To better improve the electrical safety of buildings and fulfill the role of lightning protection and grounding,this article combines cases and discusses seven aspects of lightning protection devices’construction tec...To better improve the electrical safety of buildings and fulfill the role of lightning protection and grounding,this article combines cases and discusses seven aspects of lightning protection devices’construction technology.These aspects include the lightning protection classification of buildings,air terminals,down conductors,grounding devices,division of lightning protection zones,and lightning electromagnetic pulse shielding.Through the introduction of this article,readers can gain a comprehensive understanding of the application and value of lightning protection grounding construction technology in building electrical installation projects.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
The lightning protection design of "Feilongzaitian" roller coaster of Fangte in Zigong was discussed, and the lightning protection measures of "Feilongzaitian" roller coaster were analyzed from the...The lightning protection design of "Feilongzaitian" roller coaster of Fangte in Zigong was discussed, and the lightning protection measures of "Feilongzaitian" roller coaster were analyzed from the aspects of direct lightning protection, grounding and lightning electromagnetic impulse protection.展开更多
The role played by equipotential connection in lightning protection was summarized in terms of lightning protection,static electricity,electromagnetic shielding,protection from electric shocks,and earth fault protecti...The role played by equipotential connection in lightning protection was summarized in terms of lightning protection,static electricity,electromagnetic shielding,protection from electric shocks,and earth fault protection.In addition,drawbacks of independent grounding and common grounding were concluded.According to standards and researches,such as Building Lightning Protection Design Standard （GB50057-2010）,further demands and rules of equipotential connection in lightning protection engineering were proposed,providing references for lightning prevention design,construction and examination by related scientific workers and staffs.展开更多
DCS （distributed control system） plays a decisive role in the overall operation of a nuclear power plant. If DCS fails, it will seriously affect the normal production of nuclear power plant, causing great losses. So...DCS （distributed control system） plays a decisive role in the overall operation of a nuclear power plant. If DCS fails, it will seriously affect the normal production of nuclear power plant, causing great losses. So it is very important to take perfect lightning protection measures on DCS of the nuclear power plant. In this paper, according to the actual situation of DCS in a nuclear power plant, by controlling lightning point, securely booting lightning into the ground network, improving low-resistance ground network, eliminating ground loops, determining the safety space, surge protection of power and signal, a set of complete lightning protection design scheme was systematically put forward. Some specific lightning protection measures were highlighted, such as the DCS grounding, equipotential bonds and shields, and some specific considerations were put forward. All of these could offer reference in the practical application.展开更多
Via database technology, a perfect lightning protection integrated service work platform is established, thereby realizing paperless data management of routine business.
Due to its large and metallic structure, large recreation facility is easy to be struck by lightning. Meanwhile, the lightning strike conse- quences are serious, including threat to the life and property safety of tou...Due to its large and metallic structure, large recreation facility is easy to be struck by lightning. Meanwhile, the lightning strike conse- quences are serious, including threat to the life and property safety of tourists, great impact on society and bad effect on the development of tourism. As a result, lightning protection of recreation facility is particularly important. Taking the Ferris wheel of Zijin Park as an example, its light- ning risk and structural characteristics were analyzed to make reasonable solving scheme. Through the study about lightning risks of recreational fa- cilities with different structures and geographical positions, the lightning protection differences between recreational facilities and the general lightning protection scheme were summarized.展开更多
This paper is devoted to the study of the most suitable protocols needed to verify the lightning protection and ground resistance quality in a large-scale scientific facility located on a site with high risk of lightn...This paper is devoted to the study of the most suitable protocols needed to verify the lightning protection and ground resistance quality in a large-scale scientific facility located on a site with high risk of lightning strikes. We illustrate this work by reviewing a case study: the largest telescopes of the Northern Hemisphere Cherenkov Telescope Array, CTA-N. This array hosts sensitive and high-speed optoelectronics instrumentation and sits on a clear, free from obstacle terrain at around 2400 m above sea level. The site offers a top-quality sky but also features challenging conditions for a lightning protection system: the terrain is volcanic and has electrical resistivities well above 1 kOhm·m. In addition, the environment often exhibits humidities well below 5%, and strong winds pose challenging conditions. On the other hand, the </span><span style="font-family:Verdana;">high complexity of a Cherenkov telescope structure does not allow a straightforward</span><span style="font-family:Verdana;"> application of lightning protection standards. We describe here how the risk assessment of direct strike impacts was made and how contact voltages and ground system were both tested. Finite Element Simulation (COMSOL Multiphysics) has been used to estimate the current flowing through the parts of the earthing system designed for the telescopes in the case of a direct strike impact. This work is intended to provide assistance to scientists and managers involved in the construction of scientific installations, particularly those in charge of defining verifiable reliability and safety requirements for lightning protection.展开更多
