Pub Date : 2012-11-12DOI: 10.1109/ICLP.2012.6344267
L. Ruhnke
A qualitative model of a branched, positive upward leader is discussed that explains observations of the current cutoff of base current before the end of leader structure development and the fast recovery of nearby electric fields. Screening of cloud electric fields by branching is a powerful mechanism to influence branch cutoffs a well as the birth of recoil leaders on old dead channels. The analysis is based on well established physics principles of leader behavior in thunderstorms like the theory of Kasemir [2] on leader charge relation to environmental potential and [3] the formation of static charges by the streamer process.
{"title":"Screening effects on branched upward leaders","authors":"L. Ruhnke","doi":"10.1109/ICLP.2012.6344267","DOIUrl":"https://doi.org/10.1109/ICLP.2012.6344267","url":null,"abstract":"A qualitative model of a branched, positive upward leader is discussed that explains observations of the current cutoff of base current before the end of leader structure development and the fast recovery of nearby electric fields. Screening of cloud electric fields by branching is a powerful mechanism to influence branch cutoffs a well as the birth of recoil leaders on old dead channels. The analysis is based on well established physics principles of leader behavior in thunderstorms like the theory of Kasemir [2] on leader charge relation to environmental potential and [3] the formation of static charges by the streamer process.","PeriodicalId":400743,"journal":{"name":"2012 International Conference on Lightning Protection (ICLP)","volume":"32 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":"129292296","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.2012.6344335
Y. Naito
As a method for protecting electronic equipments from lightning attacks, mounting of SPD (surge protective device) which consists of a gas discharge tube (GDT), metal oxide varistor (MOV), and others is useful. In protecting equipment by SPD, overvoltage protection and energy harmonization become important. Above all, when overvoltage protection is thought of, response characteristics become important. Response characteristics depend on wavefront length and peak value applied to the equipment. In this paper, using 5 types of GDT, experiments were conducted on response characteristics when voltage waveforms having varying wavefront lengths were applied to investigate the response characteristics. Specially, the response characteristics for steep wavefront are specified.
{"title":"Response characteristics of diode gas discharge tubes","authors":"Y. Naito","doi":"10.1109/ICLP.2012.6344335","DOIUrl":"https://doi.org/10.1109/ICLP.2012.6344335","url":null,"abstract":"As a method for protecting electronic equipments from lightning attacks, mounting of SPD (surge protective device) which consists of a gas discharge tube (GDT), metal oxide varistor (MOV), and others is useful. In protecting equipment by SPD, overvoltage protection and energy harmonization become important. Above all, when overvoltage protection is thought of, response characteristics become important. Response characteristics depend on wavefront length and peak value applied to the equipment. In this paper, using 5 types of GDT, experiments were conducted on response characteristics when voltage waveforms having varying wavefront lengths were applied to investigate the response characteristics. Specially, the response characteristics for steep wavefront are specified.","PeriodicalId":400743,"journal":{"name":"2012 International Conference on Lightning Protection (ICLP)","volume":"65 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":"129332099","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.2012.6344344
S. Wyderka, G. Masłowski, R. Ziemba, G. Karnas
Investigations were conducted aimed on examination of frequency characteristics of middle to low voltage distribution transformer used to supply residential buildings. Two methods were used for the investigations. First, the impedances (absolute values and angles) of transformer middle and low voltage windings were measured and registered using precision LCR meter for frequency range from 20 Hz to 10 MHz. These impedance characteristics were also examined using voltage surge generator and digital oscilloscope. Registered voltage and current waveforms were denoised and transformed to frequency domain. Apart from investigation of distribution transformer the frequency characteristic of input impedances of typical household electrical appliances were examined using the LCR meter. The conducted measurements are significant part of investigations concerning the lightning and overvoltage protection of residential buildings, which are conducted at the test site belonging to Rzeszow University of Technology.
