Research On Construction Technology For Exchanging Blackout Wire In The Double-circuit 220kv Overhead Transmission Lines

There are more than 4000 kilometers of extra-high voltage transmission lines in the Shanghai power grid. Frequently, when we rebuilt the extra-high voltage transmission lines, the conductors should be exchanged, while the steel tower will be reserved. When we exchange the wire of the double-circuit 220kv overhead transmission lines, the both loops are blackout. The reliability of power supply will be reduced.This paper describes the research on construction technology for exchanging blackout side wire in the double-circuit 220kv overhead transmission lines, when one loop is blackout and the other loop is still in use. In order to avoid affecting the grid due to the outage of both of double-circuit transmission lines and improve the reliability and economy of power supply, we have solved a series of technical difficulties such as the calculation and setting of wire stress, the way how to connect the new wires and the insulating rope to the old wires, the style of fittings, how to adjust the position of the wheel, the problem of static induction, developed and improved a number of new equipments, originally used high-strength insulating rope, the special hauling and tensional machine and rope pulley block of insulation, etc. We also developed the new technology and formulated corresponding construction plan and operating instructions. This technology proved to be benefit to the reliability and economy of energy supply when an important project has be completed successfully.