Pub Date : 2022-10-02DOI: 10.1109/ICLP56858.2022.9942454
Ndiadia Kandolo Emmanuel, Rostha Loha Paulo, Tondozi Keto Francois, Tshitenge Mbuebue Jean Marie, Kayembe Kalombo Jean Claude, Phuku Phuati Edmond
The aims of this paper is to compare the lightning activity (number of lightning flashes) of mesoscale convective systems over North and South Equatorial Africa. It examines also the correlation between the lightning activity in the Northern Equatorial Africa and that in the Southern one. Indeed, spatial observations have shown that the highest concentrations of lightning on the Earth are mostly located in Equatorial Africa. This study has been made using data processing, descriptive statistical analysis and wavelet coherence analysis. The obtained results show that there is more lightning activity in the North region of Equatorial Africa than in the South one, in an average ratio of about 1.12 to 1. At the same time, a North-South regional contrast in lightning activity is observed over the Equatorial Africa. Concerning their relationships, it has been found that the lightning activity is strongly and negatively correlated (R=-0.588) between the two hemispheres. Furthermore, using the wavelet method we have obtained the same results. The degree of linearity between the lightning activity signals S1 of the Northern Equatorial Africa and S2 of the Southern one has been characterized (linear correlation level between 0 and 1) for any time-scale location and shows that the interactions between the two signals are at sub-annual and seasonal scales, with a relative phase difference of 180° (in phase opposition). Thus, the two signals are negatively correlated. Lightning activity shows very high trends in both sub-regions and the variation in its monthly as well as seasonal mean could be explained given the strong convection and thunderstorms throughout the region.
{"title":"Comparative study of lightning activity over north vs south Equatorial Africa","authors":"Ndiadia Kandolo Emmanuel, Rostha Loha Paulo, Tondozi Keto Francois, Tshitenge Mbuebue Jean Marie, Kayembe Kalombo Jean Claude, Phuku Phuati Edmond","doi":"10.1109/ICLP56858.2022.9942454","DOIUrl":"https://doi.org/10.1109/ICLP56858.2022.9942454","url":null,"abstract":"The aims of this paper is to compare the lightning activity (number of lightning flashes) of mesoscale convective systems over North and South Equatorial Africa. It examines also the correlation between the lightning activity in the Northern Equatorial Africa and that in the Southern one. Indeed, spatial observations have shown that the highest concentrations of lightning on the Earth are mostly located in Equatorial Africa. This study has been made using data processing, descriptive statistical analysis and wavelet coherence analysis. The obtained results show that there is more lightning activity in the North region of Equatorial Africa than in the South one, in an average ratio of about 1.12 to 1. At the same time, a North-South regional contrast in lightning activity is observed over the Equatorial Africa. Concerning their relationships, it has been found that the lightning activity is strongly and negatively correlated (R=-0.588) between the two hemispheres. Furthermore, using the wavelet method we have obtained the same results. The degree of linearity between the lightning activity signals S1 of the Northern Equatorial Africa and S2 of the Southern one has been characterized (linear correlation level between 0 and 1) for any time-scale location and shows that the interactions between the two signals are at sub-annual and seasonal scales, with a relative phase difference of 180° (in phase opposition). Thus, the two signals are negatively correlated. Lightning activity shows very high trends in both sub-regions and the variation in its monthly as well as seasonal mean could be explained given the strong convection and thunderstorms throughout the region.","PeriodicalId":403323,"journal":{"name":"2022 36th International Conference on Lightning Protection (ICLP)","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122893788","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 : 2022-10-02DOI: 10.1109/ICLP56858.2022.9942623
Simisi Mosamane, Chandima Gomes
The need for a good quality power supply in PV systems makes lightning protection one of the primary requirements in Photovoltaic installations (PVIs). Surge Protective Devices (SPDs) are connected to the DC and AC cables in PVIs to protect the electronic components against lightning transients. In this paper, the protection of the microinverter against lightning transients was investigated by simulation using Power System Computer-Aided Design (PSCAD) software. A Metal Oxide Varistor (MOV) surge protective device was connected to the DC cables of a PV panel with a microinverter while subjected to lightning-induced overvoltage (LIO) stresses for various lightning current waveforms, amplitudes, and protection scenarios. This investigation measured the energy overload and the current flowing through the SPD. The results demonstrated that a class II internal SPD seems appropriate for PV installations with a microinverter with and without an external lightning protection system (LPS) for impulse currents not exceeding 20 kA.
