@inproceedings{DarvenizaFlisowskiKernetal.2002, author = {Darveniza, M. and Flisowski, Z. and Kern, Alexander and Landers, E.-U. and LoPiparo, G. and Mazzetti, C. and Rousseau, A. and Sherlock, J.}, title = {Application problems of the probabilistic approach to the assessment of risk for structures and services}, year = {2002}, abstract = {The paper deals with the development of the probabilistic approach to the assessment of risk due to lightning. Sources of damage, types of damage and types of loss are defined and, accordingly, the procedure for risk analysis and the way of assessment of different risk components is proposed. The way to evaluate the influence of different protection measures (lightning protection system; shielding of structure, cables and equipment; routing of internal wiring; surge protective device) in reducing such probabilities is considered. The paper has been prepared within the framework of the activity of IEC TC81-WG9/CLC TC81-WG4 directed to prepare the draft IEC 62305-2 Risk Management, in cooperation with the Secretary of IEC/CLC TC81.}, language = {en} } @inproceedings{KernKrichel2002, author = {Kern, Alexander and Krichel, Frank}, title = {Considerations about the lightning protection system of mains independent renewable energy hybrid-systems - practical experiences}, year = {2002}, abstract = {In the paper a lightning protection design concept for renewable energy hybrid-systems without power mains connection is described. Based on a risk analysis protection measures against direct strikes and overvoltages are shown in an overview. The design concept is realized exemplarily for the hybrid-system VATALI on the Greek island Crete. VATALI, not lightning protected at that time, was a victim of a lightning strike in the year 2000 causing destructions and damages of some mechanical and electrical components with costs of approx. 60.000 €. The hardware costs for the protection measures were about 15.000 €: about 50\% of the costs are due to protection measures against direct strikes, 50\% are due to overvoltage protection.}, language = {en} } @inproceedings{ZischankHeidlerKernetal.2002, author = {Zischank, Wolfgang J. and Heidler, Fridolin and Kern, Alexander and Metwally, I. A. and Wiesinger, J. and Seevers, M.}, title = {Laboratory simulation of direct lightning strokes to a modelled building - measurement of magnetic fields and induced voltages}, year = {2002}, abstract = {In IEC 61312-2 equations for the assessment of the magnetic fields inside structures due to a direct lightning strike are given. These equations are based on computer simulations for shields consisting of a single-layer steel grid of a given mesh width. Real constructions, however, contain at least two layers of reinforcement steel grids. The objective of this study was to experimentally determine the additional shielding effectiveness of a second reinforcement layer compared to a single-layer grid. To this end, simulated structures were set up in the high current laboratory. The structures consisted of cubic cages of 2 m side length with one or with two reinforcement grids, respectively. The structures were exposed to direct lightning currents representing the variety of anticipated lightning current waveforms. The magnetic fields and their derivatives at several positions inside the structure as well as the voltage between "floor" and "roof" in the center were determined for different current injection points. From these data the improvement of the shielding caused by a second reinforcement layer is derived.}, language = {en} } @article{Kern2016, author = {Kern, Alexander}, title = {Blitz- und {\"U}berspannungsschutz von Kernkraftwerken - Nachweisf{\"u}hrung der ausreichenden Sicherheit f{\"u}r leittechnische Einrichtungen auch bei Blitzeinschl{\"a}gen mit extremen Parametern}, series = {Atw. International Journal for Nuclear Power}, volume = {61}, journal = {Atw. International Journal for Nuclear Power}, number = {8/9}, publisher = {Inforum}, address = {Berlin}, issn = {1431-5254}, pages = {534 -- 543}, year = {2016}, abstract = {F{\"u}r das Auftreten extremer Wetterereignisse werden f{\"u}r Kernkraftwerke Eintrittsh{\"a}ufigkeiten f{\"u}r nicht mehr beherrschbare Zust{\"a}nde von unter 10⁻⁴/a gefordert. Dies gilt auch f{\"u}r die Einwirkung von Blitzeinschl{\"a}gen. Die bisherige Nachweisf{\"u}hrung zu Blitz- und {\"U}berspannungsschutz eines KKW in Deutschland ist deterministisch. In diesem Bericht werden das Vorgehen f{\"u}r einen entsprechenden Nachweis f{\"u}r leittechnische Einrichtungen der Sicherheitstechnik von KKW, der zur geforderten Zielgr{\"o}ße der Eintrittsh{\"a}ufigkeit f{\"u}hrt. Die Ergebnisse werden zusammenfassend bewertet.