Lightning protection, earthing and surge protection of base transmission stations
An effective lightning protection design for a telecommunication facility requires an integrated approach to a number of key factors: • Protection against direct lightning strikes • Effective earth termination network for discharge of lightning current • Integration of power supply and lightning protection earthing systems • Extensive equipotential bonding to prevent electric shock • Mitigation for ground potential rise • Prevention of conducted surges to equipment cabin • Mitigation of LEMP This paper examines the challenges and solutions in the integration of lightning protection, earthing and surge protection for a base transmission station comprising a telecom tower and an equipment cabin, taking into consideration external power source via overhead lines.
Estimation of Actual Earth Resistance in Complex Earthing Networks: A Case Study for Telecom Towers
In this paper, we address the problem of estimating the actual earth resistance of a complex earthing system. Specifically, we model the earthing network using ANSYS Electromagnetics in the finite element domain. Then, we compare the theoretical and simulated results to estimate the earth resistance by analyzing the relationship between them. Finally, we validate the effectiveness of the proposed method using simulation and experimental results.
Geomagnetic micropulsations due to the motion of ocean waves
When sea waves move in the magnetic field of the earth, electric currents are generated in the water volume. These currents give rise to a small magnetic field which perturbs the earth's field. For plane trochoidal waves, this perturbing field decays exponentially with altitude and lies in a vertical plane which is oriented in the direction of wave propagation. The magnitude of the perturbing field also depends upon the magnitude and dip angle of the earth's field, and upon the height, wavelength, and propagation direction of the sea waves. For north-south waves, sea state 5, and an altitude of 100 feet, the perturbation is of the order of 0.1 gamma.