Study on Overhead Ground Wire Induced Voltage of 500kV AC/DC Transmission Lines for Ice Melting

Abstract

The method of insulating all the ground wires that need to be ice melted and adding DC power supply to ground wire is put forward for the overhead ground wire ice melting. In order to reduce the ground wire induced voltage, the overhead ground wire induced voltage of 500kV AC and ±500kV DC transmission lines with different operation modes is studied according to different tower types, ground wire models, line length and transposition, the limiting measures are put forward.500kV AC transmission lines with full transposition can effectively reduce the ground wire electrostatic induced voltage based on the conclusions. The ground wire with double circuits on the same tower needs to be grounded in sections to eliminate the electrostatic induced voltage. he more higher proportion of single circuit line to the whole line, the induced voltage of single and double curcuit hybrid lines is more smaller. hen the ground wire is insulated and no grounding point, the induced voltage increased with the increasing of line length and the single pole operation mode is greater than the double poles. As long as one point of ±500kV DC ground wire is grounded, the electrostatic induced voltage is greatly reduced.