Pub Date : 2012-11-12DOI: 10.1109/ICLP.2012.6344202
Alexander Kern, C. Schelthoff, Moritz Mathieu
Interception efficiency is the most important parameter to show the effectiveness of air-terminations. With the dynamic electro-geometrical model, a numerical method, it is possible to calculate such interception efficiencies. This model is based purely on internationally accepted models, parameters, and dependencies. So far it is used to calculate the interception efficiencies for rod-type air-terminations. An adaption of this model allows the calculation of interception efficiencies for mesh-type air-terminations. Up to now the effectiveness of this kind of air-terminations could only be shown on an “empirical base”. This gap could be closed now using the results of this paper.
{"title":"Calculation of interception efficiencies for mesh-type air-terminations according to IEC 62305-3 using a dynamic electro-geometrical model","authors":"Alexander Kern, C. Schelthoff, Moritz Mathieu","doi":"10.1109/ICLP.2012.6344202","DOIUrl":"https://doi.org/10.1109/ICLP.2012.6344202","url":null,"abstract":"Interception efficiency is the most important parameter to show the effectiveness of air-terminations. With the dynamic electro-geometrical model, a numerical method, it is possible to calculate such interception efficiencies. This model is based purely on internationally accepted models, parameters, and dependencies. So far it is used to calculate the interception efficiencies for rod-type air-terminations. An adaption of this model allows the calculation of interception efficiencies for mesh-type air-terminations. Up to now the effectiveness of this kind of air-terminations could only be shown on an “empirical base”. This gap could be closed now using the results of this paper.","PeriodicalId":400743,"journal":{"name":"2012 International Conference on Lightning Protection (ICLP)","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116644001","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-11-12DOI: 10.1109/ICLP.2012.6344365
Liliana Arevalo, V. Cooray
Electrostatic fields below the thundercloud lead to the formation of glow charge from grounded objects. The charge accumulated after certain time can initiate or inhibit the called streamer formation and consequently the inception and development of upward leaders. By means of a two dimensional numerical model that takes into account the particles behavior is observed that glow charge can smooth the electric field on top of the grounded rod and consequently hinder the inception of streamers and upward leaders from the grounded rod. It is concluded that to be able to initiate unstable upward leaders from the shielded grounded rod a sudden change of electric field is necessary. A two dimensional numerical model that solves the continuity equations for positive and negative ions and electrons coupled with Poisson equation was implemented. Comparison for different magnitudes of electric field and characteristics of rod are included as well.
{"title":"Corona charge produced by thundercloud fields in grounded rods","authors":"Liliana Arevalo, V. Cooray","doi":"10.1109/ICLP.2012.6344365","DOIUrl":"https://doi.org/10.1109/ICLP.2012.6344365","url":null,"abstract":"Electrostatic fields below the thundercloud lead to the formation of glow charge from grounded objects. The charge accumulated after certain time can initiate or inhibit the called streamer formation and consequently the inception and development of upward leaders. By means of a two dimensional numerical model that takes into account the particles behavior is observed that glow charge can smooth the electric field on top of the grounded rod and consequently hinder the inception of streamers and upward leaders from the grounded rod. It is concluded that to be able to initiate unstable upward leaders from the shielded grounded rod a sudden change of electric field is necessary. A two dimensional numerical model that solves the continuity equations for positive and negative ions and electrons coupled with Poisson equation was implemented. Comparison for different magnitudes of electric field and characteristics of rod are included as well.","PeriodicalId":400743,"journal":{"name":"2012 International Conference on Lightning Protection (ICLP)","volume":"99 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116174256","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-11-12DOI: 10.1109/ICLP.2012.6344382
A. Ceclan, V. Topa, A. Andreotti, D. Micu
Using direct measurements of lightning magnetic and electric field by inverse problem formulation it is performed the identification of the lightning return stroke current. The approach starts from Fredholm integral equations of the first kind as engineering models and uses modular regularization procedures based on a spatial and time dependent harmonic reconstruction of the lightning current. All the preliminary evaluations appear to be in good agreement with the actual characterization models for return stroke current of the lightning; moreover the precision as regarded to the effect is considerably improved.
