Pub Date : 2016-09-01DOI: 10.1109/ICLP.2016.7791440
Ashen Gomes, Chandima Gomes, M. Ab. Kadir, M. Izadi, Michael Rock
This paper validates the performance of low-cost lightning protection systems for small structures proposed by researchers in the past. Such structures have an acute demand in the countries with very high lightning ground flash density, yet the affordability of the mass public is quite limited due to the struggling economies of the countries. The protection systems for small housing structure, and a standalone protection structure for one or few people have been investigated by implementing the structures in HFSS/ANSYS software which employs finite element method. By applying current waveforms to represent first negative return stroke, subsequent negative return stroke and positive return stroke, the electric field and potential gradient of the entire space and the current density and the thermal profile of the protective structure have been computed. The objectives were to find whether the voltage distribution in the wake of a lightning strike could initiate side flashes, generate touch potential and step potentials that exceed dangerous levels, drive current densities due to which the structure collapse under thermal effects. It has been found that the proposed protective structures could suppress side flashes and harmful effects due to step potential while the structure will be able to withstand the heat generated. However, the touch potential could still be beyond the human injury thresholds, thus a minimum separation from the lightning current passage should be advised to the occupants.
{"title":"Evaluation of lightning protection systems proposed for small structures by electromagnetic simulation","authors":"Ashen Gomes, Chandima Gomes, M. Ab. Kadir, M. Izadi, Michael Rock","doi":"10.1109/ICLP.2016.7791440","DOIUrl":"https://doi.org/10.1109/ICLP.2016.7791440","url":null,"abstract":"This paper validates the performance of low-cost lightning protection systems for small structures proposed by researchers in the past. Such structures have an acute demand in the countries with very high lightning ground flash density, yet the affordability of the mass public is quite limited due to the struggling economies of the countries. The protection systems for small housing structure, and a standalone protection structure for one or few people have been investigated by implementing the structures in HFSS/ANSYS software which employs finite element method. By applying current waveforms to represent first negative return stroke, subsequent negative return stroke and positive return stroke, the electric field and potential gradient of the entire space and the current density and the thermal profile of the protective structure have been computed. The objectives were to find whether the voltage distribution in the wake of a lightning strike could initiate side flashes, generate touch potential and step potentials that exceed dangerous levels, drive current densities due to which the structure collapse under thermal effects. It has been found that the proposed protective structures could suppress side flashes and harmful effects due to step potential while the structure will be able to withstand the heat generated. However, the touch potential could still be beyond the human injury thresholds, thus a minimum separation from the lightning current passage should be advised to the occupants.","PeriodicalId":373744,"journal":{"name":"2016 33rd International Conference on Lightning Protection (ICLP)","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131009770","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}
A recognition method of the thunder signal based on the end-point detection method with a noise-estimation algorithm for highly non-stationary environments is proposed. To determine the parameter of the algorithm and verify the effectiveness and accuracy of the method we analyze the acoustic signals obtained from two microphone arrays installed at the top platform on a seven-floor building in Wuhan. In this paper, we have chosen two acoustic signals to test the endpoint detection method. It is revealed from the recognition result that the method can find out the accurate beginning and ending time of the thunder signal from the acoustic signals.
