In this paper, a computationally efficient broadband electromagnetic simulation of lightning protection system is presented. The approach employs a hardware accelerated implementation of the method of moments combined with the Stoer-Bulirsch algorithm and adaptive frequency sampling scheme to explore the frequency response of a large volume grid-like structures directly hit by lightning. Emphasis is placed on the evaluation of the lightning-induced magnetic field intensity and its derivative within the volume protected by single- and double-layer shields.
Słowa kluczowe: lightning protection; magnetic field shielding; frequency-domain analysis; method of moments.
W referacie opisano efektywną obliczeniowo, opartą na metodzie momentów, technikę szerokopasmowej analizy dużych, ekranujących struktur siatkowych umożliwiających ochronę przed wyładowaniami atmosferycznymi. Skuteczność metody pokazano przy wyznaczaniu natężenia pól magnetycznych indukowanych w trakcie bezpośrednich wyładowań atmosferycznych w obszarach chronionych przez jedno- i dwuwarstwowe ekrany.
Keywords: ochrona odgromowa, ekranowanie pól magnetycznych, analiza w dziedzinie częstotliwości, metoda momentów
Lightning is a source of aggressive harmful highintensity electromagnetic (EM) effects usually referred to as Lightning Electromagnetic Pulse (LEMP). The energy of LEMP may be sufficient to cause damage to sensitive electronics in electrical and electronic systems within structures. Therefore, protection measures to reduce the risk of failure of internal systems due to LEMP are vitally important . This is particularly true for data processing, storage, and process control systems, radio systems, power electronic installations, telecommunication equipment, and similar. The principal source of potential damage is the lightning current and the associated magnetic field. This latter may be reduced to the acceptable level by employing magnetic shields. Large volume shields for protecting rooms and/or buildings are usually created by dedicated meshes of conductors combined with natural components of the structure such as the metal framework and the metal reinforcement in the walls, floors and ceilings. These elements taken together form three-dimensional grid-like spatial shields , and prediction of their response to lightning induced EM excitation is crucial for effective design of system protection (SPM) against LEMP. Perhaps the most suitable and accurate technique for EM analysis of grid-like shields composed of arbitrarily arranged conductors is the full-wave method of moments (MoM) formulated in the frequency domain (FD) . Unfortunately, the direct MoM is considered computationally inefficient when a broadband response of a structure is required, since EM simulation must be performed repeatedly at many discrete frequencies and the computational cost can be prohibitive for complex structures. In this paper, a computationally efficient CUDA-enabled heterogeneous CPU+GPU co-processing implementation of the method of moments is used for electromagnetic simulation of large volume grid-like spatial shields over a wide [...]
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