Currently,the number of lightning casualties and casualty rates have significantly reduced in developed countries,but there has been no significant reduction in developing countries.On the one hand,this is due to the ...Currently,the number of lightning casualties and casualty rates have significantly reduced in developed countries,but there has been no significant reduction in developing countries.On the one hand,this is due to the high frequency of lightning;on the other hand,the vulnerability of people in developing countries is also an influencing factor.Through case analysis and summary,this paper expounds on lightning injury s mechanism and clinical manifestations.It points out that lightning injury is mainly related to heart problems and the impact on the nervous system,rather than burns,which usually cause fewer consequences.Medical treatment needs to pay attention to the order and principles of treatment.Implementing CPR and auxiliary AED is the most effective way to save lives.Attention should be paid to the practical and effective treatment and nursing of lightning stroke sequelae.Finally,combined with the situation of lightning casualties in China,the existing problems are put forward during the process of early treatment,post-hospital treatment,and nursing observation,which provides an objective basis for the cognition of the scientific nature of the lightning injury.展开更多
This study utilizes data from a 3D lightning location system,polarimetric radar,and current measurements from channels of triggered lightning flashes(TLFs)to analyze the structural characteristics of the parent thunde...This study utilizes data from a 3D lightning location system,polarimetric radar,and current measurements from channels of triggered lightning flashes(TLFs)to analyze the structural characteristics of the parent thunderstorms associated with negative TLFs in South China.The triggered-flash region(TFR)displays distinct stratiform cloud characteristics,including lower radar reflectivity heights and a predominance of ice crystals and dry snow above the 0℃ layer.In contrast,the thunderstorm convection core region(CCR)tends to have more graupel particles in the mixed-phase layers and exhibits an ice-water content peak approximately 3.4 times that of the TFR.The charge regions involved in discharges in TFRs exhibit a dipolar charge structure,with the-5℃ layer roughly dividing the upper positive and lower negative charge regions.Conversely,the CCRs feature a typical tripolar charge structure.The dominant dipole charge structure in the TFR results in an increase in the negative charge field below the negative charge region with height,providing a necessary condition for successfully triggering negative TLFs.Furthermore,the horizontal extent of TLFs is positively correlated with their duration and charge transfer.Regions where TLF channels with larger charge transfers propagate tend to have greater maximum radar reflectivity but lower average radar reflectivity compared to regions with TLFs with smaller charge transfer.展开更多
The communication stations are more easily struck by lightning because of its special geographical position. We proved theoretically that communication station increased the frequency and intensity of lightning strike...The communication stations are more easily struck by lightning because of its special geographical position. We proved theoretically that communication station increased the frequency and intensity of lightning strike in its neighboring region, thereby causing the increasing of lightning disaster loss. As long as the emphasis is put on the correct understanding and reasonably taking measures including： draining, grounding, equipo- tential bonding and shielding, it can be completely ensured that building and equipment of communication base station and its neighboring region are safe.展开更多
Visualizing lightning location data is necessary in analyzing and researching lightning activity patterns.This article uses C#and the cross-platform.NET framework to develop a lightning location data analysis class li...Visualizing lightning location data is necessary in analyzing and researching lightning activity patterns.This article uses C#and the cross-platform.NET framework to develop a lightning location data analysis class library and the data-driven client to help lightning researchers improve work efficiency by avoiding repeated wheel invention.Lightning Location System Data Analyzer(LLSDA)is a suite of software tools that includes a.NET class library for software developers and a desktop application for end users.It supports a wide range of lightning location data formats,such as the University of Washington Global Lightning Location System(WWLLN)and Beijing Huayun Dongfang ADTD Lightning Location System data format,and maintains scalability.The class library can easily read,parse,and analyze lightning location data,and combined with third-party frameworks can realize grid analysis.The desktop application can be combined with MeteoInfo(a GIS open-source project)for secondary development.展开更多