{"title":"Frequency characteristics of supplying transformer and electrical appliances of residential building in modeling of lightning current distribution","authors":"S. Wyderka, G. Masłowski, R. Ziemba, G. Karnas","doi":"10.1109/ICLP.2012.6344344","DOIUrl":"https://doi.org/10.1109/ICLP.2012.6344344","url":null,"abstract":"Investigations were conducted aimed on examination of frequency characteristics of middle to low voltage distribution transformer used to supply residential buildings. Two methods were used for the investigations. First, the impedances (absolute values and angles) of transformer middle and low voltage windings were measured and registered using precision LCR meter for frequency range from 20 Hz to 10 MHz. These impedance characteristics were also examined using voltage surge generator and digital oscilloscope. Registered voltage and current waveforms were denoised and transformed to frequency domain. Apart from investigation of distribution transformer the frequency characteristic of input impedances of typical household electrical appliances were examined using the LCR meter. The conducted measurements are significant part of investigations concerning the lightning and overvoltage protection of residential buildings, which are conducted at the test site belonging to Rzeszow University of Technology.","PeriodicalId":400743,"journal":{"name":"2012 International Conference on Lightning Protection (ICLP)","volume":"20 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":"124958708","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.2012.6344258
L. Fang, Qin Binquan
The regional division of lightening vulnerability for Chongqing area was carried out using six factors including average lightning current strength, lightning day, ground flash density, disaster frequency, GDP loss modulus and life vulnerable modulus. The analysis was based on the data provided by ADTD lightning location system in Chongqing from 2007 to 2010, and lightening disaster statistics of the Lightening Disaster Database in Chongqing from 1999 to 2008The forty counties of Chongqing was grouped into low, mid, high, and extreme vulnerability regions. The division was validated by one way ANOVA analysis. Grey correlation theory was applied to assess the relative correlation of the six factors with a focus on life vulnerable modulus. The most influential factor to the life vulnerable factor of lightning disaster in Chongqing was found to be the economic loss modulus. The results provide a scientific basis for preventing and reducing lightening disasters in Chongqing area.
{"title":"Analysis and exploration for vulnerability regionalization and grey relevancy between factors of lightning disaster in recent year in Chongqing","authors":"L. Fang, Qin Binquan","doi":"10.1109/ICLP.2012.6344258","DOIUrl":"https://doi.org/10.1109/ICLP.2012.6344258","url":null,"abstract":"The regional division of lightening vulnerability for Chongqing area was carried out using six factors including average lightning current strength, lightning day, ground flash density, disaster frequency, GDP loss modulus and life vulnerable modulus. The analysis was based on the data provided by ADTD lightning location system in Chongqing from 2007 to 2010, and lightening disaster statistics of the Lightening Disaster Database in Chongqing from 1999 to 2008The forty counties of Chongqing was grouped into low, mid, high, and extreme vulnerability regions. The division was validated by one way ANOVA analysis. Grey correlation theory was applied to assess the relative correlation of the six factors with a focus on life vulnerable modulus. The most influential factor to the life vulnerable factor of lightning disaster in Chongqing was found to be the economic loss modulus. The results provide a scientific basis for preventing and reducing lightening disasters in Chongqing area.","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":"130845654","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.2012.6344250
N. Rameli, M. Kadir, M. Izadi, Chandima Gomes, J. Jasni
This paper investigates the influence of inclined lightning channel on induced voltage on the line. The angle variations of inclined lightning channel may cause the voltage to be induced at different values for different points along the power line. This behaviour may affect the line's lightning performance if the peak of induced voltage is greater than the critical flashover voltage (CFO) of the line. This induced voltage is expected to be increased when the inclined angle with respect to the observation point is decreased. Appropriate method of induced voltage algorithm with respect to the incline lightning channel will be developed and compared with other method. The outcome of this study would be useful for the utility for their planning and selection of appropriate protection scheme for the line.
{"title":"On the influence of inclined lightning channel on lightning induced voltage evaluation","authors":"N. Rameli, M. Kadir, M. Izadi, Chandima Gomes, J. Jasni","doi":"10.1109/ICLP.2012.6344250","DOIUrl":"https://doi.org/10.1109/ICLP.2012.6344250","url":null,"abstract":"This paper investigates the influence of inclined lightning channel on induced voltage on the line. The angle variations of inclined lightning channel may cause the voltage to be induced at different values for different points along the power line. This behaviour may affect the line's lightning performance if the peak of induced voltage is greater than the critical flashover voltage (CFO) of the line. This induced voltage is expected to be increased when the inclined angle with respect to the observation point is decreased. Appropriate method of induced voltage algorithm with respect to the incline lightning channel will be developed and compared with other method. The outcome of this study would be useful for the utility for their planning and selection of appropriate protection scheme for the line.","PeriodicalId":400743,"journal":{"name":"2012 International Conference on Lightning Protection (ICLP)","volume":"50 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":"131202708","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.2012.6344414
S. Buba, C. Gomes, M. A. Ab. Kadir
Lightning related accidents in Nigeria, a country of high lightning density, have been collected and analyzed. Results show that lightning related human injuries and deaths are very high in Nigeria, where the actual figure may reach as high as 500 deaths per year. However, due to the social stigma attached to lightning incidents and the lack of unbroken news chains reaching media, collection of accurate statistics has become a daunting task. Apart from human and livestock related hazards; property damage is also of high concern due to probable devastating consequences of such incidents. Extra attention has been paid on collecting damage records related to aviation industry as there are several serious accidents related to lightning have been reported in this area. The data collected and analysed is used to develop a set of national level recommendations for lighting safety and protection which can also be applicable in neighbouring countries, as they also experience extremely high lightning occurrence density.
