Numerical methods to evaluate the electromagnetic fields below overhead transmission lines and their measurement

An increasing sensibility to ecological problems is seen. In the phase of planning high-voltage lines, the magnetic and electric field quantities have to be examined in order to avoid EMC problems with the surroundings of the power line. This request becomes even more important with the trend towards higher transmission line voltages. In this paper, the computation of the electric and magnetic field distribution below AC high-voltage lines is demonstrated. Advantages and disadvantages of two different methods able to evaluate the field quantities are described. The first discussed method, a semi numerical method using the laws of electrostatic techniques to simulate the three dimensional field distribution below the overhead line and second, the finite element method using specific boundary conditions to compute the two dimensional field distribution in an efficient way are under consideration. Results from both techniques are compared to measured data to verify the computed field values