By using the reported data of lightning disaster and the data of lightning monitoring network in Shandong Province since its establishment,the lightning activities and the disaster climate characteristics in Shandong ...By using the reported data of lightning disaster and the data of lightning monitoring network in Shandong Province since its establishment,the lightning activities and the disaster climate characteristics in Shandong Province were analyzed.The data were processed by lattice formulation,and the spatial and temporal distribution characteristics of positive and negative CG flashes were given.The parameter characteristics of positive and negative ground lightning and its relationship with the lightning disasters were analyzed.And the lightning parameter characteristics of lightning in major cities of Shandong Province were analyzed.展开更多
Activity 1 Think about the following questions and write down your answers before reading the text.1.What are some common factors that usually cause damage to trees when they are struck by lightning?2.How might the un...Activity 1 Think about the following questions and write down your answers before reading the text.1.What are some common factors that usually cause damage to trees when they are struck by lightning?2.How might the unique characteristics of a tree contribute to its ability to survive a lightning strike?展开更多
The protection effectiveness of traditional Lightning Strike Protection(LSP)for composite rotor blade of helicopter can be diminished due to the explosion risk in overlapping attachment under lightning strike,so a new...The protection effectiveness of traditional Lightning Strike Protection(LSP)for composite rotor blade of helicopter can be diminished due to the explosion risk in overlapping attachment under lightning strike,so a new protection method based on Air Breakdown and insulating adhesive layer(AB-LSP method)was designed to avoid it.In this study,a numerical method was developed to simulate the electrical breakdown,and verified by experiment results.Based on this method,a Finite Element Model(FEM)was established to investigate the effect of two factors(breakdown strength and initial ablation temperature of adhesive layer)on the LSP effectiveness.The results show that the breakdown strength impacts more to the ablation damage in composite than that of high-temperature resistance.Then,another FEM was established to predict the ablation damage by lightning strike in the AB-LSP method protected composite rotor blade.The mechanisms and potential key parameters(magnitude of lightning current,discharge channel location,adhesive layer thickness,and air gap width)that could affect the protection effectiveness were analyzed.The introduction of air breakdown changes the current conduction path and reduces explosion risk.After rational design,this method can offer effective lightning protection for composite helicopter rotor blade and other composite structures.展开更多
Based on the site investigation of a lightning stroke accident in a coal mine in Weiyuan County during a strong thunderstorm process on the night of August 10,2024,combined with the investigation data of the accident ...Based on the site investigation of a lightning stroke accident in a coal mine in Weiyuan County during a strong thunderstorm process on the night of August 10,2024,combined with the investigation data of the accident site,the causes of the lightning stroke accident were analyzed,and the corresponding rectification suggestions were put forward.展开更多
The Van Allen radiation belts are doughnut-shaped zones surrounding Earth, filled with highly energetic charged particles whose sources or loss mechanisms have been investigated for decades. As for the inner belt, cos...The Van Allen radiation belts are doughnut-shaped zones surrounding Earth, filled with highly energetic charged particles whose sources or loss mechanisms have been investigated for decades. As for the inner belt, cosmic ray albedo neutron decay(CRAND),radial diffusion, and local acceleration have been considered principal sources of electrons, whereas protons are predominantly from CRAND and solar protons. In this article, lightning-induced neutrons from Earth's upper atmosphere are suggested as a possible source of protons and electrons in the inner radiation belt. These terrestrial neutrons can contribute to the inner belt population by undergoing nuclear decay. Several approaches are proposed and discussed to evaluate the potential contribution of lightning-induced neutrons to the inner belt, including magnitude estimation, Monte Carlo simulations, and in situ observations. This article discusses some avenues of further study to determine the contribution of lightning-induced neutrons to the inner radiation belt.展开更多
In the past,the lightning strike risk assessment of wind farms mainly referred to the Lightning Protection Part 2:Risk Management(IEC 62305-2-2010)and the Lightning Protection of Wind Energy System(IEC 61400-24-2019)b...In the past,the lightning strike risk assessment of wind farms mainly referred to the Lightning Protection Part 2:Risk Management(IEC 62305-2-2010)and the Lightning Protection of Wind Energy System(IEC 61400-24-2019)based on protection angle method.In fact,the basic idea of the two is the same,that is,the source of the lightning fan is replaced by S1-S4 of the former lightning building with the latter ND-NDJ.According to the above method of wind farm evaluation,it has been proved that the practice can not achieve good results.Taking offshore wind farm as an example,this paper introduces a new method of establishing six evaluation indicators to determine the risk level according to the new technology and compliance principle of regional lightning protection(semi-circular method),which can be used for reference by wind farm technicians.展开更多
