Simulation Research On Electromagnetic Environment Of Hefei Power Transmission And Transformation Project

With the development of Chinese social economy,the enlargement of city scale,electric power demand is increasing.But in our country,the promotion of energy supply capacity is restricted by "two imbalances ".One is the uneven distribution of energy resources,energy resources in central and eastern China is relatively scarce,while the west is very rich;The other is the uneven economic development in various regions,the eastern and central part of the economy is relatively developed,the demand for energy is larger,and the western economy is smaller,the demand for energy is relatively small.Because of this imbalance continues to promote the upgrading of the level of China’s power grid voltage,UHV,UHV power transmission projects continue to emerge.Along with the development of the power grid,the public is very concerned about the environment and health issues,the electromagnetic environment of the power transmission and transformation project is attracting more and more attention.Therefore,it is necessary to study the electromagnetic environment around high voltage lines and substations.The electromagnetic environment of power transmission and transformation project mainly includes four aspects: power frequency electric field,power frequency magnetic field,radio interference and audible noise.(1)Simulation of electromagnetic field around power transmission and transformation project.In this paper,the equivalent charge method is used to calculate the electric field intensity at different voltage levels,and the electromagnetic environment of UHV transmission line and a typical 500 k V substation is simulated.Some transmission lines and substations in Hefei are measured,and some rules of electromagnetic environment distribution are obtained.(2)Study on the distribution of power frequency electrical field under 500 k V AC overhead line.In this paper,the electric field under the two typical lines of500 k V is compared.The results show that the electric field intensity of the conventional tower is larger.On the basis of this,the distortion of electric field in the vicinity of the corridor is further studied,the maximum value of the electric field strength of the house appears at the edge of the wall near the conductor,usually at the top of the house and the edges of the balcony fence.In addition,based on the special housing(such as parapet houses,townhouses steeple houses,etc.)were studied.The conclusions can provide the reference for the house planning and construction near high voltage transmission line in the future.(3)Simulation study on the influence of gas condition on the distribution of power frequency electric field.According to the main meteorological data such astemperature,air pressure,humidity and other factors in Hefei,the influence of power frequency electric field is simulated and analyzed.It can be found that meteorological conditions have some influence on the distribution of power frequency electric field,but can be ignored.(4)Simulation research on electromagnetic field distribution of cable under pavement.It is found that the main factors that influence the magnetic field distribution of underground cable includes: the surface of different height,cable load,space position of cable(such as buried depth,distance,arrangement and sequence),laying methods.Through the simulation analysis of the 110 k V and 220 k V cables in the cable trench,it can be concluded that the level of the power frequency electromagnetic field of the underground cable is in line with the corresponding electromagnetic field safety threshold.