TY - JOUR
T1 - Reduction of lightning-induced magnetic fields and voltages inside struck double-layer grid-like shields
AU - Metwally, Ibrahim A.
AU - Heidler, Fridolin H.
PY - 2008
Y1 - 2008
N2 - This paper presents a numerical analysis of the reduction of lightning-induced magnetic fields and voltages inside double-layer grid-like spatial shields typically used in reinforced concrete buildings, e.g., nuclear power plants. The calculations are performed with the CONCEPT computer code, which solves Maxwell's equations using the method of moments in the frequency domain. The computer code is extended with the well-known transmission line model (TL-model) in order to simulate direct lightning strikes. The structure under study comprises a cubic cage of 2 m side length having single- or double-layer grid-like spatial shields with square meshes of 0.25 m width. Three lightning-channel attachment points are considered at the cage roof, namely, the center, the midedge, and the corner. The simulated lightning currents are the positive, the negative first, and the negative subsequent strokes at lightning protection level I (LPL I) according to the international standard series IEC 62305. The computed quantities comprise the currents through some selected wires of the grid-like spatial shields, the magnetic fields, the magnetic-field derivatives, and the induced voltage across a typical installation loop inside the shield. The results of the single-layer shield are compared to those of the double-layer one to evaluate the additional reduction of the latter shield.
AB - This paper presents a numerical analysis of the reduction of lightning-induced magnetic fields and voltages inside double-layer grid-like spatial shields typically used in reinforced concrete buildings, e.g., nuclear power plants. The calculations are performed with the CONCEPT computer code, which solves Maxwell's equations using the method of moments in the frequency domain. The computer code is extended with the well-known transmission line model (TL-model) in order to simulate direct lightning strikes. The structure under study comprises a cubic cage of 2 m side length having single- or double-layer grid-like spatial shields with square meshes of 0.25 m width. Three lightning-channel attachment points are considered at the cage roof, namely, the center, the midedge, and the corner. The simulated lightning currents are the positive, the negative first, and the negative subsequent strokes at lightning protection level I (LPL I) according to the international standard series IEC 62305. The computed quantities comprise the currents through some selected wires of the grid-like spatial shields, the magnetic fields, the magnetic-field derivatives, and the induced voltage across a typical installation loop inside the shield. The results of the single-layer shield are compared to those of the double-layer one to evaluate the additional reduction of the latter shield.
KW - Direct strike
KW - Electromagnetic field
KW - Grid-like spatial shield
KW - Induced voltage
KW - Lightning current
KW - Reduction
KW - Reinforced buildings
KW - Transient analysis
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U2 - 10.1109/TEMC.2008.2002575
DO - 10.1109/TEMC.2008.2002575
M3 - Article
AN - SCOPUS:57049123684
SN - 0018-9375
VL - 50
SP - 905
EP - 912
JO - IEEE Transactions on Electromagnetic Compatibility
JF - IEEE Transactions on Electromagnetic Compatibility
IS - 4
ER -