{"title":"The recognition method of thunder based on a noise-estimation algorithm for highly non-stationary environments","authors":"Gu Shanqiang, Zhang Han, Feng Wanxing, Zhao Chun, Wu Dawei, Yan Biwu, Guo Jun-tian, Tian Hao","doi":"10.1109/ICLP.2016.7791408","DOIUrl":"https://doi.org/10.1109/ICLP.2016.7791408","url":null,"abstract":"A recognition method of the thunder signal based on the end-point detection method with a noise-estimation algorithm for highly non-stationary environments is proposed. To determine the parameter of the algorithm and verify the effectiveness and accuracy of the method we analyze the acoustic signals obtained from two microphone arrays installed at the top platform on a seven-floor building in Wuhan. In this paper, we have chosen two acoustic signals to test the endpoint detection method. It is revealed from the recognition result that the method can find out the accurate beginning and ending time of the thunder signal from the acoustic signals.","PeriodicalId":373744,"journal":{"name":"2016 33rd International Conference on Lightning Protection (ICLP)","volume":"79 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133460490","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 : 2016-09-01DOI: 10.1109/ICLP.2016.7791402
Yakun Liu, Hailiang Xia, Z. Fu, Xin Gao, Baoquan Liu
Metal ablation area and depth are affected by electrodes used in simulated lightning metal ablation experiment. In this study, electrode materials are firstly investigated to decrease electrode jet. Then nine different shapes of experiment electrodes, which are hemisphere electrode, semi-ellipsoid electrode and cone electrode with three different diameters of 6, 8 and 10mm respectively, are used to investigate the influences on metal ablation results with simulated long continuing current. The results show that, using cone electrode leads to the severest metal ablation results both in ablation area and depth, followed by using semi-ellipsoid electrode and hemisphere electrode. For electrodes of same shape, metal ablation area and depth decrease with its diameter increasing. The different ablation results caused by different shapes of electrodes are properly explained with initial electric field strength distribution analysis, subsequent dynamic electron density and electron energy density distribution analysis by the finite-element numerical analysis software of ANASYS and COMSOL Multiphysics.
{"title":"Analysis on the choosing of test electrode for lightning current metal ablation experiments","authors":"Yakun Liu, Hailiang Xia, Z. Fu, Xin Gao, Baoquan Liu","doi":"10.1109/ICLP.2016.7791402","DOIUrl":"https://doi.org/10.1109/ICLP.2016.7791402","url":null,"abstract":"Metal ablation area and depth are affected by electrodes used in simulated lightning metal ablation experiment. In this study, electrode materials are firstly investigated to decrease electrode jet. Then nine different shapes of experiment electrodes, which are hemisphere electrode, semi-ellipsoid electrode and cone electrode with three different diameters of 6, 8 and 10mm respectively, are used to investigate the influences on metal ablation results with simulated long continuing current. The results show that, using cone electrode leads to the severest metal ablation results both in ablation area and depth, followed by using semi-ellipsoid electrode and hemisphere electrode. For electrodes of same shape, metal ablation area and depth decrease with its diameter increasing. The different ablation results caused by different shapes of electrodes are properly explained with initial electric field strength distribution analysis, subsequent dynamic electron density and electron energy density distribution analysis by the finite-element numerical analysis software of ANASYS and COMSOL Multiphysics.","PeriodicalId":373744,"journal":{"name":"2016 33rd International Conference on Lightning Protection (ICLP)","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133142484","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 : 2016-09-01DOI: 10.1109/ICLP.2016.7791336
S. Xie, Jianming Li, Tao Luo, Yu Zhang, Junjia He, Chuanqi Wu, Yishi Yue
Natural lightning flashes are stochastic and uncontrollable, and thus it is difficult to observe the formation process of a downward negative stepped leader (NSL) directly and in detail. In this paper, the formation processes of NSLs in controllable laboratorial long-air-gap discharge experiments were studies. First, a series of negative long-air-gap discharge experiments with scales of 4~10 m were designed and carried out. According to the observation results of these experiments, two kinds of formation processes for NSLs with different scales were presented, and several of the characteristic parameters, including the scale, the propagation velocity and the dark period, were obtained. By comparing these characteristics with that in natural flashes, the similarity between the NSLs in the simulation experiments and those in natural flashes was proved, and the actual formation of NSLs in natural flashes was deduced.
