Radio Interference And Electric Induction Of Human Body Under Parallel AC Transmission Line In Same Corridor

EHV/UHV power grid develops very quickly because it has played an important role in optimal allocation of energy, reducing loss and saving land resources. With the increase of transmission line, construction of parallel multi-circuit transmission lines in same corridor starts to become a trend, which leading to further deteriorate of electromagnetic environment. In recent years, the effect of UHV transmission lines on environment and the human body is concerned. Analysis focused on radio interference, human induced electric field and current density in order to clarifying these electromagnetic environmental problems.Firstly, the excitation function under heavy rain, light rain and the good weather which is corrected strictly is applied to computing radio interference of EHV AC multi-circuit transmission line in same corridor. The calculation results of radio interference under transmission line using this method are compared with the values of reference and calculation of empirical prediction formulae,certificating the validity of the algorithm. In order to reducing radio interference level of EHV AC transmission line in same corridor, the impact of radio interference produced by transmission line height and phase sequence is analyzed. On this basis, the best phase sequence of three-circuit transmission lines are discovered. The conclusion can be used to practical constructions.Secondly, the algorithm consist of CSM(Charge Simulation Method) and FEM(Finite Element Method) is proposed to study induced electrical field of human body. A realistic model of human body is established refer to literature of human body dimensions. Region of the finite element is determined by analysis of truncation error. Then the potential of boundary, the boundary conditions of FEM, is computed by CSM. The external and internal electric field strength and induced current densities of human body is computed by Finite element software ANSYS. The result shows that electric field strength increases strongly with the presence of the human body under 500 kV overhead transmission line and the value of current density is below limits set by ICNIRP guideline.Finally, the factors which affect human induced electric field and current density are discussed under two-circuit transmission line in same corridor. The results show that induced electric field and current density are largest when human body locates on the outside phase of the transmission line; increasing line height and same phase sequence can significantly reducing induced electric field and current density, while decreasing the phase spacing has a very small effect.