IMPACT EVALUATION OF DIRECT LIGHTNING STRIKE ON A TOWER. GROUND POTENTIAL RISE ALTERNATIVE COMPUTATIONS

Autor/autori: Dr. Andrei CECLAN, Prof. Dr. Eng. Vasile TOPA , Assoc. Prof. Dr. Eng. Dan Doru MICU, PhD. Stud. Levente CZUMBIL

Rezumat: Orice structura metalica, in special cele inalte de telecomunicatii, turnuri eoliene sau alt tip de turnuri metalice pot servi ca si canale de descarcare pentru curenti de trasnet de ordinul sutelor de kA si astfel sa conduca la aparitia unor potentiale electrice periculoase la nivelul solului. In aceasta lucrare sunt descrise si evaluate caracteristicile principale ale campurilor electrice si magnetice generate in stratul superior al solului de diferite tipuri de curenti de trasnet care lovesc turnuri metalice. Problema a fost abordata utilizand o platforma de simulari numerice, pentru diferite scenarii - curenti de trasnet cu parametri diferiti, geometrii diferite de turnuri, rezistivitati diferite de sol, existenta sau nu a prizelor de impamantare - evaluandu-se tensiunea de pas si campul magnetic in zona din apropierea turnului lovit.

Cuvinte cheie: curent de intoarcere a trasnetului, tensiune de pas, turn metalic.

Abstract: Any metallic structure, especially tall ones like telecommunication, wind or other types of metallic towers can become a discharging channel for lightning currents (hundreds of kA) and therefore give rise to potential dangerous events on ground level. In this paper there are described and evaluated the main characteristics of the electric and magnetic fields produced in the upper soil layer by different types of lightning currents flowing through a tall metallic structure, a tower directly hit by lightning. The problem was addressed using the simulation environment of a software package. Simulations were performed for several scenarios, in order to reflect the influence of analyzed parameters (lightning current shape, tower geometry, soil resistivity and grounding system) over the ground potential rise, step voltages and magnetic fields in the area nearby the stroked tower.

Keywords: lightning return stroke current, step voltage, ground potential rise, metallic tower

DOWNLOAD PDF