{"title":"Formation and characteristics of negative stepped leaders in 4–10m long air gap discharges","authors":"S. Xie, Jianming Li, Tao Luo, Yu Zhang, Junjia He, Chuanqi Wu, Yishi Yue","doi":"10.1109/ICLP.2016.7791336","DOIUrl":"https://doi.org/10.1109/ICLP.2016.7791336","url":null,"abstract":"Natural lightning flashes are stochastic and uncontrollable, and thus it is difficult to observe the formation process of a downward negative stepped leader (NSL) directly and in detail. In this paper, the formation processes of NSLs in controllable laboratorial long-air-gap discharge experiments were studies. First, a series of negative long-air-gap discharge experiments with scales of 4~10 m were designed and carried out. According to the observation results of these experiments, two kinds of formation processes for NSLs with different scales were presented, and several of the characteristic parameters, including the scale, the propagation velocity and the dark period, were obtained. By comparing these characteristics with that in natural flashes, the similarity between the NSLs in the simulation experiments and those in natural flashes was proved, and the actual formation of NSLs in natural flashes was deduced.","PeriodicalId":373744,"journal":{"name":"2016 33rd International Conference on Lightning Protection (ICLP)","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115146820","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 : 2016-09-01DOI: 10.1109/ICLP.2016.7791399
M. Ignjatović, J. Cvetic, N. Mijajlovic, D. Pavlović, F. Heidler
A new form of the space charge distribution inside the channel corona sheath that represents a generalization of previously adopted or calculated space charge densities is numerically analyzed. On one hand, the use of appropriate parameter values produces the previously established corona charge densities as special cases of this generalized distribution. On the other hand, the influence of the new space charge distribution on the corona sheath dynamics can be examined. The simulations showed that the new generalized function possesses excellent features regarding flexibility in modeling of different corona sheath charge distribution. Besides, it proved to be simple and easy to calculate. Although it is applied in the generalized traveling current source model in this study, it could also be readily implemented in transmission-line type return stroke models.
{"title":"Space charge distribution inside the corona sheath during a return stroke","authors":"M. Ignjatović, J. Cvetic, N. Mijajlovic, D. Pavlović, F. Heidler","doi":"10.1109/ICLP.2016.7791399","DOIUrl":"https://doi.org/10.1109/ICLP.2016.7791399","url":null,"abstract":"A new form of the space charge distribution inside the channel corona sheath that represents a generalization of previously adopted or calculated space charge densities is numerically analyzed. On one hand, the use of appropriate parameter values produces the previously established corona charge densities as special cases of this generalized distribution. On the other hand, the influence of the new space charge distribution on the corona sheath dynamics can be examined. The simulations showed that the new generalized function possesses excellent features regarding flexibility in modeling of different corona sheath charge distribution. Besides, it proved to be simple and easy to calculate. Although it is applied in the generalized traveling current source model in this study, it could also be readily implemented in transmission-line type return stroke models.","PeriodicalId":373744,"journal":{"name":"2016 33rd International Conference on Lightning Protection (ICLP)","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128584914","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 : 2016-09-01DOI: 10.1109/ICLP.2016.7791392
D. Lian, Zhang Bo, He Jinliang, X. Leishi, Li Qian
Previous work has proven that transient characteristics of a grounding grid was far more different than its performance at power frequency because of the inductance of the system and the soil ionization phenomena. In this paper, a test on a grounding grid of a 110 kV substation was conducted. Several parameters, such as waveform, peak value and injecting point of lightning, were altered to study their relationship with transient characteristics. Not only the impulse earthing resistance but also the voltage and current distribution of the conductors were analyzed. Characteristics of grounding grid between power frequency and higher frequency were compared.
