Calculation Of Electric Field Intensity Of UHV AC Transmission Lines And Corona Effect Study

The economy of china is developing rapidly,the construction of UHV transmission lines is the key to economic development.With the increase of voltage level,the electric field intensity under the line is also increasing,which will affect the normal life of the surrounding residents.In order to control the electric field intensity under the transmission line,it is necessary to analyze and calculate the electric field intensity.In this paper,the finite element method(FEM)is used to study the distribution of electric field and its influencing factors.The actual UHV transmission line is taken as an example,using finite element software ANSYS to simulate and calculate the electric field intensity distribution at 1.5m below the transmission line,and calculate the change trend of electric field under different influencing factors.The simulation results show that the arrangement of the transmission line,the wires height from the ground,the distance between the phase conductors,the number of the sub-conductors and the terrain situation have a great influence on the electric field and corridor width at 1.5m below the line,and the sub-conductor radius has a smaller effect on the electric field below the line.Then,according to the influencing factors of the electric field under the transmission line,established the transmission line model under the optimized parameters is and calculate the electric field under the transmission line of the model.For some important areas,the requirements of the electric field limit are adopted,The two kinds of ways are used to suppress the electric field under the line,and the influence of different shielding parameters on the shielding effect is analyzed.The model of 1000kV and 500kV hybrid transmission lines is established.The electric field is compared with the 1000kV transmission line.:Reasonable setting of shielded wire parameters can control the electric field below the transmission line within the limit,and the transmission line mixing erection on the line below the electric field strength has a better shielding effect,from the electromagnetic environment,saving transmission corridor,increase the capacity per unit area,Increase the economy and other considerations,mixed with erecting relative to a single voltage erection has a great advantage.Finally,the causes of corona and its main influence are introduced.The audible noise,corona loss and radio disturbance are calculated.The main influencing factors of corona are the surface electric field and the halo The electric field is used to calculate the electric field on the surface of the transmission line,and the variation trend of the electric field intensity on the surface of the transmission line under different phase conductor parameters and sub-conductor parameters is studied.The results show that the number of sub-wire splitting has a great influence on the surface electric field,Spacing,height and so on.The formula of calculating the surface condition,weather condition and air humidity and density of the transmission line have certain influence on the corona process by formula and principle.