An electronic information system is composed of multiple groups of components. With the improvement of technology, its accuracy is getting higher and higher. The voltage during normal operation is only a few volts, an...An electronic information system is composed of multiple groups of components. With the improvement of technology, its accuracy is getting higher and higher. The voltage during normal operation is only a few volts, and the information current is only microamp, so the withstand voltage to lightning electromagnetic pulse is extremely low. In this paper, the negative impact of lightning and static electricity on the computer room of an electronic information system was analyzed firstly, and then the design for the lightning protection of the computer room was discussed.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
Based on Internet technology,modern wireless communication technology and new sensor technology,an intelligent protection and monitoring system of lightning disaster was established to collect lightning current(lightn...Based on Internet technology,modern wireless communication technology and new sensor technology,an intelligent protection and monitoring system of lightning disaster was established to collect lightning current(lightning intensity,frequency and time),induced lightning current and leakage current of surge protector(SPD),earthing resistance,working voltage,temperature and humidity in the lightning environment and other data in real time.Through the online analysis of visual data and automatic alarm beyond the preset value of cloud platform,it can realize the intelligent online monitoring and management of lightning protection devices,providing scientific and reliable lightning protection technical support for lightning protection and disaster reduction,and ensuring the smooth development and efficient management of lightning protection safety work.展开更多
Under the influence of special terrain and climatic conditions,lightning weather in Ulanqab City is more frequent from June to August,and lightning disaster has become one of the important tasks of disaster prevention...Under the influence of special terrain and climatic conditions,lightning weather in Ulanqab City is more frequent from June to August,and lightning disaster has become one of the important tasks of disaster prevention and mitigation.In this paper,based on the characteristics of lightning weather in Ulanqab City,the impact of lightning disaster on the city was analyzed,and lightning protection measures,such as strengthening supervision of lightning protection safety,establishing a long-term lightning protection mechanism,doing a good job in lightning protection construction and detection in key places,and further improving public awareness of lightning protection,were put forward to reduce and avoid urban lightning disasters as much as possible and ensure urban safety.展开更多
The rail weighbridge system of a railway freight station is introduced firstly, and then the earthing method for protection of the rail weighbridge system against lightning based on YLG-60 equipotential bonding surge ...The rail weighbridge system of a railway freight station is introduced firstly, and then the earthing method for protection of the rail weighbridge system against lightning based on YLG-60 equipotential bonding surge protection device is shown.展开更多
The non-metallic lightning strike protection film covering carbon fiber reinforced polymers(NM-LSP covering CFRP)can reduce the weight and thus the fuel consumption of aircraft by replacing the traditional lightning s...The non-metallic lightning strike protection film covering carbon fiber reinforced polymers(NM-LSP covering CFRP)can reduce the weight and thus the fuel consumption of aircraft by replacing the traditional lightning strike protection(LSP)materials.In the present study,in order to study the environmental influence of utilizing NM-LSP covering CFRP in an aircraft elevator,a new elevator was designed and manufactured,replacing the aluminium net and glass fiber reinforced polymers(GFRP)with NM-LSP covering CFRP,with the same mechanical and LSP abilities.A comparative life cycle assessment was conducted between the two kinds of aircraft elevators,including material extraction,transportation,elevator manufacturing phase,service phase,and end-of-life procedures.Additionally,the environmental impacts of producing two LSP materials were compared by considering the environmental effects of different buy-to-fly ratios and recycling strategies on the production of aluminium net.The analysis indicates that the new elevator achieved reduction for all the environmental impact categories used,such as human toxicity potential and marine aquatic ecotoxicity potential(3.83%and 3.20%reduction).Furthermore,it is found that the service phase makes the greatest contribution to the environmental impact of the elevators under investigation.When recycling is excluded,NM-LSP covering CFRP is more environmentally friendly than the traditional material.At the same time,CFRP prepreg and electricity from the production of NM-LSP covering CFRP contribute to a higher environmental impact compared to the NM-LSP film.From the sensitivity analysis,it is believed that NM-LSP covering CFRP can reduce environmental impact compared with traditional LSP materials.展开更多
