OPGW Insulation Design for Energy Efficiency Improvement and Ground Wire Ice Melting

The insulation design of OPGW for overhead ground wire of transmission line can reduce power loss and can be used for ground wire ice melting. The parallel gap distance and segmented insulation length of ground wire are the key parameters affecting its normal operation and successful ice melting. The electrostatic and electromagnetic induction voltage of insulated OPGW under different lengths and tower types and different transposition modes of conductor and ground wire are analyzed. It is suggested that the insulated ground wire should be grounded at least one point. The relationship between the discharge voltage U50 % and the withstand voltage Uw required by the ground wire insulator and its gap under the ice melting condition is proposed. The gap distance value of the ground wire insulator in different ice areas is given, and it is pointed out that the gap distance meets the requirements of lightning protection and single-phase ground fault. The research results can provide technical basis for energy efficiency improvement, ice melting and safe operation of overhead ground wire.