'B, 2'C each of which is grounded. Each single-core cable is provided with eight joints 3J1, 3J2, 3J3, 3J4, 3J5, 3J6, 3J7 and 3J8, and hence it is divided into nine spans. The single-core cables included in every third span from the cable terminals 2A, 2B and 2C, namely in the spans between the joints 3J2 and 3J3 and between the joints 3J5 and 3J6 are transposed. Among the joints 3J1-J8, every three joints from the cable terminals 2A, 2B and 2C, i.e. the joints 3J3 and 3J6 are not grounded but arranged as ordinary joints of the single-core cables 1A, 1B and 1C. The other joints 3J1, 3J2, 3J4, 3J5, 3J7 and 3J8 are arranged as insulating joints in which sheaths of the cables are cross-bonded. |