{"title":"Lightning accidents in Nigeria: With special attention to aviation mishaps","authors":"S. Buba, C. Gomes, M. A. Ab. Kadir","doi":"10.1109/ICLP.2012.6344414","DOIUrl":"https://doi.org/10.1109/ICLP.2012.6344414","url":null,"abstract":"Lightning related accidents in Nigeria, a country of high lightning density, have been collected and analyzed. Results show that lightning related human injuries and deaths are very high in Nigeria, where the actual figure may reach as high as 500 deaths per year. However, due to the social stigma attached to lightning incidents and the lack of unbroken news chains reaching media, collection of accurate statistics has become a daunting task. Apart from human and livestock related hazards; property damage is also of high concern due to probable devastating consequences of such incidents. Extra attention has been paid on collecting damage records related to aviation industry as there are several serious accidents related to lightning have been reported in this area. The data collected and analysed is used to develop a set of national level recommendations for lighting safety and protection which can also be applicable in neighbouring countries, as they also experience extremely high lightning occurrence density.","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":"131203946","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.2012.6344402
M. Becerra
Previous studies in the literature have suggested that glow corona discharges could be potentially used to control the frequency of lightning flashes to grounded objects. Such studies use simplified one-dimensional corona drift models or basic empirical equations derived from high voltage experiments to assess the effect of glow corona on the initiation of both streamers and upward connecting leaders under the influence of a descending lightning leader. In order to revisit the theoretical basis of these studies, a two-dimensional glow corona drift model has been implemented together with a self-consistent upward leader inception and propagation model -SLIM-. A 60 m tall lightning rod is used as a study case. It is found that the shielding effect of the glow corona space charge has been strongly overestimated in the literature. Furthermore, it is shown that streamers under the influence of a descending leader are initiated significantly earlier from the cylindrical body rather than from the corona-emitting area of the rod. Considering the effective shielding potential of glow corona, it is also shown that the presence of glow corona reduces the downward lightning attractiveness of 60 m tall lightning rods by less than 15%. This result shows that the efficiency of lightning rods is not strongly influenced by the generation of glow corona as opposed to the suggestions of previous studies.
{"title":"Glow corona discharges and their effect on lightning attachment: Revisited","authors":"M. Becerra","doi":"10.1109/ICLP.2012.6344402","DOIUrl":"https://doi.org/10.1109/ICLP.2012.6344402","url":null,"abstract":"Previous studies in the literature have suggested that glow corona discharges could be potentially used to control the frequency of lightning flashes to grounded objects. Such studies use simplified one-dimensional corona drift models or basic empirical equations derived from high voltage experiments to assess the effect of glow corona on the initiation of both streamers and upward connecting leaders under the influence of a descending lightning leader. In order to revisit the theoretical basis of these studies, a two-dimensional glow corona drift model has been implemented together with a self-consistent upward leader inception and propagation model -SLIM-. A 60 m tall lightning rod is used as a study case. It is found that the shielding effect of the glow corona space charge has been strongly overestimated in the literature. Furthermore, it is shown that streamers under the influence of a descending leader are initiated significantly earlier from the cylindrical body rather than from the corona-emitting area of the rod. Considering the effective shielding potential of glow corona, it is also shown that the presence of glow corona reduces the downward lightning attractiveness of 60 m tall lightning rods by less than 15%. This result shows that the efficiency of lightning rods is not strongly influenced by the generation of glow corona as opposed to the suggestions of previous studies.","PeriodicalId":400743,"journal":{"name":"2012 International Conference on Lightning Protection (ICLP)","volume":"7 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":"116168795","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.2012.6344371
E. Nicolopoulou, F. Asimakopoulou, I. Gonos, I. Stathopulos
The main characteristic of the transient behaviour of a grounding system is the decrease of the soil resistivity and consequently of the grounding impedance, due to soil ionization phenomena that take place, when the density of the injected current exceeds a critical value. In this paper two circuit models proposed by researchers have been implemented using the ATP/EMTP programme in order to simulate the transient response of a grounding system taking soil ionization into account. The simulation results are compared to measurements received by imposing impulse voltages on soil samples. The accuracy of each model is evaluated according to the level of proximity to the oscillogramms and conclusions are drawn about the effectiveness of each modeling approach.