It is one of the most effective ways to use laboratory long air gap discharges for investigating the fundamental process involved in the lightning strike.During the 1960s and the 1970s,the electro-geometrical method(E...It is one of the most effective ways to use laboratory long air gap discharges for investigating the fundamental process involved in the lightning strike.During the 1960s and the 1970s,the electro-geometrical method(EGM)and the rolling sphere method were developed base on the breakdowncharacteristics of negative long spark discharges,which have been widely used to design the lightning shielding system of transmission lines and structures.In recent years,the scale of the power facilities is increased dramatically with the rising of power grid's voltage level.The impact of upward connecting leader launched from those large-scale facilities on the lightning shielding performance cannot be neglected;otherwise,the validity of the EGM in the lightning shielding design of EHV and UHV transmission lines will be challenged.The research evolutions on the lightning striking distance,the lightning simulation experiments and the positive upward connecting leader process by using laboratory long sparks are reviewed and discussed in this paper.展开更多
At present, lightning is one of the 10 natural disasters, and it is also the top environmental factor of power interruption. It often causes huge losses to the electric system. The Wuhan High Voltage Institute of the ...At present, lightning is one of the 10 natural disasters, and it is also the top environmental factor of power interruption. It often causes huge losses to the electric system. The Wuhan High Voltage Institute of the State Grid Corporation of China and Huazhong University of Science and Technology have been researching and developing lightning location systems （LLSs） since the late 1980s. In the mid-1990s, a lightning detection network was created in 29 provinces and cities in China. It is primarily applied to rapidly find lightning accidents, which greatly reduces power interruption. Also, it ensures high efficiency and safe operation of the electricity system. Remarkable benefit is achieved. China＇s LLS went through an ＂orientation positioning - time difference positioning - integrated positioning＂ development process. The positioning precision, detection efficiency, degree of automation, practicability and applied range are improved. Also, a lightning information system plan of the national network has been implemented, which services the whole society.展开更多
Lightning-generated nitrogen oxides(LNO_(x))have a major influence on the atmosphere and global climate change.Therefore,it is of great importance to obtain a more accurate estimation of LNO_(x).The aim of this study ...Lightning-generated nitrogen oxides(LNO_(x))have a major influence on the atmosphere and global climate change.Therefore,it is of great importance to obtain a more accurate estimation of LNO_(x).The aim of this study is to provide a reference for the accurate estimation of the total LNO_(x) in the mainland of China based on cloud-to-ground lightning(CG)location data from 2014 to 2018.The energy of each CG flash was based on the number of return strokes per CG flash,the peak current of each return stroke,and the assumed CG breakdown voltage.The energy of intracloud lightning(IC)was based on the estimated frequencies of IC and the assumed energy of each IC flash.Combining the energy of lightning and the number of nitric oxide(NO)molecules produced by unit energy(ρno),the total LNO_(x) production in the mainland of China was determined.The LNO_(x) in the mainland of China estimated in this study is in the range(0.157-0.321)×10^(9) kg per year[Tg(N)yr-1],which is on the high end of other scholars’works.Negative cloud-to-ground lightning(NCG)flashes produce the most moles of NO_(x),while positive cloud-to-ground lightning(PCG)flashes produce the least total moles of NO_(x).The breakdown voltage of PCG is greater than that of IC or NCG,while the latter has a greater output of LNO_(x).展开更多
With the development of the time and the progress of economy,great changes have taken place in the environment.In recent years,it is common to see bad weather,such as hurricane,drought,lightning and so on.The emergenc...With the development of the time and the progress of economy,great changes have taken place in the environment.In recent years,it is common to see bad weather,such as hurricane,drought,lightning and so on.The emergence of these weather has the greatest impact on farmers and crops,especially the lightning weather,not only that,but also sometimes cause personal injury.In face of the frequent occurrence of bad weather in recent years and its harm and threat to China's agriculture,rural areas,personnel,etc.,the author makes a detailed study on the causes of rural lightning weather,analyzes the lightning protection measures in rural areas and their shortcomings,and summarizes the relevant improvement measures.展开更多