Different types of lightning air terminals have been designed over the years.Concern regarding the effect of different types of air terminals,especially the early streamer emission(ESE)-type,remains controversial.This...Different types of lightning air terminals have been designed over the years.Concern regarding the effect of different types of air terminals,especially the early streamer emission(ESE)-type,remains controversial.This paper describes the discharge characteristics of different types of air terminals,two of which are quite similar to the ESE-type dynasphere,and concludes that the tested non-standard air terminals have discharge characteristics similar to those of Franklin rods and that their lightning protection performance should be similar.展开更多
In recent years,several failures of double circuit transmission line on the same tower due to lightning were happened in Beijing power grid.Although it can be reclosed successful,the lightning strike caused a grave th...In recent years,several failures of double circuit transmission line on the same tower due to lightning were happened in Beijing power grid.Although it can be reclosed successful,the lightning strike caused a grave threat to the power grid security.The cause of the accident and the accident process were studied for the sake of further understanding of the impact of lightning on power grid.As an example,110 kV double circuit transmission line(Xilong-line) was analyzed.At first,the system topology was given.Through the analysis on relay protection actions and the fault recorder data,over voltage on the insulator strings was calculated.Based on the analysis and the calculation,accident cause and the process were presented respectively.Secondly,it comes to the conclusion that the lightning failure was caused by counterattack.The wave of the lightning over voltage would spread to the not grounded neutral point of the transformers,and make the neutral protective gap breakdown,then cause freewheeling with the frequency of 50 Hz.As results of the relay protection,the double circuit transmission line all tripped out.Finally,the causes of the accident were proposed that included terrain features,large corner towers,strong thunderstorm weather and poor grounded contact of the tower.展开更多
Taking a lightning accident of one unit as clue,weather characteristics and radar echo of lightning disaster occurrence were firstly checked, cause of lightning strike was analyzed,and focus and method of lightning pr...Taking a lightning accident of one unit as clue,weather characteristics and radar echo of lightning disaster occurrence were firstly checked, cause of lightning strike was analyzed,and focus and method of lightning protection in the units were summarized,which was beneficial to reducing loss and risk caused by lightning.展开更多
The latest research shows that the ions generated by the corona discharge of lightning rod have dual functions of attracting and shielding lightning discharge. After the lightning rod is installed at a certain height ...The latest research shows that the ions generated by the corona discharge of lightning rod have dual functions of attracting and shielding lightning discharge. After the lightning rod is installed at a certain height on the ground,the lightning rod tip reaches the corona threshold to ionize the surrounding air and generate positive and negative ions under the action of the electric field at the end of the lightning downward leader. Constrained by Coulomb’s Law,its positive ions( opposite charges attract each other) form an upward leader( streamer),which moves towards the end of the lightning downward leader and is connected to the downward leader,establishing a discharge channel to attract lightning to the needle tip and discharge the current to the ground,and playing a role in attracting lightning. Its negative ions are repelled by the electric field at the end of the lightning downward leader( repelled by isotropic charges) and influenced by the wind,and diffuse in the downwind area to form an ion cloud,inhibiting the growth of corona at the tip of ground objects,and playing a role in shielding lightning. In this paper,Franklin’s understanding of the role of lightning rod and Yang Shaojie’s new definition of the working principle of lightning rod are briefly introduced. The formation mechanism,distribution characteristics,shielding effect,and impact on lightning strike point distribution of ion clouds are analyzed. Additionally,the important role of shielding effects of ion clouds in regional lightning protection is introduced,which provides a theoretical basis for the correct understanding and use of lightning rod.展开更多
文摘To better improve the electrical safety of buildings and fulfill the role of lightning protection and grounding,this article combines cases and discusses seven aspects of lightning protection devices’construction technology.These aspects include the lightning protection classification of buildings,air terminals,down conductors,grounding devices,division of lightning protection zones,and lightning electromagnetic pulse shielding.Through the introduction of this article,readers can gain a comprehensive understanding of the application and value of lightning protection grounding construction technology in building electrical installation projects.