{"title":"Regularization of ill-posed return stroke current identification problem","authors":"A. Ceclan, V. Topa, A. Andreotti, D. Micu","doi":"10.1109/ICLP.2012.6344382","DOIUrl":"https://doi.org/10.1109/ICLP.2012.6344382","url":null,"abstract":"Using direct measurements of lightning magnetic and electric field by inverse problem formulation it is performed the identification of the lightning return stroke current. The approach starts from Fredholm integral equations of the first kind as engineering models and uses modular regularization procedures based on a spatial and time dependent harmonic reconstruction of the lightning current. All the preliminary evaluations appear to be in good agreement with the actual characterization models for return stroke current of the lightning; moreover the precision as regarded to the effect is considerably improved.","PeriodicalId":400743,"journal":{"name":"2012 International Conference on Lightning Protection (ICLP)","volume":"350 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126681620","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-11-12DOI: 10.1109/ICLP.2012.6344224
J. Paulino, W. do Couto Boaventura, C. Barbosa
This paper presents a time-domain method for the calculation of induced voltages on an aerial wire above a soil represented by two horizontal layers. Each layer is assumed to be homogeneous, isotropic, and having its own electrical parameters: resistivity, permittivity and permeability. The horizontal electric field at the surface of the top layer is calculated for an incident azimuthal magnetic field and used for the calculation of the induced voltage, using a methodology previously presented by the authors. A simple line configuration is used in order calculate the voltages induced by typical return-stroke waveforms. The results show that the two layers influence the induced voltage waveform. For the example considered, the induced voltage is initially influenced by the first layer but, as time goes by, it follows the voltage that would be induced if the earth was homogeneous and had the characteristics of the second layer.
{"title":"Lightning induced voltage on an aerial wire above two-layer ground","authors":"J. Paulino, W. do Couto Boaventura, C. Barbosa","doi":"10.1109/ICLP.2012.6344224","DOIUrl":"https://doi.org/10.1109/ICLP.2012.6344224","url":null,"abstract":"This paper presents a time-domain method for the calculation of induced voltages on an aerial wire above a soil represented by two horizontal layers. Each layer is assumed to be homogeneous, isotropic, and having its own electrical parameters: resistivity, permittivity and permeability. The horizontal electric field at the surface of the top layer is calculated for an incident azimuthal magnetic field and used for the calculation of the induced voltage, using a methodology previously presented by the authors. A simple line configuration is used in order calculate the voltages induced by typical return-stroke waveforms. The results show that the two layers influence the induced voltage waveform. For the example considered, the induced voltage is initially influenced by the first layer but, as time goes by, it follows the voltage that would be induced if the earth was homogeneous and had the characteristics of the second layer.","PeriodicalId":400743,"journal":{"name":"2012 International Conference on Lightning Protection (ICLP)","volume":"69 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124441064","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-11-12DOI: 10.1109/ICLP.2012.6344383
N. Kokkinos, Nicholas Christofides, C. Charalambous
This paper aims to analyse the lightning protection system (LPS) of an isolated large and extended Photovoltaic (PV) installation park. The area where the PV plant operates is characterised by the high ground flash density (25 thunderstorm days per year) and the extremely high soil resistivity value (i.e. pure rock with a resistivity of more than 2000m). The paper includes the LPS system design after experimental testing results, which were performed in the laboratory. It also includes solutions to some difficult overcoming problems that were faced during the application of the lightning protection design.
{"title":"Lightning protection practice for large-extended photovoltaic installations","authors":"N. Kokkinos, Nicholas Christofides, C. Charalambous","doi":"10.1109/ICLP.2012.6344383","DOIUrl":"https://doi.org/10.1109/ICLP.2012.6344383","url":null,"abstract":"This paper aims to analyse the lightning protection system (LPS) of an isolated large and extended Photovoltaic (PV) installation park. The area where the PV plant operates is characterised by the high ground flash density (25 thunderstorm days per year) and the extremely high soil resistivity value (i.e. pure rock with a resistivity of more than 2000m). The paper includes the LPS system design after experimental testing results, which were performed in the laboratory. It also includes solutions to some difficult overcoming problems that were faced during the application of the lightning protection design.","PeriodicalId":400743,"journal":{"name":"2012 International Conference on Lightning Protection (ICLP)","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121981494","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-11-12DOI: 10.1109/ICLP.2012.6344215
B. Radičević, M. Savić, I. Badea
The impact of wind turbine blade rotation on the lightning behavior is not sufficiently studied. The theoretical analysis and experimental investigation, whose most important segments are described in this paper, should enable a better understanding of this phenomenon. The tests were conducted in the high-voltage laboratory, applying the up-and-down method for determination of the 50% flashover standard switching voltage. The impulse voltage waves were applied between the specially designed arching electrode and the blades of a reduced-size wind turbine model, driven by a frequency controlled motor. A lightning protection system in the form of receptors on the tips of the blades was examined. According to the theory of similarity the paper discusses the characteristics of direct atmospheric discharges for the several typical rotational speeds of the wind turbine. It was concluded that the number of direct lightning strikes in the zone of the air termination system on the blades is decreasing due to the rotation of the blades.
