Analysis of tower surge impedance using the finite element method

摘要

In this work, the finite element method (FEM) provided computer generated results from electromagnetic fields, based on a 3D model of a transmission tower. The simulation of electric and magnetic fields enabled the calculation of the tower surge impedance. The surge impedance calculated from these results, uses traditional electromagnetism equations. Comparisons with measurements in a real tower allow for the validation of the proposed method, which resulted in surge impedance values with differences less than 0.5% in relation to the measurements. Additionally, the surge impedance from the proposed methodology is compared to results from analytical techniques, which resulted in differences of up to 60% in the values of surge impedance, in relation to the measurements. In order to verify the influence of tower surge impedance on tower voltages, a transmission tower was modeled using EMTP software. Under the influence of a surge current, the simulations provided tower voltages at strategic heights. Measurements of tower voltages made the comparison of these results possible in order to evaluate the consistency and accuracy of the tower model. (C) 2017 Elsevier B.V. All rights reserved.