{"title":"Comparison of circuit models for the simulation of soil ionization","authors":"E. Nicolopoulou, F. Asimakopoulou, I. Gonos, I. Stathopulos","doi":"10.1109/ICLP.2012.6344371","DOIUrl":"https://doi.org/10.1109/ICLP.2012.6344371","url":null,"abstract":"The main characteristic of the transient behaviour of a grounding system is the decrease of the soil resistivity and consequently of the grounding impedance, due to soil ionization phenomena that take place, when the density of the injected current exceeds a critical value. In this paper two circuit models proposed by researchers have been implemented using the ATP/EMTP programme in order to simulate the transient response of a grounding system taking soil ionization into account. The simulation results are compared to measurements received by imposing impulse voltages on soil samples. The accuracy of each model is evaluated according to the level of proximity to the oscillogramms and conclusions are drawn about the effectiveness of each modeling approach.","PeriodicalId":400743,"journal":{"name":"2012 International Conference on Lightning Protection (ICLP)","volume":"10 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":"127054526","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.2012.6344353
T. Gazizov, A. Zabolotsky, A. Melkozerov, E. S. Dolganov, P. Orlov
A new approach to the protection of electronics is considered to comply better with the requirements of lightning protection. Input power distribution in modal filter (MF) resistive terminations is analyzed. Dependencies of the MF power dissipation on the excitation pulse parameters have been obtained for 1-, 2-, 3-, 4-stage MF with fixed total length. Conclusions reveal potentially vulnerable parts which should be improved in order to prevent the MF failure due to overload of certain parts.
{"title":"Analysis of power dissipation in resistive terminations of single- and multistage modal filters","authors":"T. Gazizov, A. Zabolotsky, A. Melkozerov, E. S. Dolganov, P. Orlov","doi":"10.1109/ICLP.2012.6344353","DOIUrl":"https://doi.org/10.1109/ICLP.2012.6344353","url":null,"abstract":"A new approach to the protection of electronics is considered to comply better with the requirements of lightning protection. Input power distribution in modal filter (MF) resistive terminations is analyzed. Dependencies of the MF power dissipation on the excitation pulse parameters have been obtained for 1-, 2-, 3-, 4-stage MF with fixed total length. Conclusions reveal potentially vulnerable parts which should be improved in order to prevent the MF failure due to overload of certain parts.","PeriodicalId":400743,"journal":{"name":"2012 International Conference on Lightning Protection (ICLP)","volume":"13 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":"129046054","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.2012.6344311
K. Michishita, R. Sakai, S. Yokoyama, H. Nakata
For the effective insulation design of a medium-voltage line, it is important to estimate flashover rate accurately. In this paper, flashover rate due to direct strokes to the line is evaluated by using peak currents obtained in southern Kyushu by the JLDN. In the evaluation, the correlation between the front duration and the peak current is taken into account as well as the low-voltage line. As the result, the estimated flashover rate for the flash is in reasonable agreement with the observed rate.
{"title":"Flashover rate of medium-voltage line estimated with lightning parameters in Japan","authors":"K. Michishita, R. Sakai, S. Yokoyama, H. Nakata","doi":"10.1109/ICLP.2012.6344311","DOIUrl":"https://doi.org/10.1109/ICLP.2012.6344311","url":null,"abstract":"For the effective insulation design of a medium-voltage line, it is important to estimate flashover rate accurately. In this paper, flashover rate due to direct strokes to the line is evaluated by using peak currents obtained in southern Kyushu by the JLDN. In the evaluation, the correlation between the front duration and the peak current is taken into account as well as the low-voltage line. As the result, the estimated flashover rate for the flash is in reasonable agreement with the observed rate.","PeriodicalId":400743,"journal":{"name":"2012 International Conference on Lightning Protection (ICLP)","volume":"28 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":"132649896","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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