The climate impact assessment and monthly and annual reports of surface meteorological observation of cities and counties were reviewed,and there were no records of lightning disasters in Shaoyang from 1978 to 2000.Si...The climate impact assessment and monthly and annual reports of surface meteorological observation of cities and counties were reviewed,and there were no records of lightning disasters in Shaoyang from 1978 to 2000.Since 2001,there have been few records of lightning disasters,with only about 10 times in various regions.In this paper,a total of 143 investigation reports on lightning accidents since 2002 were collected,and statistical analysis was conducted based on the loss,location of occurrence,damaged industries,and social impact.In particular,the temporal and spatial distribution characteristics of lightning in Shaoyang area have been clearly understood,and the main characteristics and laws of lightning accidents in Shaoyang area were revealed.The results showed that the most lightning accidents occurred in June,and no lightning accidents occurred in December.Dongkou,Longhui,and Shaoyang urban areas were the lightning prone areas,and the impact of lightning on agriculture was the largest,followed by commerce.The prevention countermeasures of lightning disasters were proposed to provide reference for disaster prevention and reduction.展开更多
Based on the cloud-to-ground（ CG） lightning flashes data and other related data from 1999 to 2016,the lightning risk zoning of Meizhou was conducted by using the analytic hierarchy process（ AHP） model. The model c...Based on the cloud-to-ground（ CG） lightning flashes data and other related data from 1999 to 2016,the lightning risk zoning of Meizhou was conducted by using the analytic hierarchy process（ AHP） model. The model considered the natural conditions,social economic conditions and other factors,and the main assessment factors were selected,containing ＂ flash density,lightning current intensity,annual thunderstorm days,lightning disaster frequency,construction area per capita and GDP per capita＂,in order to establish the evaluation model,and divide the level of risk. The results showed that the lightning risk in Meizhou area roughly had the trend of ＂ center higher than all-around,the south higher than the north,the west higher than the east＂. High-risk area was in the most region of Meijiang District and central region of Meixian District,and Wuhua County was next high-risk area. Xingning City and Fengshun County were medium risk areas,most of the other were low risk area. The result of regionalization was consistent with the actual situation,and the evaluation method was scientific and effective. Through the analysis of the lightning risk zoning,this paper could provide a scientific basis for the lightning protection and disaster reduction in the region in the future.展开更多
From January 2020 to December 2021,Ulanqab Meteorological Bureau of Inner Mongolia used VLF/LF lightning locator to carry out three-dimensional lightning monitoring in Ulanqab City,and compared with ADTD lightning loc...From January 2020 to December 2021,Ulanqab Meteorological Bureau of Inner Mongolia used VLF/LF lightning locator to carry out three-dimensional lightning monitoring in Ulanqab City,and compared with ADTD lightning location data in the same period.The results show that both VLF/LF lightning locator and ADTD lightning locator had excellent monitoring ability for lightning during flood season in Ulanqab.VLF/LF lightning locator was slightly superior to ADTD lightning locator in observation accuracy,the observation ability of low-current cloud-to-ground lightning,intracloud lightning observation and so on.There were obvious temporal and spatial characteristics of cloud-to-ground lightning during flood season in Ulanqab,and there was a certain correlation between the areas where lightning appeared frequently and surface water.Intracloud lightning was mainly concentrated at a height of 1-7 km.Negative cloud-to-ground lightning accounted for about 75%of total cloud-to-ground lightning,and negative intracloud lightning accounted for 39%of total intracloud lightning.展开更多