{"title":"Lightning-induced overvoltage protection for microinverters using surge protective devices","authors":"Simisi Mosamane, Chandima Gomes","doi":"10.1109/ICLP56858.2022.9942623","DOIUrl":"https://doi.org/10.1109/ICLP56858.2022.9942623","url":null,"abstract":"The need for a good quality power supply in PV systems makes lightning protection one of the primary requirements in Photovoltaic installations (PVIs). Surge Protective Devices (SPDs) are connected to the DC and AC cables in PVIs to protect the electronic components against lightning transients. In this paper, the protection of the microinverter against lightning transients was investigated by simulation using Power System Computer-Aided Design (PSCAD) software. A Metal Oxide Varistor (MOV) surge protective device was connected to the DC cables of a PV panel with a microinverter while subjected to lightning-induced overvoltage (LIO) stresses for various lightning current waveforms, amplitudes, and protection scenarios. This investigation measured the energy overload and the current flowing through the SPD. The results demonstrated that a class II internal SPD seems appropriate for PV installations with a microinverter with and without an external lightning protection system (LPS) for impulse currents not exceeding 20 kA.","PeriodicalId":403323,"journal":{"name":"2022 36th International Conference on Lightning Protection (ICLP)","volume":"74 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131541085","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 : 2022-10-02DOI: 10.1109/ICLP56858.2022.9942512
A. Gomes, A. Rousseau, M. Guthrie, A. Barwise, Chandima Gomes
This paper discusses the issues encountered by design engineers due to the lack of a method specified in IEe 62305–2 to conduct the risk assessment only for the solar PV system mounted on a part of a large roof. Typically, the Solar PV system provider is a party independent from the building contractor and the building owner, thus, they would be interested only in the protection of the PV system rather than the total building. On the other hand, a lightning strike to the parts of the roof beyond the PV panel may also affect the PV system due to fire hazards and injected (or induced) current into the power system. Thus, it may not be advisable to consider only the part of the building with a PV panel as an isolated system. In this study we first show the difference in the risk level by conducting the risk assessment for a hypothetical case of a roof-mounted solar PV system, considering the entire building and the part of the building with PV panel on the rooftop as an isolated structure in the presence of the other parts. The computations show a significant difference in the outcomes for the two cases. We also discuss other methods adopted by lightning protection professionals in the region in computing the lightning risk for roof-mounted solar PV systems. The key objective of this study is to demonstrate the confusion concerning this subject rather than proposing a solid methodology for conducting the risk assessment for roof-mounted solar PV systems. It is of prime importance for the working groups of standards committees to come to an agreement in this regard.
{"title":"Risk Assessment of Rooftop-Mounted Solar PV Systems","authors":"A. Gomes, A. Rousseau, M. Guthrie, A. Barwise, Chandima Gomes","doi":"10.1109/ICLP56858.2022.9942512","DOIUrl":"https://doi.org/10.1109/ICLP56858.2022.9942512","url":null,"abstract":"This paper discusses the issues encountered by design engineers due to the lack of a method specified in IEe 62305–2 to conduct the risk assessment only for the solar PV system mounted on a part of a large roof. Typically, the Solar PV system provider is a party independent from the building contractor and the building owner, thus, they would be interested only in the protection of the PV system rather than the total building. On the other hand, a lightning strike to the parts of the roof beyond the PV panel may also affect the PV system due to fire hazards and injected (or induced) current into the power system. Thus, it may not be advisable to consider only the part of the building with a PV panel as an isolated system. In this study we first show the difference in the risk level by conducting the risk assessment for a hypothetical case of a roof-mounted solar PV system, considering the entire building and the part of the building with PV panel on the rooftop as an isolated structure in the presence of the other parts. The computations show a significant difference in the outcomes for the two cases. We also discuss other methods adopted by lightning protection professionals in the region in computing the lightning risk for roof-mounted solar PV systems. The key objective of this study is to demonstrate the confusion concerning this subject rather than proposing a solid methodology for conducting the risk assessment for roof-mounted solar PV systems. It is of prime importance for the working groups of standards committees to come to an agreement in this regard.","PeriodicalId":403323,"journal":{"name":"2022 36th International Conference on Lightning Protection (ICLP)","volume":"82 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133857844","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 : 2022-10-02DOI: 10.1109/ICLP56858.2022.9942472
F. Grange, S. Journet, F. Dawalibi, Zainal Kadir
Photovoltaic (PV) power plants cover large areas that are susceptible to multiple lightning strikes. Consequences of the electromagnetic interference caused by lightning can be a major concern for people safety and equipment integrity. In this paper, we investigate lightning overvoltage and transient ground potential rise in large PV plants for different lightning strike scenarios. The main objectives of this paper is to describe the analysis that was carried out and propose cost-effective mitigation techniques based on the most advanced simulation techniques.
