| 摘要 |
PURPOSE:To enable measurement of the position of a three-core power cable even when no power protection signal line is incorporated therein, by connecting a current-controlling element to each of two cores at one end of the cable and connecting another current-controlling element to the third core at the other end thereof. CONSTITUTION:A three-core power cable has power cores 1A, 1B and 1C and the cable part 2 thereof is buried in the seabed or the like. Capacitors C1 and C2 are connected between the power cores 1A and 1B and the earth on the power supply side, while a capacitor C3 is connected between the power core 1C and the earth on the load side. Currents ia+io, ib+io and ic+io are supplied from a three-phase AC power source to power cores 1A, 1B and 1C respectively and a current io is made to flow to the earth through the intermediary of the capacitors C1,C2 and C3. A current flowing through each of the power cores 1A, 1B and 1C turns to be ia,ib and ic+io respectively in the cable part 2, i.e. to be placed in a state of imbalance. Accordingly, the position of the part can be measured by a search coil or the like. |
