Statistical Analysis of Long-Term Measured Electric Field of the Operating ± 800kV HVDC Bipolar Transmission Lines

Presently, there is a lack of understanding regarding the distribution of the DC electric field of actual operating bipolar ±800kV lines and its statistical correlation with meteorological factors. A 13-month measurement has been conducted for the operating ±800kV HVDC bipolar transmission lines in China, from which the statistical variation of the DC electric field at the ground level were obtained across various seasons. It is found that electric field distribution is asymmetric except for summer and the average values of electric field statistics for all seasons are similar to those in autumn. The correlation between the meteorological parameters and the electric field was analyzed with correlation coefficients and Random Forests algorithm. And it indicates the wind speed perpendicular to lines, relative humidity and air pressure is the most influential meteorological parameters.