{"title":"Lightning Overvoltage and Transient Ground Potential Rise in large PV plants","authors":"F. Grange, S. Journet, F. Dawalibi, Zainal Kadir","doi":"10.1109/ICLP56858.2022.9942472","DOIUrl":"https://doi.org/10.1109/ICLP56858.2022.9942472","url":null,"abstract":"Photovoltaic (PV) power plants cover large areas that are susceptible to multiple lightning strikes. Consequences of the electromagnetic interference caused by lightning can be a major concern for people safety and equipment integrity. In this paper, we investigate lightning overvoltage and transient ground potential rise in large PV plants for different lightning strike scenarios. The main objectives of this paper is to describe the analysis that was carried out and propose cost-effective mitigation techniques based on the most advanced simulation techniques.","PeriodicalId":403323,"journal":{"name":"2022 36th International Conference on Lightning Protection (ICLP)","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122091743","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 : 2022-10-02DOI: 10.1109/ICLP56858.2022.9942641
C. Schumann, Hugh G. P. Hunt, Jason Smitt, T. Warner
Upward flashes are one of the most increasing topics of study in the lightning science community, due to the increase of tall structures, such as tall wind turbines and tall buildings. During the period from January 2017 to January 2020, a total of 99 upward flashes were observed in Johannesburg, South Africa. This paper presents the analysis of prior activity observed by high- speed cameras as well as the polarity of the leader and other leader characteristics. The data from lightning location network associated with the cases is also presented in this paper. The cases showed an initial continuous current duration of 417.3ms, and during this continuous current the presence of 1,000 ICC pulses was observed. Another characteristic observed was that 41 % of the cases had subsequent return strokes and that the average duration of the subsequent return strokes was 22ms, and only 10% were longer than 40ms (as per definition of long continuing current).
{"title":"Optical Observations of 99 Upward Flashes in Johannesburg, South Africa","authors":"C. Schumann, Hugh G. P. Hunt, Jason Smitt, T. Warner","doi":"10.1109/ICLP56858.2022.9942641","DOIUrl":"https://doi.org/10.1109/ICLP56858.2022.9942641","url":null,"abstract":"Upward flashes are one of the most increasing topics of study in the lightning science community, due to the increase of tall structures, such as tall wind turbines and tall buildings. During the period from January 2017 to January 2020, a total of 99 upward flashes were observed in Johannesburg, South Africa. This paper presents the analysis of prior activity observed by high- speed cameras as well as the polarity of the leader and other leader characteristics. The data from lightning location network associated with the cases is also presented in this paper. The cases showed an initial continuous current duration of 417.3ms, and during this continuous current the presence of 1,000 ICC pulses was observed. Another characteristic observed was that 41 % of the cases had subsequent return strokes and that the average duration of the subsequent return strokes was 22ms, and only 10% were longer than 40ms (as per definition of long continuing current).","PeriodicalId":403323,"journal":{"name":"2022 36th International Conference on Lightning Protection (ICLP)","volume":"68 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134027119","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 : 2022-10-02DOI: 10.1109/ICLP56858.2022.9942468
S. Pack, J. Schröttner
Lightning strikes often pose a great risk to humans and their surroundings. Due to the numerous lightning strikes in Styria (province of Austria) individuals are occasionally struck directly or indirectly by lightning. The majority of the victims survived, however carrying away damages to health, varying in their severity. In the period from 2000 to 2017 22 lightning accidents with 55 lightning victims were reported by the local police department, four of the victims not surviving the impact or their consequences. The lightning accidents are analyzed according to several indications, such as daytime of the accident, age and gender of the victims, mechanisms of energy transmission to the human body, visible trails of the current path and amplitudes of the lightning current of the detected strokes, which were compared with data from the literature. The circumstances of the accidents, the effects of the lightning currents on the human body and the medical consequences were very different for all lightning stroke victims in Styria, but all injury patterns described as characteristic in the literature occurred. On average, two people per year were injured by direct or indirect lightning in this area. It could be shown that the amplitude of the lightning stroke is not crucial for the severity of the accidents or the survival of the victims.
