In severe cold weather, ice dancing, overload, ice flash easily lead to the following failure:
(1) conductor galloping on transmission line under ice, causing damage to the line equipment;
(2) the ice melts, easily formed on the surface of the ice bridge insulator, if the insulator pollution is serious, prone to icing flashover;
(3) the lead wire icing overload, which will cause the tower head compression yield deformation and inverted tower line and other accidents.
In view of the above situation, the main measures to be taken are as follows.
(1) dance control. In line dancing section installed anti galloping device, improve the threshold of dancing, effectively inhibit the galloping amplitudes and strength, also on the galloping section in the dual string (porcelain or glass insulators per installed a set of insulators on spacer for support to prevent double insulator strings for dancing collision damage (UHV situation slightly better).
(2) the prevention and control of ice flashover. One is to take in clusters of, namely in the middle of each string of insulators, every 3 (or 5) in a piece of straw hat type large diameter insulator, in order to achieve prevent insulator string on the ice bridge, preventing ice flashover; the second is the insulator inverted V on, between conductor and tower air gap unchanged under the premise in order to ensure the can extended the length of the insulator string, increasing the insulation strength.
(3) the main measures taken to deal with the accident of the power grid safety, such as the yield of the ground wire bracket caused by the overload of the ice covering, the ground wire series, the disconnection of the lead wire and so on:
The increase of the wire, fittings and other equipment to prevent the wire breaking strength, ground movement, slip line;
The local reinforcement of tower components, such as strengthening the ground frame;
To shorten the length of the wire and improve the stress condition.
(4) the key section of the installation of online monitoring devices, but also should be a long-term manual observation, the accumulation of data to guide the future of anti icing work.
