In order to avoid tripping of line due to ice coating and not affect operation of line in the ice melting

the live ice melting system for ultra-high voltage line ground wire and optical fiber composite overhead ground wire (OPGW)

including ice melting power supply

ice melting device

over-voltage protection system

OPGW and ground wire circuit

is developed. The check of OPGW/ground wire melting parameter and melting device parameter

type selection of transformers

smoothing reactors

bridge arm over-voltage protectors and design of the insulation transformation and insulation coordination of melting ice lines are performed

and an OPGW live melting ice system for ultra-high voltage lines is developed. The actual measurement at site shows that

in case the both ends of the ice melting circuit are open

the induced voltage of OPGW/ground wire can reach 13.7 kV. When the single end of the ice melting circuit is grounded

the induced voltage decreases to 0.6 kV. The calculation shows that the selected rated parameters of 10 kV/10 MW for the live ice melting device can meet the ice melting requirements at site. The surface icing of OPGW/ground wire is irregular

and the growth of ice length

diameter

and thickness is a nonlinear process. The actual measurement at site shows that after the ice melting device outputs a 260 A DC current for 75 minutes

the maximum temperature of OPGW rises to 20.7 ℃

completing safely the live ice melting of ultra-high voltage lines. The live ice melting system for OPGW of ultra-high voltage transmission lines developed in the paper provides a guarantee for safe operation of ultra-high voltage DC lines in rainy

snowy

and freezing weather.