{"title":"A 17 -year retrospective review of lightning victims in Austria with focus on lightning effects","authors":"S. Pack, J. Schröttner","doi":"10.1109/ICLP56858.2022.9942468","DOIUrl":"https://doi.org/10.1109/ICLP56858.2022.9942468","url":null,"abstract":"Lightning strikes often pose a great risk to humans and their surroundings. Due to the numerous lightning strikes in Styria (province of Austria) individuals are occasionally struck directly or indirectly by lightning. The majority of the victims survived, however carrying away damages to health, varying in their severity. In the period from 2000 to 2017 22 lightning accidents with 55 lightning victims were reported by the local police department, four of the victims not surviving the impact or their consequences. The lightning accidents are analyzed according to several indications, such as daytime of the accident, age and gender of the victims, mechanisms of energy transmission to the human body, visible trails of the current path and amplitudes of the lightning current of the detected strokes, which were compared with data from the literature. The circumstances of the accidents, the effects of the lightning currents on the human body and the medical consequences were very different for all lightning stroke victims in Styria, but all injury patterns described as characteristic in the literature occurred. On average, two people per year were injured by direct or indirect lightning in this area. It could be shown that the amplitude of the lightning stroke is not crucial for the severity of the accidents or the survival of the victims.","PeriodicalId":403323,"journal":{"name":"2022 36th International Conference on Lightning Protection (ICLP)","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133862246","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 : 2022-10-02DOI: 10.1109/ICLP56858.2022.9942494
Biagione Rangel de Araújo
This article presents a study on the values of the partitioning coefficient kc of the lightning current amongst the air-terminations/down-conductors, which depend on the type of air-termination system established by the Brazilian and International Standards for Lightning Protection Systems. For the present study, a model was developed by means of specific arrangements of inductive impedances for several specific configurations. However, the arrangements do not cover evaluations of electromagnetic couplings with installations or metallic parts inside structures or buildings. Such model is detailed throughout the paper. The methodology used converts the length of the conductor's air-terminations system and down-conductor into equivalent inductances. An equivalent circuit of inductive impedances was elaborated from the cited model. And from this, equations were synthesized, and tables where the shown kc values calculated from the modeling and compared with the values were simulated with the software ATPDraw 6.0. The values calculated by the equations established according to the mentioned standards. The obtained results converge between the values simulated and calculated by equations and have a significant deviation of up to 57% in relation to the values simulated by the equations of the standards mentioned, depending on the length of the down-conductors. Considering such information and considering that the safety distance or separation distance 's' is directly related to the ‘kc’ factor, the conclusion is to recommend an evaluation of the equations for the calculation of such factor. Thus, in our understanding, the safety distance will be more effective for mitigating dangerous sparks that could cause damage to people and structures.