{"title":"Experimental study on transient characteristics of grounding grid for substation","authors":"D. Lian, Zhang Bo, He Jinliang, X. Leishi, Li Qian","doi":"10.1109/ICLP.2016.7791392","DOIUrl":"https://doi.org/10.1109/ICLP.2016.7791392","url":null,"abstract":"Previous work has proven that transient characteristics of a grounding grid was far more different than its performance at power frequency because of the inductance of the system and the soil ionization phenomena. In this paper, a test on a grounding grid of a 110 kV substation was conducted. Several parameters, such as waveform, peak value and injecting point of lightning, were altered to study their relationship with transient characteristics. Not only the impulse earthing resistance but also the voltage and current distribution of the conductors were analyzed. Characteristics of grounding grid between power frequency and higher frequency were compared.","PeriodicalId":373744,"journal":{"name":"2016 33rd International Conference on Lightning Protection (ICLP)","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133752775","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 : 2016-09-01DOI: 10.1109/ICLP.2016.7791503
M. Matsui, Akiko Sugita, Koji Michishita, Satoshi Kurihara, N. Honjo
The location accuracy of the Japanese Lightning Detection Network (JLDN) has been evaluated for a long time. It was reported that the average location accuracy of the JLDN was approximately 0.44 km for return strokes of negative downward lightning striking wind turbines in summer and 0.58 km for return strokes associated with upward lightning initiated from wind turbines in winter. However, the authors found that many stroke positions calculated by the JLDN tended to be located in specific directions. Therefore, we assumed this was caused by differences in the propagation speed of the electromagnetic waves that emitted from lightning discharges, passing along surfaces of varying conductivity. We recalculated the lightning positions of strokes that hit the wind turbines after applying propagation delay corrections. The difference between the times measured at the sensor and calculated times was smaller after the recalculation. As a result, location accuracy was improved from 0.44 km to 0.31 km for downward lightning strokes in summer, and it was improved from 0.79 km to 0.12 km for lightning strokes in winter.
{"title":"Discussion on location accuracy improvemed by propagation delay corrections for the Japanese lightning detection network","authors":"M. Matsui, Akiko Sugita, Koji Michishita, Satoshi Kurihara, N. Honjo","doi":"10.1109/ICLP.2016.7791503","DOIUrl":"https://doi.org/10.1109/ICLP.2016.7791503","url":null,"abstract":"The location accuracy of the Japanese Lightning Detection Network (JLDN) has been evaluated for a long time. It was reported that the average location accuracy of the JLDN was approximately 0.44 km for return strokes of negative downward lightning striking wind turbines in summer and 0.58 km for return strokes associated with upward lightning initiated from wind turbines in winter. However, the authors found that many stroke positions calculated by the JLDN tended to be located in specific directions. Therefore, we assumed this was caused by differences in the propagation speed of the electromagnetic waves that emitted from lightning discharges, passing along surfaces of varying conductivity. We recalculated the lightning positions of strokes that hit the wind turbines after applying propagation delay corrections. The difference between the times measured at the sensor and calculated times was smaller after the recalculation. As a result, location accuracy was improved from 0.44 km to 0.31 km for downward lightning strokes in summer, and it was improved from 0.79 km to 0.12 km for lightning strokes in winter.","PeriodicalId":373744,"journal":{"name":"2016 33rd International Conference on Lightning Protection (ICLP)","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132787051","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 : 2016-09-01DOI: 10.1109/ICLP.2016.7791458
J. Paulino, W. Boaventura, Celio Fonseca Barbosa
This paper analyzed the effect of the multi-grounded neutral on the peak values and waveforms of the lightning induced voltages (LIVs) in an overhead power distribution line. The results show that the LIV waveforms observed close to a neutral grounding point are smooth, while those observed around the mid-point between two consecutive grounding points are oscillatory. The waveform oscillations are reduced with reducing the spacing between grounding points, increasing the distance between the strike and the line, and increasing the value of ground resistivity. For a first negative stroke, these oscillations can be neglected if the distance between the strike and the line is higher than 50 m and the spacing between grounding points is shorter than 200 m. It is also shown that, under certain conditions, the indirect lightning flashover rate of a line with multi-grounded neutral can be assessed from the peak-values of the LIVs of a single wire above ground.
