Research On The Electromagnetic Environment Of 1000 KV Ultra High Voltage Alternating Current Transmission Line

In order to utilize energy highly efficiently,form a structure of which the electricity is treated as the center of the power,and solve the more and more obvious problem of the need and distribution about energy,our country devotes major efforts to ultra high voltage projects.These can meet the increasing need of the social economy.The electromagnetic harm which is possibly produced by transmission equipments with extreme high voltage especially ultra high voltage causes people's attention and concern.Many scholars also have studied electromagnetic radiation which is caused by ultra high voltage transmission equipments.However,the selected ultra high voltage transmission towers and lines are inconsistent and onefold contrasting with the actual ultra high voltage alternating current projects.When the electromagnetic effect in human body produced by ultra high voltage transmission lines is considered,the model is comparatively simple.In most cases,the human body is regarded as a solution domain.Based on these,in this thesis,the changes of electromagnetic environment generated by the lines in ultra high voltage cat type towers and compact towers improved are studied,and then the safety is assessed.The thesis is based on the current 1000 kV ultra high voltage power transmission projects.The factors which can influence the power frequency electromagnetic field near ultra high voltage alternating current transmission line including height,phase spacing,the number of divisions,the wiring way,phase sequence of double loops and the line sag are analyzed.The distribution of power frequency electromagnetic field produced by the lines in 1000 kV ultra high voltage alternating current ZMP1 cat type transmission towers are compared with the one produced by the lines in 1000 kV ultra high voltage alternating current compact transmission towers.Many details of domestic and overseas authoritative journals about the size and electromagnetic parameters of human body are used as the references.Meanwhile the main parameters are verified.A closely actual human body model is built.The outdoor security of electromagnetism in the lines of the two tower models is evaluated.The spread laws of electric field intensity,current density and magnetic induction intensity in nearby air and human body including trunk,scalp,skull,brain and central nervous system in the head caused by the lines with actual sag and through the area of typical height hanging on the 1000 kV ultra high voltage alternating current ZMP1 cat type towers and compact towers in common weather of years are researched,then these simulation results are compared.As to the security of electromagnetic radiation,the values of electric field intensity,current density and magnetic induction intensity are compared to the occupational and general public limits of the ICNIRP guidelines.The safety assessment is judged,then suggestions of ultra high voltage alternating current electromagnetic protection are provided.The results show that,as to the present standard 1000 kV ultra high voltage alternating current transmission lines used in our country,the biggish values of the electric field intensity and current density produced by the lines mainly concentrate in the joints and legs.The electric field intensity,and magnetic induction intensity produced by the lines of 1000 kV ultra high voltage ZMP1 cat type transmission towers would not exceed the general public limits of ICNIRP guidelines.There is a risk that the current density in the legs and joints of human body overstep the general public limits of ICNIRP guidelines,but the current density would not exceed the occupational limits.The electric field intensity,current density and magnetic induction intensity in human body generated by the lines of 1000 k V ultra high voltage alternating current compact towers improved can be reduced significantly.The electromagnetic radiation of the lines hanging on 1000 kV ultra high voltage alternating current ZMP1 cat type towers and compact towers is safe to employees of power grid enterprise.But as to ordinary people who locate near the lines of 1000 kV ultra high voltage alternating current ZMP1 cat type towers,some measurements of electromagnetic protection in the joints and legs are supposed to be adopted.