{"title":"Study of kc coefficient values established in the Brazilian and International Standards for Lightning Protection Systems","authors":"Biagione Rangel de Araújo","doi":"10.1109/ICLP56858.2022.9942494","DOIUrl":"https://doi.org/10.1109/ICLP56858.2022.9942494","url":null,"abstract":"This article presents a study on the values of the partitioning coefficient kc of the lightning current amongst the air-terminations/down-conductors, which depend on the type of air-termination system established by the Brazilian and International Standards for Lightning Protection Systems. For the present study, a model was developed by means of specific arrangements of inductive impedances for several specific configurations. However, the arrangements do not cover evaluations of electromagnetic couplings with installations or metallic parts inside structures or buildings. Such model is detailed throughout the paper. The methodology used converts the length of the conductor's air-terminations system and down-conductor into equivalent inductances. An equivalent circuit of inductive impedances was elaborated from the cited model. And from this, equations were synthesized, and tables where the shown kc values calculated from the modeling and compared with the values were simulated with the software ATPDraw 6.0. The values calculated by the equations established according to the mentioned standards. The obtained results converge between the values simulated and calculated by equations and have a significant deviation of up to 57% in relation to the values simulated by the equations of the standards mentioned, depending on the length of the down-conductors. Considering such information and considering that the safety distance or separation distance 's' is directly related to the ‘kc’ factor, the conclusion is to recommend an evaluation of the equations for the calculation of such factor. Thus, in our understanding, the safety distance will be more effective for mitigating dangerous sparks that could cause damage to people and structures.","PeriodicalId":403323,"journal":{"name":"2022 36th International Conference on Lightning Protection (ICLP)","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133422923","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 : 2022-10-02DOI: 10.1109/ICLP56858.2022.9942613
Kazuo Yamamoto, Hiroaki Kazui, Shota Izuchi
There are usually no high structures that block the wind around a wind turbine. Therefore, wind turbines are often struck by lightning. From such a background, “Interpretation of technical standards for wind power generation systems” was revised in Japan, it was obligatory to stop the operation of the wind turbine with an emergency stop system and to restart the operation after confirming the soundness when a lightning detection system installed on the wind turbine detects a lightning strike. But it may take time to restart because sometimes it is difficult to visit the wind turbine for immediate inspection after stopping. In this paper, we investigated the influence of lightning strikes to wind turbines on the availability. In order to consider countermeasures to improve the availability, it is necessary to understand lightning damage situations of the wind turbine. According to the periodic safety management review system in Japan, blade inspection data and maintenance data of each wind turbine had to be recorded. Based on these data, we also report the relationship between lightning damage and lightning parameters.
{"title":"Influence of Lightning Strike on Availability of Wind Turbine and its Damage Analysis","authors":"Kazuo Yamamoto, Hiroaki Kazui, Shota Izuchi","doi":"10.1109/ICLP56858.2022.9942613","DOIUrl":"https://doi.org/10.1109/ICLP56858.2022.9942613","url":null,"abstract":"There are usually no high structures that block the wind around a wind turbine. Therefore, wind turbines are often struck by lightning. From such a background, “Interpretation of technical standards for wind power generation systems” was revised in Japan, it was obligatory to stop the operation of the wind turbine with an emergency stop system and to restart the operation after confirming the soundness when a lightning detection system installed on the wind turbine detects a lightning strike. But it may take time to restart because sometimes it is difficult to visit the wind turbine for immediate inspection after stopping. In this paper, we investigated the influence of lightning strikes to wind turbines on the availability. In order to consider countermeasures to improve the availability, it is necessary to understand lightning damage situations of the wind turbine. According to the periodic safety management review system in Japan, blade inspection data and maintenance data of each wind turbine had to be recorded. Based on these data, we also report the relationship between lightning damage and lightning parameters.","PeriodicalId":403323,"journal":{"name":"2022 36th International Conference on Lightning Protection (ICLP)","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133165979","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 : 2022-10-02DOI: 10.1109/ICLP56858.2022.9942456
Surekha Jonnalagadda, U. Kumar
Lightning discharges in the atmosphere can present a severe electromagnetic threat to an aircraft in flight. For testing electrical equipment as well as to verify adequacy of protective systems, lightning current waveforms are suggested in pertinent standards. These have been emerged from ground-based lightning measurements and are broadly categorized into fast, median, slow (first and subsequent strokes). Similarly, lightning current waveforms A to D for direct effects are in force in aerospace industry for certification. Waveforms A and D have rise times of median first and subsequent strokes. Component H (fast subsequent stroke) specified in standards, although is not intended for full aircraft level testing but is usually employed for indirect effect testing. Experimental methods for quantification of a lightning threat to aircraft is expensive and time-consuming. Considering the suitability of numerical computational tools for this purpose, in literature, the solution of full-wave equations using Finite Difference Time Domain (FDTD) is considered. Seeking full wave solution for aircraft's complicated geometry would be computationally challenging. As certification for direct effects of aircraft and its major parts involve only the components A and D, in this work, an assessment is made on wave effects based on frequency spectrum of these currents and typical dimensions of aircraft. It is shown that solution of diffusion equation (eddy current field) would be quite adequate for assessing lightning effects on the aircraft. For the sake of completeness, the effect of employing an eddy current approximation for fast subsequent strokes i.e. component H is also analyzed. For these currents, fields are computed on highly simplified wire-mesh model using Time Domain Thin Wire (TDTW) solution and distributed circuit-based approach.