Regional lightning protection is a complete theoretical system,mainly including:lightning interception technology(LIPT),lightning strong electromagnetic pulse high-energy absorption technology(MSPD),and regional light...Regional lightning protection is a complete theoretical system,mainly including:lightning interception technology(LIPT),lightning strong electromagnetic pulse high-energy absorption technology(MSPD),and regional lightning activity law analysis technology(RLLA).Lightning interception technology uses dispersive waveguide resonant cavity technology to achieve the functions of 46.55 m longer than upward leader of ordinary lightning rod,significantly reducing lightning strike point current by 40%,optimizing space electromagnetic field environment,and effectively intercepting overhead and side lightning strikes,and overcome the limitations of traditional lightning rod.The lightning strong electromagnetic pulse high-energy absorption technology uses distributed parameter balance technology,special disconnector for short circuit current,and parity pairing technology to achieve stronger surge absorption capacity than traditional single pulse SPD and international advanced technical indicators such as timely breaking under power frequency short circuit current,and good energy and time coordination.The analysis technology of regional lightning activity laws accurately identifies lightning strike points through comprehensive analysis of regional lightning activity laws,physical parameters of ion clouds,and the impact on ground electric fields.The three core technology systems complement each other,achieving all-round protection against direct lightning strike and lightning electromagnetic pulse.Several projects achieved zero lightning damage,effectively ensuring the safety of buildings and electronic and electrical equipment in the protected area.展开更多
Based on the data of cloud-to-ground lightning obtained by the lightning detection system in Hongya County during 2011-2015,the parameters of lightning current intensity and steepness in Hongya County were analyzed,an...Based on the data of cloud-to-ground lightning obtained by the lightning detection system in Hongya County during 2011-2015,the parameters of lightning current intensity and steepness in Hongya County were analyzed,and the lightning parameters and the annual average density of lightning stroke to earth were discussed in combination with the Design Code for Protection of Structures against Lightning(GB 50057-2010),so as to provide scientific guidance for lightning disaster prevention in Hongya County.展开更多
文摘Currently,the number of lightning casualties and casualty rates have significantly reduced in developed countries,but there has been no significant reduction in developing countries.On the one hand,this is due to the high frequency of lightning;on the other hand,the vulnerability of people in developing countries is also an influencing factor.Through case analysis and summary,this paper expounds on lightning injury s mechanism and clinical manifestations.It points out that lightning injury is mainly related to heart problems and the impact on the nervous system,rather than burns,which usually cause fewer consequences.Medical treatment needs to pay attention to the order and principles of treatment.Implementing CPR and auxiliary AED is the most effective way to save lives.Attention should be paid to the practical and effective treatment and nursing of lightning stroke sequelae.Finally,combined with the situation of lightning casualties in China,the existing problems are put forward during the process of early treatment,post-hospital treatment,and nursing observation,which provides an objective basis for the cognition of the scientific nature of the lightning injury.
基金funded by the Natural Science Foundation of China(Grant No.U2342215)Key Laboratory of South China Sea Meteorological Disaster Prevention and Mitigation of Hainan Province(Grant No.SCSF202302)。
文摘This study utilizes data from a 3D lightning location system,polarimetric radar,and current measurements from channels of triggered lightning flashes(TLFs)to analyze the structural characteristics of the parent thunderstorms associated with negative TLFs in South China.The triggered-flash region(TFR)displays distinct stratiform cloud characteristics,including lower radar reflectivity heights and a predominance of ice crystals and dry snow above the 0℃ layer.In contrast,the thunderstorm convection core region(CCR)tends to have more graupel particles in the mixed-phase layers and exhibits an ice-water content peak approximately 3.4 times that of the TFR.The charge regions involved in discharges in TFRs exhibit a dipolar charge structure,with the-5℃ layer roughly dividing the upper positive and lower negative charge regions.Conversely,the CCRs feature a typical tripolar charge structure.The dominant dipole charge structure in the TFR results in an increase in the negative charge field below the negative charge region with height,providing a necessary condition for successfully triggering negative TLFs.Furthermore,the horizontal extent of TLFs is positively correlated with their duration and charge transfer.Regions where TLF channels with larger charge transfers propagate tend to have greater maximum radar reflectivity but lower average radar reflectivity compared to regions with TLFs with smaller charge transfer.
文摘The communication stations are more easily struck by lightning because of its special geographical position. We proved theoretically that communication station increased the frequency and intensity of lightning strike in its neighboring region, thereby causing the increasing of lightning disaster loss. As long as the emphasis is put on the correct understanding and reasonably taking measures including： draining, grounding, equipo- tential bonding and shielding, it can be completely ensured that building and equipment of communication base station and its neighboring region are safe.
