TY - CHAP A1 - Kern, Alexander A1 - Imani Vashiani, Anahita A1 - Timmermanns, Tobias T1 - 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 T2 - 35th International Conference on Lightning Protection (ICLP) and XVI International Symposium on Lightning Protection (SIPDA) N2 - 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 façades 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 façade is used the threat for human beings touching is usually very low, if the façade is sufficiently interconnected and multiply connected to the lightning equipotential bonding or the earth termination system, resp. KW - Lightning protection system KW - down-conductor KW - steel columns KW - metal façade KW - touch voltage Y1 - 2021 SN - 978-1-6654-2346-5 U6 - http://dx.doi.org/10.1109/ICLPandSIPDA54065.2021.9627465 N1 - 35th International Conference on Lightning Protection (ICLP) and XVI International Symposium on Lightning Protection (SIPDA), 20-26 Sept. 2021, Colombo, Sri Lanka PB - IEEE ER - TY - CHAP A1 - Lo Piparo, G. B. A1 - Kern, Alexander A1 - Mazzetti, C. T1 - Some masterpoints about risk due to lightning T2 - International Conference on Lightning Protection (ICLP) : 2 - 7 Sept. 2012, Vienna Y1 - 2012 SN - 978-1-4673-1896-9 (E-Book) ; 978-1-4673-1898-3 (Print) SP - 1 EP - 6 PB - IEEE CY - Piscataway, NJ ER - TY - CHAP A1 - Kern, Alexander A1 - Braun, Christian T1 - Risk management according to IEC 62305-2 edition 2: 2010–12 assessment of structures with a risk of explosion T2 - 2014 International Conference on Lightning Protection (ICLP), Shanghai, China N2 - Risk management for structures with a risk of explosion should be considered very carefully when performing a risk analysis according to IEC 62305-2. In contrast to the 2006 edition of the standard, the 2010 edition describes the topic “Structures with a risk of explosion” in more detail. Moreover, in Germany separate procedures and parameters are defined for the risk analysis of structures with a risk of explosion (Supplement 3 of the German DIN EN 62305-2 standard). This paper describes the contents and the relevant calculations of this Supplement 3, together with a numerical example. Y1 - 2014 SP - 1237 EP - 1242 ER - TY - CHAP A1 - Kern, Alexander A1 - Dikta, Gerhard T1 - Probability of damage of electrical and electronic systems due to indirect lightning flashes - investigation of data from German insurance companies N2 - In the presented paper data collected from the field related to damage statistics of electrical and electronic apparatus in household are reported and investigated. These damages (total number approx. 74000 cases), registered by five German insurance companies in 2005 and 2006, were adviced by customers as caused by lightning overvoltages. With the use of stochastical methods it is possible, to reasses the collected data and to distinguish between cases, which are with high probability caused by lightning overvoltages, and those, which are not. If there was an indication for a direct strike, this case was excluded, so the focus was only on indirect lightning flashes, i.e. only flashes to ground near the structure and flashes to or nearby an incoming service line were investigated. The data from the field contain the location of damaged apparatus (residence of the policy holder) and the distances of the nearest cloud-to-ground stroke to the location of the damage registered by the German lightning location network BLIDS at the date of damage. The statistical data along with some complementary numerical simulations allow to verify the correspondence of the Standards rules used for IEC 62305-2 with the field data and to define some correction needs. The results could lead to a better understanding whether a damage reported to an insurance company is really caused by indirect lightning, or not. KW - Blitzschutz KW - lightning flash Y1 - 2009 ER - TY - CHAP A1 - Wetter, Martin A1 - Kern, Alexander T1 - Number of lightning strikes to tall structures - comparison of calculations and measurements using a modern lightning monitoring system T2 - 2014 International Conference on Lightning Protection (ICLP), Shanghai, China Y1 - 2014 SP - 1 EP - 7 ER - TY - CHAP A1 - Zischank, Wolfgang J. A1 - Heidler, Fridolin A1 - Wiesinger, J. A1 - Stimper, K. A1 - Kern, Alexander A1 - Seevers, M. T1 - Magnetic Fields and Induced Voltages inside LPZ 1 Measured at a 1:6 Scale Model Building N2 - Laborexperimente zu Blitzschutzzonen in Stahlbetongebäuden anhand eines Modells im Maßstab 1:6 N2 - For the application of the concept of Lightning Protection Zones (LPZ), the knowledge of the magnetic fields and induced voltages inside a structure is necessary. Laboratory experiments