{"title":"Impact of wind turbine blade rotation on the lightning strike incidence","authors":"B. Radičević, M. Savić, I. Badea","doi":"10.1109/ICLP.2012.6344215","DOIUrl":"https://doi.org/10.1109/ICLP.2012.6344215","url":null,"abstract":"The impact of wind turbine blade rotation on the lightning behavior is not sufficiently studied. The theoretical analysis and experimental investigation, whose most important segments are described in this paper, should enable a better understanding of this phenomenon. The tests were conducted in the high-voltage laboratory, applying the up-and-down method for determination of the 50% flashover standard switching voltage. The impulse voltage waves were applied between the specially designed arching electrode and the blades of a reduced-size wind turbine model, driven by a frequency controlled motor. A lightning protection system in the form of receptors on the tips of the blades was examined. According to the theory of similarity the paper discusses the characteristics of direct atmospheric discharges for the several typical rotational speeds of the wind turbine. It was concluded that the number of direct lightning strikes in the zone of the air termination system on the blades is decreasing due to the rotation of the blades.","PeriodicalId":400743,"journal":{"name":"2012 International Conference on Lightning Protection (ICLP)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122171744","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-11-12DOI: 10.1109/ICLP.2012.6344309
A. N. Hansen, H. Erichsen, Z. Politis
This paper presents a new approach to evaluate the efficiency of surge protective devices (SPD) for the protection against lighting as applied on the electrical power systems of wind turbine generators (WTG). The parameters of the performance of the SPDs which are considered to be critical for this application are their lifetime and voltage protection level at the power input point of the equipment. In this paper a method is presented to determine the lifetime of a SPD component based on the estimation of its exposure to currents due to direct lightning on the WTG over its lifetime using a statistical analysis of the lightning currents that could strike on a WTG and a distribution analysis of the lightning current in the WTG's electrical and grounding system. A lifetime test procedure for SPDs is suggested followed by an experimental verification test. Moreover, the voltage protection level at the equipment power input point is considered and a test procedure is also proposed to measure the effective voltage protection level using several expected voltage and current waveforms. Experimental results are presented to demonstrate the dependence of the voltage protection level on the SPD technology, installation configuration and equipment input impedance. The same approach could also be used in other application areas of SPDs, provided that the corresponding test procedures are adapted to the specific requirements of each application.
{"title":"Lightning Protection of the Electrical Systems of WTG: Evaluation Considerations Related to the Application of SPDs","authors":"A. N. Hansen, H. Erichsen, Z. Politis","doi":"10.1109/ICLP.2012.6344309","DOIUrl":"https://doi.org/10.1109/ICLP.2012.6344309","url":null,"abstract":"This paper presents a new approach to evaluate the efficiency of surge protective devices (SPD) for the protection against lighting as applied on the electrical power systems of wind turbine generators (WTG). The parameters of the performance of the SPDs which are considered to be critical for this application are their lifetime and voltage protection level at the power input point of the equipment. In this paper a method is presented to determine the lifetime of a SPD component based on the estimation of its exposure to currents due to direct lightning on the WTG over its lifetime using a statistical analysis of the lightning currents that could strike on a WTG and a distribution analysis of the lightning current in the WTG's electrical and grounding system. A lifetime test procedure for SPDs is suggested followed by an experimental verification test. Moreover, the voltage protection level at the equipment power input point is considered and a test procedure is also proposed to measure the effective voltage protection level using several expected voltage and current waveforms. Experimental results are presented to demonstrate the dependence of the voltage protection level on the SPD technology, installation configuration and equipment input impedance. The same approach could also be used in other application areas of SPDs, provided that the corresponding test procedures are adapted to the specific requirements of each application.","PeriodicalId":400743,"journal":{"name":"2012 International Conference on Lightning Protection (ICLP)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129864396","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-11-12DOI: 10.1109/iclp.2012.6344392
L. Carvajal, B. Wibisono, E. Tenicela
This paper focuses on design practices for the effective placement of downconductors to increase the level of direct lightning strike protection of Airport Traffic Control Towers (ATCT) in the United States. The adopted design practice is based on the use of the voltage gradient model as applied to tall towers. A scheme of balanced placement of downconductors for ATCTs is presented along with a simplified PSpice simulation that indicates related performance improvements.
