Research On EHVAC Transmission Lines' Electromagnetic Field And EHVDC Transmission Lines' Total Electric Field

Since the first 500kV transmission line has been put into operation , EHV transmission line developed rapid and became the core network of our country power system. With the global economic development and people's increasing environment awareness ,the electromagnetic environmental problem caused by power transmission is paid more and more attention. Also the influence of the EHV transmission line to the around environment will become the mostly restricted factor in the development of EHV transmission system.This paper focus on the electromagnetism field distribution under the EHVAC transmission lines and the total electric field distribution under the EHV DC transmission lines.For the power frequency electromagnetic field distribution under the EHVAC transmission lines,the influence of the transmission line's parameters to the power frequency electromagnetic field distribution under the transmission lines is simulated in this paper,the results show that the height of conductor is the main factor. The power frequency electromagnetic field under the double-loop is also studied in the paper,the result shows that the opposite form of the double-loop can minish the power frequency electric field effectively,but no effect to the power frequency magnetic field. To reduce the electric field under the transmission lines, shield lines spaning under the transmission lines is simulated ,the result shows that this measurement will reduce electric field.The electric field distribution under the four-phase transmission lines is studied and compared with the three-phase's,the result shows that four-phase have advantage when considering power frequency electric field distribution.The total electric field distribution under of EHVDC transmission lines is simulated based on the method of Deutsch assumption. the influence of the transmission line's parameters to the total electric field distribution under the transmission lines is studied in this paper,the results show that the height of conductor is the main factor.