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The lightning protection design of "Feilongzaitian" roller coaster of Fangte in Zigong was discussed, and the lightning protection measures of "Feilongzaitian" roller coaster were analyzed from the aspects of direct lightning protection, grounding and lightning electromagnetic impulse protection.
文摘The role played by equipotential connection in lightning protection was summarized in terms of lightning protection,static electricity,electromagnetic shielding,protection from electric shocks,and earth fault protection.In addition,drawbacks of independent grounding and common grounding were concluded.According to standards and researches,such as Building Lightning Protection Design Standard （GB50057-2010）,further demands and rules of equipotential connection in lightning protection engineering were proposed,providing references for lightning prevention design,construction and examination by related scientific workers and staffs.
基金Research Fund for Youth in Jiangsu Provincial Meteorological Bureau,China(Q201007)
文摘DCS （distributed control system） plays a decisive role in the overall operation of a nuclear power plant. If DCS fails, it will seriously affect the normal production of nuclear power plant, causing great losses. So it is very important to take perfect lightning protection measures on DCS of the nuclear power plant. In this paper, according to the actual situation of DCS in a nuclear power plant, by controlling lightning point, securely booting lightning into the ground network, improving low-resistance ground network, eliminating ground loops, determining the safety space, surge protection of power and signal, a set of complete lightning protection design scheme was systematically put forward. Some specific lightning protection measures were highlighted, such as the DCS grounding, equipotential bonds and shields, and some specific considerations were put forward. All of these could offer reference in the practical application.
文摘Via database technology, a perfect lightning protection integrated service work platform is established, thereby realizing paperless data management of routine business.
基金Supported by Science Research Item of Changzhou Meteorological Bureau,China(1305)
文摘Due to its large and metallic structure, large recreation facility is easy to be struck by lightning. Meanwhile, the lightning strike conse- quences are serious, including threat to the life and property safety of tourists, great impact on society and bad effect on the development of tourism. As a result, lightning protection of recreation facility is particularly important. Taking the Ferris wheel of Zijin Park as an example, its light- ning risk and structural characteristics were analyzed to make reasonable solving scheme. Through the study about lightning risks of recreational fa- cilities with different structures and geographical positions, the lightning protection differences between recreational facilities and the general lightning protection scheme were summarized.
文摘This paper is devoted to the study of the most suitable protocols needed to verify the lightning protection and ground resistance quality in a large-scale scientific facility located on a site with high risk of lightning strikes. We illustrate this work by reviewing a case study: the largest telescopes of the Northern Hemisphere Cherenkov Telescope Array, CTA-N. This array hosts sensitive and high-speed optoelectronics instrumentation and sits on a clear, free from obstacle terrain at around 2400 m above sea level. The site offers a top-quality sky but also features challenging conditions for a lightning protection system: the terrain is volcanic and has electrical resistivities well above 1 kOhm·m. In addition, the environment often exhibits humidities well below 5%, and strong winds pose challenging conditions. On the other hand, the </span><span style="font-family:Verdana;">high complexity of a Cherenkov telescope structure does not allow a straightforward</span><span style="font-family:Verdana;"> application of lightning protection standards. We describe here how the risk assessment of direct strike impacts was made and how contact voltages and ground system were both tested. Finite Element Simulation (COMSOL Multiphysics) has been used to estimate the current flowing through the parts of the earthing system designed for the telescopes in the case of a direct strike impact. This work is intended to provide assistance to scientists and managers involved in the construction of scientific installations, particularly those in charge of defining verifiable reliability and safety requirements for lightning protection.
文摘An electronic information system is composed of multiple groups of components. With the improvement of technology, its accuracy is getting higher and higher. The voltage during normal operation is only a few volts, and the information current is only microamp, so the withstand voltage to lightning electromagnetic pulse is extremely low. In this paper, the negative impact of lightning and static electricity on the computer room of an electronic information system was analyzed firstly, and then the design for the lightning protection of the computer room was discussed.
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Based on Internet technology,modern wireless communication technology and new sensor technology,an intelligent protection and monitoring system of lightning disaster was established to collect lightning current(lightning intensity,frequency and time),induced lightning current and leakage current of surge protector(SPD),earthing resistance,working voltage,temperature and humidity in the lightning environment and other data in real time.Through the online analysis of visual data and automatic alarm beyond the preset value of cloud platform,it can realize the intelligent online monitoring and management of lightning protection devices,providing scientific and reliable lightning protection technical support for lightning protection and disaster reduction,and ensuring the smooth development and efficient management of lightning protection safety work.