{"title":"Identification of Suitable Governing Equation for Electromagnetic Fields in Aircrafts During a Lightning Strike","authors":"Surekha Jonnalagadda, U. Kumar","doi":"10.1109/ICLP56858.2022.9942456","DOIUrl":"https://doi.org/10.1109/ICLP56858.2022.9942456","url":null,"abstract":"Lightning discharges in the atmosphere can present a severe electromagnetic threat to an aircraft in flight. For testing electrical equipment as well as to verify adequacy of protective systems, lightning current waveforms are suggested in pertinent standards. These have been emerged from ground-based lightning measurements and are broadly categorized into fast, median, slow (first and subsequent strokes). Similarly, lightning current waveforms A to D for direct effects are in force in aerospace industry for certification. Waveforms A and D have rise times of median first and subsequent strokes. Component H (fast subsequent stroke) specified in standards, although is not intended for full aircraft level testing but is usually employed for indirect effect testing. Experimental methods for quantification of a lightning threat to aircraft is expensive and time-consuming. Considering the suitability of numerical computational tools for this purpose, in literature, the solution of full-wave equations using Finite Difference Time Domain (FDTD) is considered. Seeking full wave solution for aircraft's complicated geometry would be computationally challenging. As certification for direct effects of aircraft and its major parts involve only the components A and D, in this work, an assessment is made on wave effects based on frequency spectrum of these currents and typical dimensions of aircraft. It is shown that solution of diffusion equation (eddy current field) would be quite adequate for assessing lightning effects on the aircraft. For the sake of completeness, the effect of employing an eddy current approximation for fast subsequent strokes i.e. component H is also analyzed. For these currents, fields are computed on highly simplified wire-mesh model using Time Domain Thin Wire (TDTW) solution and distributed circuit-based approach.","PeriodicalId":403323,"journal":{"name":"2022 36th International Conference on Lightning Protection (ICLP)","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116178228","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 : 2022-10-02DOI: 10.1109/ICLP56858.2022.9942646
I. Grobbelaar, S. Weber
Lightning current transients injected onto the PV modules in large Solar Power Plants (SPPs) may cause damage to downstream connected systems, resulting in permanent equipment failure and power production down time. Surge protective devices installed to protect electronic equipment on SPPs will not be able to withstand the peak lightning currents without sufficient energy dissipation through the SPP. With the correct implementation of external lightning protection and earthing meshes, it is shown that the surge protection is not overstressed due to sufficient energy diversion and dissipation in the SPP before reaching critical equipment. The resultant current distribution, transient waveform and specific energy are calculated at critical locations in the PV field through XGSLab simulations. Advantages are shown for the strategic and cost-effective design considerations with regards to earthing, and how it reduces stress on equipment and surge protective devices during lightning events.
{"title":"External Lightning Protection and Earthing to Reduce Stress on SPDs within Electrical Equipment in Photovoltaic Plants","authors":"I. Grobbelaar, S. Weber","doi":"10.1109/ICLP56858.2022.9942646","DOIUrl":"https://doi.org/10.1109/ICLP56858.2022.9942646","url":null,"abstract":"Lightning current transients injected onto the PV modules in large Solar Power Plants (SPPs) may cause damage to downstream connected systems, resulting in permanent equipment failure and power production down time. Surge protective devices installed to protect electronic equipment on SPPs will not be able to withstand the peak lightning currents without sufficient energy dissipation through the SPP. With the correct implementation of external lightning protection and earthing meshes, it is shown that the surge protection is not overstressed due to sufficient energy diversion and dissipation in the SPP before reaching critical equipment. The resultant current distribution, transient waveform and specific energy are calculated at critical locations in the PV field through XGSLab simulations. Advantages are shown for the strategic and cost-effective design considerations with regards to earthing, and how it reduces stress on equipment and surge protective devices during lightning events.","PeriodicalId":403323,"journal":{"name":"2022 36th International Conference on Lightning Protection (ICLP)","volume":"92 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123394850","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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