文摘Visualizing lightning location data is necessary in analyzing and researching lightning activity patterns.This article uses C#and the cross-platform.NET framework to develop a lightning location data analysis class library and the data-driven client to help lightning researchers improve work efficiency by avoiding repeated wheel invention.Lightning Location System Data Analyzer(LLSDA)is a suite of software tools that includes a.NET class library for software developers and a desktop application for end users.It supports a wide range of lightning location data formats,such as the University of Washington Global Lightning Location System(WWLLN)and Beijing Huayun Dongfang ADTD Lightning Location System data format,and maintains scalability.The class library can easily read,parse,and analyze lightning location data,and combined with third-party frameworks can realize grid analysis.The desktop application can be combined with MeteoInfo(a GIS open-source project)for secondary development.
基金Supported by Shandong Meteorology Bureau (2005sdqxj01)Shandong Metrological Observatory (Preliminary Study on Forecast of Lightning Disasters in Shandong Province)
文摘By using the reported data of lightning disaster and the data of lightning monitoring network in Shandong Province since its establishment,the lightning activities and the disaster climate characteristics in Shandong Province were analyzed.The data were processed by lattice formulation,and the spatial and temporal distribution characteristics of positive and negative CG flashes were given.The parameter characteristics of positive and negative ground lightning and its relationship with the lightning disasters were analyzed.And the lightning parameter characteristics of lightning in major cities of Shandong Province were analyzed.
文摘Activity 1 Think about the following questions and write down your answers before reading the text.1.What are some common factors that usually cause damage to trees when they are struck by lightning?2.How might the unique characteristics of a tree contribute to its ability to survive a lightning strike?
文摘The protection effectiveness of traditional Lightning Strike Protection(LSP)for composite rotor blade of helicopter can be diminished due to the explosion risk in overlapping attachment under lightning strike,so a new protection method based on Air Breakdown and insulating adhesive layer(AB-LSP method)was designed to avoid it.In this study,a numerical method was developed to simulate the electrical breakdown,and verified by experiment results.Based on this method,a Finite Element Model(FEM)was established to investigate the effect of two factors(breakdown strength and initial ablation temperature of adhesive layer)on the LSP effectiveness.The results show that the breakdown strength impacts more to the ablation damage in composite than that of high-temperature resistance.Then,another FEM was established to predict the ablation damage by lightning strike in the AB-LSP method protected composite rotor blade.The mechanisms and potential key parameters(magnitude of lightning current,discharge channel location,adhesive layer thickness,and air gap width)that could affect the protection effectiveness were analyzed.The introduction of air breakdown changes the current conduction path and reduces explosion risk.After rational design,this method can offer effective lightning protection for composite helicopter rotor blade and other composite structures.
文摘Based on the site investigation of a lightning stroke accident in a coal mine in Weiyuan County during a strong thunderstorm process on the night of August 10,2024,combined with the investigation data of the accident site,the causes of the lightning stroke accident were analyzed,and the corresponding rectification suggestions were put forward.
基金supported by the National Natural Science Foundation of China (No. 42225405 and No. 42350710200)。
文摘The Van Allen radiation belts are doughnut-shaped zones surrounding Earth, filled with highly energetic charged particles whose sources or loss mechanisms have been investigated for decades. As for the inner belt, cosmic ray albedo neutron decay(CRAND),radial diffusion, and local acceleration have been considered principal sources of electrons, whereas protons are predominantly from CRAND and solar protons. In this article, lightning-induced neutrons from Earth's upper atmosphere are suggested as a possible source of protons and electrons in the inner radiation belt. These terrestrial neutrons can contribute to the inner belt population by undergoing nuclear decay. Several approaches are proposed and discussed to evaluate the potential contribution of lightning-induced neutrons to the inner belt, including magnitude estimation, Monte Carlo simulations, and in situ observations. This article discusses some avenues of further study to determine the contribution of lightning-induced neutrons to the inner radiation belt.
基金Supported by Research on Key Technologies of Lightning Intelligent Protection System for Guangdong Energy Hehe Sea Wind Farm(SFC/QZW-ZX-XF-24-020).
文摘In the past,the lightning strike risk assessment of wind farms mainly referred to the Lightning Protection Part 2:Risk Management(IEC 62305-2-2010)and the Lightning Protection of Wind Energy System(IEC 61400-24-2019)based on protection angle method.In fact,the basic idea of the two is the same,that is,the source of the lightning fan is replaced by S1-S4 of the former lightning building with the latter ND-NDJ.According to the above method of wind farm evaluation,it has been proved that the practice can not achieve good results.Taking offshore wind farm as an example,this paper introduces a new method of establishing six evaluation indicators to determine the risk level according to the new technology and compliance principle of regional lightning protection(semi-circular method),which can be used for reference by wind farm technicians.
