Analysis of influence factors of the total electric field distribution beneath UHVDC power lines

Total electric field should be considered during the design of UHVDC transmission lines as one of the principal environment indices. The upstream finite element method (UFEM) was applied to analyze the total ground electric field and ionic current density distributions under 800 kV UHVDC power lines. The effectiveness of the method was validated, and the Yunguang 800 kV UHVDC power lines were calculated to analyze the influences of the height, line spacing, conductor surface condition, and the polarity. The analysis results show that, increasing the height can reduce the total electric field obviously, but line spacing has little influence on the total electric field. The condition of the conductor surface should be considered to control the total ground electric field.