An Increase in line voltage increase the transmission effeciency . At voltages above 300KV [ Referred to as Extra High Voltages Or EHV ] . Corona causes a significat power loss and interference with communication circuits , If the circuit has one conductor per phase .
The use of multible conductors per phase decreases the voltage gardient in the vicinity of the line and thus reduce the possiblites of the corona discharge . Such an arrangemnet is Known as " Bundled counductor "
Inductance in " One Conductor " & " Bundled Conductor "
Question : Explain Why the Inductance of a bundled Conductor line is less than that of a similar line with one conductor per phase ?
Answer : Check the images in the left Corner