文摘It is one of the most effective ways to use laboratory long air gap discharges for investigating the fundamental process involved in the lightning strike.During the 1960s and the 1970s,the electro-geometrical method(EGM)and the rolling sphere method were developed base on the breakdowncharacteristics of negative long spark discharges,which have been widely used to design the lightning shielding system of transmission lines and structures.In recent years,the scale of the power facilities is increased dramatically with the rising of power grid's voltage level.The impact of upward connecting leader launched from those large-scale facilities on the lightning shielding performance cannot be neglected;otherwise,the validity of the EGM in the lightning shielding design of EHV and UHV transmission lines will be challenged.The research evolutions on the lightning striking distance,the lightning simulation experiments and the positive upward connecting leader process by using laboratory long sparks are reviewed and discussed in this paper.
文摘At present, lightning is one of the 10 natural disasters, and it is also the top environmental factor of power interruption. It often causes huge losses to the electric system. The Wuhan High Voltage Institute of the State Grid Corporation of China and Huazhong University of Science and Technology have been researching and developing lightning location systems （LLSs） since the late 1980s. In the mid-1990s, a lightning detection network was created in 29 provinces and cities in China. It is primarily applied to rapidly find lightning accidents, which greatly reduces power interruption. Also, it ensures high efficiency and safe operation of the electricity system. Remarkable benefit is achieved. China＇s LLS went through an ＂orientation positioning - time difference positioning - integrated positioning＂ development process. The positioning precision, detection efficiency, degree of automation, practicability and applied range are improved. Also, a lightning information system plan of the national network has been implemented, which services the whole society.
基金supported by the National Natural Science Foundation of China (Grant Nos. 91537209 and 91644224)
文摘Lightning-generated nitrogen oxides(LNO_(x))have a major influence on the atmosphere and global climate change.Therefore,it is of great importance to obtain a more accurate estimation of LNO_(x).The aim of this study is to provide a reference for the accurate estimation of the total LNO_(x) in the mainland of China based on cloud-to-ground lightning(CG)location data from 2014 to 2018.The energy of each CG flash was based on the number of return strokes per CG flash,the peak current of each return stroke,and the assumed CG breakdown voltage.The energy of intracloud lightning(IC)was based on the estimated frequencies of IC and the assumed energy of each IC flash.Combining the energy of lightning and the number of nitric oxide(NO)molecules produced by unit energy(ρno),the total LNO_(x) production in the mainland of China was determined.The LNO_(x) in the mainland of China estimated in this study is in the range(0.157-0.321)×10^(9) kg per year[Tg(N)yr-1],which is on the high end of other scholars’works.Negative cloud-to-ground lightning(NCG)flashes produce the most moles of NO_(x),while positive cloud-to-ground lightning(PCG)flashes produce the least total moles of NO_(x).The breakdown voltage of PCG is greater than that of IC or NCG,while the latter has a greater output of LNO_(x).
文摘With the development of the time and the progress of economy,great changes have taken place in the environment.In recent years,it is common to see bad weather,such as hurricane,drought,lightning and so on.The emergence of these weather has the greatest impact on farmers and crops,especially the lightning weather,not only that,but also sometimes cause personal injury.In face of the frequent occurrence of bad weather in recent years and its harm and threat to China's agriculture,rural areas,personnel,etc.,the author makes a detailed study on the causes of rural lightning weather,analyzes the lightning protection measures in rural areas and their shortcomings,and summarizes the relevant improvement measures.
文摘The climate impact assessment and monthly and annual reports of surface meteorological observation of cities and counties were reviewed,and there were no records of lightning disasters in Shaoyang from 1978 to 2000.Since 2001,there have been few records of lightning disasters,with only about 10 times in various regions.In this paper,a total of 143 investigation reports on lightning accidents since 2002 were collected,and statistical analysis was conducted based on the loss,location of occurrence,damaged industries,and social impact.In particular,the temporal and spatial distribution characteristics of lightning in Shaoyang area have been clearly understood,and the main characteristics and laws of lightning accidents in Shaoyang area were revealed.The results showed that the most lightning accidents occurred in June,and no lightning accidents occurred in December.Dongkou,Longhui,and Shaoyang urban areas were the lightning prone areas,and the impact of lightning on agriculture was the largest,followed by commerce.The prevention countermeasures of lightning disasters were proposed to provide reference for disaster prevention and reduction.
