Calculation on the Total Electric Field Under ±800 kV Yun-Guang UHVDC Transmission Line

The total electric field above ground is special electric-magnetic environment phenomenon on HVDC transmission line.It is composed of two parts,one is the ion caused by corona of conductors,another is the electric field generated by voltage on conductors.This paper calculates the total electric field under 800kV Yun-Guang UHVDC transmission line with finite method. In calculation,7 different types of conductors(5 LGJ-630/45,5 LGJ-720/50,6 LGJ-500/35,6 LGJ-630/45,6 LGJ-720/50) is considered,and the least height of conductors above the ground is from 16m to 22m.The space between two pole conductors is 22m.The conclusion shows that the total electric field is determined by the types and height of conductors when the voltage and tower does not change on UHVDC transmission line,and it decreases with increscent section and high of conductors.It also shows that the total electric field under 800kV Yun-Guang UHVDC transmission line should be limited in 30kV/m,the conductor should use 5 LGJ-630/45 or larger section,and the least height of conductors above the ground should be higher than 18m.