have been conducted at a downscaled model of a building (scale factor 1:6) to determine these electromagnetic quantities in case of a direct strike to the structure. The model (3 m x 2 m x 2 m) represented a small industrial building using the reinforcement of the concrete as electromagnetic shield. The magnetic fields and magnetic field derivatives were measured at several location inside the scaled model. Further, the voltages induced on three typical cable routes inside the model was determined. The influence of the lightning current waveshape, point-of-strike, bonding of the cable routes, and bridging of an expansion joint in the middle of the building on these quantities was studied. KW - Blitzschlag KW - Elektromagnetischer Schutzschild KW - Stahlbeton KW - Maßstabsgetreues Modell KW - Lightning KW - electromagnetic shielding KW - reinforced concrete KW - scaled model Y1 - 2004 ER - TY - CHAP A1 - Kern, Alexander A1 - Heidler, Fridolin A1 - Seevers, M. A1 - Zischank, Wolfgang J. T1 - 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 N2 - 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. N2 - Auswirkungen eines direkten Blitzeinschlages auf ein Gebäude, Vergleich von experimentellen Ergebnissen und Berechnungen basierend auf einer Formel aus der IEC 62305-4 KW - Blitz KW - Direkter Blitzschlag KW - Elektromagnetischer Schutzschild KW - Magnetische Felder KW - Induzierte Spannungen KW - Kalkulation KW - Direct lightning strike KW - electromagnetic shield KW - magnetic fields KW - induced voltages KW - calculations Y1 - 2004 SN - 0304-3886 N1 - Journal of electrostatics: Beitr. auf S. 379 - 385. doi:10.1016/j.elstat.2006.09.004 ER - TY - CHAP A1 - Kern, Alexander A1 - Krichel, Frank A1 - Müller, Klaus-Peter T1 - Lightning protection design of a renewable energy hybrid-system without power mains connection N2 - In the year 2000 a direct lightning strike to the hybridsystem without power mains connection VATALI on the Greek island Crete results in the destruction and damage of some mechanical and electrical components. The hybrid-system VATALI was not lightning protected at that time. The hardware damage costs are approx. 60,000 €. The exposed site of the hybrid-system on top of a mountain was and still is the reason for a high risk of lightning strikes. Also in the future further lightning strikes have to be taken into consideration. In the paper a fundamental lightning protection design concept for renewable energy hybrid-systems without power mains connection and protection measures against direct strikes and overvoltages are shown in detail. The design concept was realized exemplarily for the hybrid-system VATALI. 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. Future extensions, new installations, or modifications have to be included into the lightning protection design concept of the hybrid-system. KW - Blitzschutz KW - Erneuerbare Energien KW - Hybridsystem KW - Lightning protection KW - Renewable energy KW - hybrid-system Y1 - 2001 ER - TY - CHAP A1 - Zischank, Wolfgang J. A1 - Heidler, Fridolin A1 - Kern, Alexander A1 - Metwally, I. A. A1 - Wiesinger, J. A1 - Seevers, M. T1 - Laboratory simulation of direct lightning strokes to a modelled building - measurement of magnetic fields and induced voltages N2 - 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. KW - Direkter Blitzschlag KW - Elektromagnetischer Schutzschild KW - Magnetische Felder KW - Induzierte Spannungen KW - Stahlbetonkonstruktion KW - Lightning KW - electromagnetic shielding KW - magnetic field KW - reinforced concrete KW - induced voltage Y1 - 2002 ER - TY - CHAP A1 - Rousseau, Alain A1 - Kern, Alexander T1 - How to deal with environmental risk in IEC 62305-2 T2 - 2014 International Conference on Lightning Protection (ICLP), Shanghai, China N2 - The 2nd edition of the lightning risk management standard (IEC 62305-2) considers structures, which may endanger environment. In these cases, the loss is not limited to the structure itself, which is valid for usual structures. In the past (Edition 1) this danger was simply taken into account by a special hazard factor, multiplying the existing risk for the structure with a number. Now, in the edition 2, we add to the risk for the structure itself a “second risk” due to the losses outside the structure. The losses outside can be treated independently from what occurs inside. This is a major advantage to analyze the risk for sensitive structures, like chemical plants, nuclear plants, or structures containing explosives, etc. In this paper, the existing procedure given by the European version EN 62305-2 Ed.2 is further developed and applied to a few structures. Y1 - 2014 SP - 521 EP - 527 ER -