@inproceedings{ZischankKernFrentzeletal.2000, author = {Zischank, Wolfgang J. and Kern, Alexander and Frentzel, Ralf and Heidler, Fridolin and Seevers, M.}, title = {Assessment of the lightning transient coupling to control cables interconnecting structures in large industrial facilities and power plants}, year = {2000}, abstract = {Large industrial facilities and power plants often require a huge number fo information and control cables between the differnet structures. These I\&C-cables can be routed in reinforced concrete cable ducts or in isolated buried cable runs. KTA 2206 is the German lightning protection standard for nuclear power plants. During the last several years considerable effort has been made to revise this standard. Despite the well established principles and design guidelines for the construction of the lightning protection system, this standard puts special emphasis on the coupling of transient overvoltages to I\&C-cables.}, language = {en} } @inproceedings{SurteesGillespieKernetal.2004, author = {Surtees, A. J. and Gillespie, A. and Kern, Alexander and Rousseau, A.}, title = {DEVELOPMENT OF A RISK ASSESSMENT CALCULATOR BASED ON A SIMPLIFIED FORM OF THE IEC 62305-2 STANDARD ON LIGHTNING PROTECTION}, year = {2004}, abstract = {Neue Blitzschutznorm IEC 62305. Entwicklung einer einfachen Software zur Risikoabw{\"a}gung}, language = {en} } @inproceedings{KernHeidlerSeeversetal.2004, author = {Kern, Alexander and Heidler, Fridolin and Seevers, M. and Zischank, Wolfgang J.}, title = {Magnetic Fields and Induced Voltages in case of a Direct Strike - Comparison of Results obtained from Measurements at a Scaled Building to those of IEC 62305-4}, isbn = {0304-3886}, year = {2004}, abstract = {In the paper the results obtained from experiments at a modelled reinforced building in case of a direct lightning strike are compared with calculations. The comparison includes peak values of the magnetic field Hmax, its derivative (dH/dt)max and of induced voltages umax in typical cable routings. The experiments are performed at a 1:6 scaled building and the results are extrapolated using the similarity relations theory. The calculations are based on the approximate formulae given in IEC 62305-4 and have to be supplemented by a rough estimation of the additional shielding effect of a second reinforcement layer. The comparison shows, that the measured peak values of the magnetic field and its derivative are mostly lower than the calculated. The induced voltages are in good agreement. Hence, calculations of the induced voltages based on IEC 62305-4 are a good method for lightning protection studies of buildings, where the reinforcement is used as a grid-like electromagnetic shield.}, subject = {Blitz}, language = {en} } @inproceedings{ZischankHeidlerWiesingeretal.2004, author = {Zischank, Wolfgang J. and Heidler, Fridolin and Wiesinger, J. and Stimper, K. and Kern, Alexander and Seevers, M.}, title = {Magnetic Fields and Induced Voltages inside LPZ 1 Measured at a 1:6 Scale Model Building}, year = {2004}, abstract = {Laborexperimente zu Blitzschutzzonen in Stahlbetongeb{\"a}uden anhand eines Modells im Maßstab 1:6}, language = {en} } @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} } @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{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} }