{"title":"Installation schemes for downconductors at Airport Traffic Control Towers (ATCT)","authors":"L. Carvajal, B. Wibisono, E. Tenicela","doi":"10.1109/iclp.2012.6344392","DOIUrl":"https://doi.org/10.1109/iclp.2012.6344392","url":null,"abstract":"This paper focuses on design practices for the effective placement of downconductors to increase the level of direct lightning strike protection of Airport Traffic Control Towers (ATCT) in the United States. The adopted design practice is based on the use of the voltage gradient model as applied to tall towers. A scheme of balanced placement of downconductors for ATCTs is presented along with a simplified PSpice simulation that indicates related performance improvements.","PeriodicalId":400743,"journal":{"name":"2012 International Conference on Lightning Protection (ICLP)","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131993096","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-11-12DOI: 10.1109/ICLP.2012.6344288
Mary Ann Cooper
Multiple reports have reviewed the medical aspects of lightning injury but they are primarily based on cases that are taken from developed countries [1-3]. Often, accounts in developing countries report much more severe injuries than usually occur in developed countries. Insufficient data exists to determine if these reports are exceptions or actually reflect a difference in injury pattern. This paper will examine potential reasons for bias in these reports as well as propose hypotheses that may account for any true differences in the injuries.
{"title":"Whether the medical aspects of lightning injury are different in developing countries","authors":"Mary Ann Cooper","doi":"10.1109/ICLP.2012.6344288","DOIUrl":"https://doi.org/10.1109/ICLP.2012.6344288","url":null,"abstract":"Multiple reports have reviewed the medical aspects of lightning injury but they are primarily based on cases that are taken from developed countries [1-3]. Often, accounts in developing countries report much more severe injuries than usually occur in developed countries. Insufficient data exists to determine if these reports are exceptions or actually reflect a difference in injury pattern. This paper will examine potential reasons for bias in these reports as well as propose hypotheses that may account for any true differences in the injuries.","PeriodicalId":400743,"journal":{"name":"2012 International Conference on Lightning Protection (ICLP)","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133415011","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-11-12DOI: 10.1109/ICLP.2012.6344329
F. D'alessandro
This paper describes two unprecedented experiments that will answer two of the most fundamental and outstanding questions that remain today regarding the lightning attachment process, namely: (1) Ultra-long, free-ranging sparks that replicate typical “sneak” lightning discharges are used to evaluate and quantify the interception efficiency of the most common LPS's used around the world, and (2) Lightning flash counters and high-speed video cameras are used to make optical observations of natural lightning strikes to a tall structure in order to measure the striking distance and to compare it with current and past models of the lightning attachment process. The quantified outcomes expected from the test campaigns are both profound and of great importance to lightning protection practice, particularly with respect to quantifying the effectiveness of air terminals and lightning protection systems.
{"title":"Two unprecedented experiments to evaluate the effectiveness of lightning protection systems","authors":"F. D'alessandro","doi":"10.1109/ICLP.2012.6344329","DOIUrl":"https://doi.org/10.1109/ICLP.2012.6344329","url":null,"abstract":"This paper describes two unprecedented experiments that will answer two of the most fundamental and outstanding questions that remain today regarding the lightning attachment process, namely: (1) Ultra-long, free-ranging sparks that replicate typical “sneak” lightning discharges are used to evaluate and quantify the interception efficiency of the most common LPS's used around the world, and (2) Lightning flash counters and high-speed video cameras are used to make optical observations of natural lightning strikes to a tall structure in order to measure the striking distance and to compare it with current and past models of the lightning attachment process. The quantified outcomes expected from the test campaigns are both profound and of great importance to lightning protection practice, particularly with respect to quantifying the effectiveness of air terminals and lightning protection systems.","PeriodicalId":400743,"journal":{"name":"2012 International Conference on Lightning Protection (ICLP)","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113965533","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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