基金Supported by the Science and Technology Plan Project in Meizhou Region(2016B204)
文摘Based on the cloud-to-ground（ CG） lightning flashes data and other related data from 1999 to 2016,the lightning risk zoning of Meizhou was conducted by using the analytic hierarchy process（ AHP） model. The model considered the natural conditions,social economic conditions and other factors,and the main assessment factors were selected,containing ＂ flash density,lightning current intensity,annual thunderstorm days,lightning disaster frequency,construction area per capita and GDP per capita＂,in order to establish the evaluation model,and divide the level of risk. The results showed that the lightning risk in Meizhou area roughly had the trend of ＂ center higher than all-around,the south higher than the north,the west higher than the east＂. High-risk area was in the most region of Meijiang District and central region of Meixian District,and Wuhua County was next high-risk area. Xingning City and Fengshun County were medium risk areas,most of the other were low risk area. The result of regionalization was consistent with the actual situation,and the evaluation method was scientific and effective. Through the analysis of the lightning risk zoning,this paper could provide a scientific basis for the lightning protection and disaster reduction in the region in the future.
文摘From January 2020 to December 2021,Ulanqab Meteorological Bureau of Inner Mongolia used VLF/LF lightning locator to carry out three-dimensional lightning monitoring in Ulanqab City,and compared with ADTD lightning location data in the same period.The results show that both VLF/LF lightning locator and ADTD lightning locator had excellent monitoring ability for lightning during flood season in Ulanqab.VLF/LF lightning locator was slightly superior to ADTD lightning locator in observation accuracy,the observation ability of low-current cloud-to-ground lightning,intracloud lightning observation and so on.There were obvious temporal and spatial characteristics of cloud-to-ground lightning during flood season in Ulanqab,and there was a certain correlation between the areas where lightning appeared frequently and surface water.Intracloud lightning was mainly concentrated at a height of 1-7 km.Negative cloud-to-ground lightning accounted for about 75%of total cloud-to-ground lightning,and negative intracloud lightning accounted for 39%of total intracloud lightning.
基金Supported by Lightning Multi-pulse Intelligent Monitoring System Optimization Technology Project of Guangdong Yuedian Dianbai Hot Water Wind Farm(SFC/DBW-Z-FW-23-006).
文摘Regional lightning protection is a complete theoretical system,mainly including:lightning interception technology(LIPT),lightning strong electromagnetic pulse high-energy absorption technology(MSPD),and regional lightning activity law analysis technology(RLLA).Lightning interception technology uses dispersive waveguide resonant cavity technology to achieve the functions of 46.55 m longer than upward leader of ordinary lightning rod,significantly reducing lightning strike point current by 40%,optimizing space electromagnetic field environment,and effectively intercepting overhead and side lightning strikes,and overcome the limitations of traditional lightning rod.The lightning strong electromagnetic pulse high-energy absorption technology uses distributed parameter balance technology,special disconnector for short circuit current,and parity pairing technology to achieve stronger surge absorption capacity than traditional single pulse SPD and international advanced technical indicators such as timely breaking under power frequency short circuit current,and good energy and time coordination.The analysis technology of regional lightning activity laws accurately identifies lightning strike points through comprehensive analysis of regional lightning activity laws,physical parameters of ion clouds,and the impact on ground electric fields.The three core technology systems complement each other,achieving all-round protection against direct lightning strike and lightning electromagnetic pulse.Several projects achieved zero lightning damage,effectively ensuring the safety of buildings and electronic and electrical equipment in the protected area.
文摘Based on the data of cloud-to-ground lightning obtained by the lightning detection system in Hongya County during 2011-2015,the parameters of lightning current intensity and steepness in Hongya County were analyzed,and the lightning parameters and the annual average density of lightning stroke to earth were discussed in combination with the Design Code for Protection of Structures against Lightning(GB 50057-2010),so as to provide scientific guidance for lightning disaster prevention in Hongya County.
