This wire is also called shield or earth wire. It is connected to the steel tower body, and the steel tower is connected to the ground through the body resistance. It protects the phase from lightning, since it is the lowest voltage and it is at the highest point. Will not reach And then the electricity will go to the ground without causing excessive voltage problems on our transmission line.
Therefore, its main purpose is to protect from lightning. One thing to note is that this wire is only designed to carry current during high voltage conditions and has nothing to do with the neutral wire. In general, high voltage transmission networks have no neutral wires.