}, language = {de} } @inproceedings{BirklDiendorferKernetal.2018, author = {Birkl, Josef and Diendorfer, Gerhard and Kern, Alexander and Thern, Stephan}, title = {Extremely high lightning peak currents}, series = {34th International Conference on Ligntning Protection, 02-07 September 2018}, booktitle = {34th International Conference on Ligntning Protection, 02-07 September 2018}, isbn = {978-1-5386-6635-7}, pages = {7 Seiten}, year = {2018}, language = {en} } @inproceedings{Kern2017, author = {Kern, Alexander}, title = {Optimierung des Blitzschutzes bei Biogasanlagen}, series = {12. VDE/ABB-Blitzschutztagung : Beitr{\"a}ge der 12. VDE/ABB-Fachtagung, 12.-13. Oktober 2017, Aschaffenburg}, booktitle = {12. VDE/ABB-Blitzschutztagung : Beitr{\"a}ge der 12. VDE/ABB-Fachtagung, 12.-13. Oktober 2017, Aschaffenburg}, isbn = {978-3-8007-4459-6}, pages = {48 -- 56}, year = {2017}, language = {de} } @inproceedings{KernBrocke2017, author = {Kern, Alexander and Brocke, Ralph}, title = {Planung von Fangeinrichtungen mit dem dynamischen elektro-geometrischen Modell - M{\"o}gliche praktische Anwendungen}, series = {12. VDE/ABB-Blitzschutztagung : Beitr{\"a}ge der 12. VDE/ABB-Fachtagung, 12.-13. Oktober 2017, Aschaffenburg}, booktitle = {12. VDE/ABB-Blitzschutztagung : Beitr{\"a}ge der 12. VDE/ABB-Fachtagung, 12.-13. Oktober 2017, Aschaffenburg}, isbn = {978-3-8007-4459-6}, pages = {75 -- 82}, year = {2017}, language = {de} } @inproceedings{BirklDiendorferKernetal.2017, author = {Birkl, Josef and Diendorfer, Gerhard and Kern, Alexander and Thern, Stephan}, title = {Extrem hohe Blitzstr{\"o}me}, series = {12. VDE/ABB-Blitzschutztagung : Beitr{\"a}ge der 12. VDE/ABB-Fachtagung, 12.-13. Oktober 2017, Aschaffenburg}, booktitle = {12. VDE/ABB-Blitzschutztagung : Beitr{\"a}ge der 12. VDE/ABB-Fachtagung, 12.-13. Oktober 2017, Aschaffenburg}, isbn = {978-3-8007-4459-6}, pages = {146 -- 152}, year = {2017}, language = {de} } @article{BirklDiendorferKernetal.2018, author = {Birkl, Josef and Diendorfer, Gerhard and Kern, Alexander and Thern, Stephan}, title = {Extrem hohe Blitzstr{\"o}me}, series = {Elektropraktiker}, volume = {72}, journal = {Elektropraktiker}, number = {3}, publisher = {Huss Medien}, address = {Berlin}, pages = {217 -- 225}, year = {2018}, abstract = {Blitze sind nach wie vor eine enorme Schadensquelle f{\"u}r Personensch{\"a}den, Br{\"a}nde, mechanische Zerst{\"o}rungen und insbesondere auch {\"U}berspannungen. Das zeigen nicht zuletzt aktuelle Statistiken der Schadensversicherer. Immer wieder gibt es Meldungen {\"u}ber extrem hohe Blitzstr{\"o}me, die nat{\"u}rlich auch zu großen Sch{\"a}den und Zerst{\"o}rungen f{\"u}hren k{\"o}nnen. Dabei werden Scheitelwerte von teilweise deutlich {\"u}ber 300 kA genannt. Dies wirft Fragen auf, da die „klassische" Blitzstatistik (z. B. nach CIGRE und IEC [8][10]) bisher solche Werte nicht kennt. Diese extremen Blitzstr{\"o}me werden meist aus den Daten von Blitzortungssystemen ermittelt.}, language = {de} } @inproceedings{KernImaniVashianiTimmermanns2021, author = {Kern, Alexander and Imani Vashiani, Anahita and Timmermanns, Tobias}, title = {Threat for human beings due to touch voltages and body currents caused by direct lightning strikes in case of non-isolated lightning protection systems using natural components}, series = {35th International Conference on Lightning Protection (ICLP) and XVI International Symposium on Lightning Protection (SIPDA)}, booktitle = {35th International Conference on Lightning Protection (ICLP) and XVI International Symposium on Lightning Protection (SIPDA)}, publisher = {IEEE}, isbn = {978-1-6654-2346-5}, doi = {10.1109/ICLPandSIPDA54065.2021.9627465}, pages = {8 Seiten}, year = {2021}, abstract = {For typical cases of non-isolated lightning protection systems (LPS) the impulse currents are investigated which may flow through a human body directly touching a structural part of the LPS. Based on a basic LPS model with conventional down-conductors especially the cases of external and internal steel columns and metal fa{\c{c}}ades are considered and compared. Numerical simulations of the line quantities voltages and currents in the time domain are performed with an equivalent circuit of the entire LPS. As a result it can be stated that by increasing the number of conventional down-conductors and external steel columns the threat for a human being can indeed be reduced, but not down to an acceptable limit. In case of internal steel columns used as natural down-conductors the threat can be reduced sufficiently, depending on the low-resistive connection of the steel columns to the lightning equipotential bonding or the earth termination system, resp. If a metal fa{\c{c}}ade is used the threat for human beings touching is usually very low, if the fa{\c{c}}ade is sufficiently interconnected and multiply connected to the lightning equipotential bonding or the earth termination system, resp.}, language = {en} }