Study On Simulation Of Electromagnetic Fields Caused By Extra High Voltage Transmission Lines

With the development of electric power industry and many towns rapidly expanding, 220kV transmission lines often occur and cross the towns, inevitably do 500kV transmission lines which originally cross the suburbs and mountainous areas. It would bring harm to environment because power-frequency electromagnetic field exists around the super high voltage transmission lines. It is noticeable that electromagnetic pollution disturbs the people right in these areas.To simulate the power-frequency electromagnetic field induced by super high voltage transmission lines, Charge Simulation Method, Current Simulation Method and Method of Moment are chose. The spirit, steps of CSM and styles of charges are introduced based of Equivalent Theory. The spirit and steps of CUSM are also introduced. The structure and usage of MOM are described.To more easily simulate, some assumptions about transmission lines are made. The mathematic model about two-dimension-electric field of super high voltage transmission lines is established. It's adapted to open, flat areas and slope. Rules of power frequency electric field are summarized after examples. The model about super high voltage transmission lines with overhead ground wires is also established. The effect of overhead ground wires is analyzedThe super high voltage transmission lines are high current system. The distribution of currents on surface of the lines is asymmetric. Current Simulation Method is adopted. The mathematic model about two-dimension-magnetic field of super high voltage transmission lines is founded. Rules of power-frequency electric field are analyzed.To easily solve actual complex issues, combined method of CSM and MOM is brought forward based on point-matching method of and characteristic of scattering integral equations MOM.According to actual cases, corresponding quasi-three-dimension-electric models of finite lines, half-infinite lines, catenary lines are established.Arrangement, height and phase-order of transmission lines, overhead ground lines, slant, shield lines and so on, are mostly simulated. The distributing characteristic of electric field is summarized, in case of various cases associated with the criterion of environmental evaluation. At last, some advice and methods of eliminating electric field under the transmission lines entering the megalopolis is proposed, with regard toprotecting environment.