{"title":"Effect of the multi-grounded neutral on the lightning induced voltages in an overhead power line","authors":"J. Paulino, W. Boaventura, Celio Fonseca Barbosa","doi":"10.1109/ICLP.2016.7791458","DOIUrl":"https://doi.org/10.1109/ICLP.2016.7791458","url":null,"abstract":"This paper analyzed the effect of the multi-grounded neutral on the peak values and waveforms of the lightning induced voltages (LIVs) in an overhead power distribution line. The results show that the LIV waveforms observed close to a neutral grounding point are smooth, while those observed around the mid-point between two consecutive grounding points are oscillatory. The waveform oscillations are reduced with reducing the spacing between grounding points, increasing the distance between the strike and the line, and increasing the value of ground resistivity. For a first negative stroke, these oscillations can be neglected if the distance between the strike and the line is higher than 50 m and the spacing between grounding points is shorter than 200 m. It is also shown that, under certain conditions, the indirect lightning flashover rate of a line with multi-grounded neutral can be assessed from the peak-values of the LIVs of a single wire above ground.","PeriodicalId":373744,"journal":{"name":"2016 33rd International Conference on Lightning Protection (ICLP)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133447660","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 : 2016-09-01DOI: 10.1109/ICLP.2016.7791511
D. Belko, G. V. Podporkin
The paper presents ATP-EMTP software simulation of a direct lightning strike (DLS) into the one phase conductor of 10 kV overhead line (OHL). The model takes into account the influence of induced overvoltages (IOV) from the lightning leader. There have been obtained distributions of surge current among modular long-flashover arresters (LFA-M) mounted on the poles depending on the lightning strike location and pole footing resistance. The three principal types of impulses flowing through the arresters of each phase have been revealed. It has been discovered that a current impulse shape at arresters can greatly differ from that of lightning.
{"title":"Analysis of current distribution among long-flashover arresters for 10 kV overhead line protection against direct lightning strikes","authors":"D. Belko, G. V. Podporkin","doi":"10.1109/ICLP.2016.7791511","DOIUrl":"https://doi.org/10.1109/ICLP.2016.7791511","url":null,"abstract":"The paper presents ATP-EMTP software simulation of a direct lightning strike (DLS) into the one phase conductor of 10 kV overhead line (OHL). The model takes into account the influence of induced overvoltages (IOV) from the lightning leader. There have been obtained distributions of surge current among modular long-flashover arresters (LFA-M) mounted on the poles depending on the lightning strike location and pole footing resistance. The three principal types of impulses flowing through the arresters of each phase have been revealed. It has been discovered that a current impulse shape at arresters can greatly differ from that of lightning.","PeriodicalId":373744,"journal":{"name":"2016 33rd International Conference on Lightning Protection (ICLP)","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130530871","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}
Characteristics of stem play an important role in the leader inception and development, and deserve comprehensive studies. In order to observe the stem experimentally, a schlieren system was established. Experiments in a 1m cone-plane gap under positive impulse voltage were carried out and the discharge current and schlieren photographs of discharge process were recorded synchronously with associated analysis. Experimental results showed that the number of stems were always more than one at the initial stage of the discharge in long gaps. Only 3% of the cases had one stem in our experiments. The number of stems followed a normal distribution with mean 4.01 and standard deviation 1.26. The first corona charge did not have a significant impact on the number of the stems. These stems were concentrated near the cone tip in the range -4 to 4 pixel. Using the method for the position of the stems described in this paper, the distribution of the stems followed a normal distribution with an average of -0.44 and standard deviation 4.31.
{"title":"Number and dimensional distribution of stems near the anode in a 1m air gap under positive pulse","authors":"Xiangen Zhao, Junjia He, Hengxin He, Yishi Yue, Weijiang Chen","doi":"10.1109/ICLP.2016.7791504","DOIUrl":"https://doi.org/10.1109/ICLP.2016.7791504","url":null,"abstract":"Characteristics of stem play an important role in the leader inception and development, and deserve comprehensive studies. In order to observe the stem experimentally, a schlieren system was established. Experiments in a 1m cone-plane gap under positive impulse voltage were carried out and the discharge current and schlieren photographs of discharge process were recorded synchronously with associated analysis. Experimental results showed that the number of stems were always more than one at the initial stage of the discharge in long gaps. Only 3% of the cases had one stem in our experiments. The number of stems followed a normal distribution with mean 4.01 and standard deviation 1.26. The first corona charge did not have a significant impact on the number of the stems. These stems were concentrated near the cone tip in the range -4 to 4 pixel. Using the method for the position of the stems described in this paper, the distribution of the stems followed a normal distribution with an average of -0.44 and standard deviation 4.31.","PeriodicalId":373744,"journal":{"name":"2016 33rd International Conference on Lightning Protection (ICLP)","volume":"73 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126993193","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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