文摘Under the influence of special terrain and climatic conditions,lightning weather in Ulanqab City is more frequent from June to August,and lightning disaster has become one of the important tasks of disaster prevention and mitigation.In this paper,based on the characteristics of lightning weather in Ulanqab City,the impact of lightning disaster on the city was analyzed,and lightning protection measures,such as strengthening supervision of lightning protection safety,establishing a long-term lightning protection mechanism,doing a good job in lightning protection construction and detection in key places,and further improving public awareness of lightning protection,were put forward to reduce and avoid urban lightning disasters as much as possible and ensure urban safety.
文摘The rail weighbridge system of a railway freight station is introduced firstly, and then the earthing method for protection of the rail weighbridge system against lightning based on YLG-60 equipotential bonding surge protection device is shown.
基金supported by the National Key Research and Development Program of China(No.2017YFC0703007)the Chinese MIIT Special Research Plan on Civil Aircraft(No.MJ-2015-H-G-103)+1 种基金the National Natural Science Foundation of China(No.52008137)the China Postdoctoral Science Foundation(Nos.2019TQ0079 and 2019M661288)。
文摘The non-metallic lightning strike protection film covering carbon fiber reinforced polymers(NM-LSP covering CFRP)can reduce the weight and thus the fuel consumption of aircraft by replacing the traditional lightning strike protection(LSP)materials.In the present study,in order to study the environmental influence of utilizing NM-LSP covering CFRP in an aircraft elevator,a new elevator was designed and manufactured,replacing the aluminium net and glass fiber reinforced polymers(GFRP)with NM-LSP covering CFRP,with the same mechanical and LSP abilities.A comparative life cycle assessment was conducted between the two kinds of aircraft elevators,including material extraction,transportation,elevator manufacturing phase,service phase,and end-of-life procedures.Additionally,the environmental impacts of producing two LSP materials were compared by considering the environmental effects of different buy-to-fly ratios and recycling strategies on the production of aluminium net.The analysis indicates that the new elevator achieved reduction for all the environmental impact categories used,such as human toxicity potential and marine aquatic ecotoxicity potential(3.83%and 3.20%reduction).Furthermore,it is found that the service phase makes the greatest contribution to the environmental impact of the elevators under investigation.When recycling is excluded,NM-LSP covering CFRP is more environmentally friendly than the traditional material.At the same time,CFRP prepreg and electricity from the production of NM-LSP covering CFRP contribute to a higher environmental impact compared to the NM-LSP film.From the sensitivity analysis,it is believed that NM-LSP covering CFRP can reduce environmental impact compared with traditional LSP materials.
基金Project supported by China Postdoctoral Science Foundation （ 10000072311030 ）, Scienee technology Research Foundation of Shandong University of China {10000080398125）.
基金partly supported by National Natural Science Foundation of China(No.51577098)the State Grid Corporation of China,and China Southern Power Grid
文摘Different types of lightning air terminals have been designed over the years.Concern regarding the effect of different types of air terminals,especially the early streamer emission(ESE)-type,remains controversial.This paper describes the discharge characteristics of different types of air terminals,two of which are quite similar to the ESE-type dynasphere,and concludes that the tested non-standard air terminals have discharge characteristics similar to those of Franklin rods and that their lightning protection performance should be similar.
文摘In recent years,several failures of double circuit transmission line on the same tower due to lightning were happened in Beijing power grid.Although it can be reclosed successful,the lightning strike caused a grave threat to the power grid security.The cause of the accident and the accident process were studied for the sake of further understanding of the impact of lightning on power grid.As an example,110 kV double circuit transmission line(Xilong-line) was analyzed.At first,the system topology was given.Through the analysis on relay protection actions and the fault recorder data,over voltage on the insulator strings was calculated.Based on the analysis and the calculation,accident cause and the process were presented respectively.Secondly,it comes to the conclusion that the lightning failure was caused by counterattack.The wave of the lightning over voltage would spread to the not grounded neutral point of the transformers,and make the neutral protective gap breakdown,then cause freewheeling with the frequency of 50 Hz.As results of the relay protection,the double circuit transmission line all tripped out.Finally,the causes of the accident were proposed that included terrain features,large corner towers,strong thunderstorm weather and poor grounded contact of the tower.
文摘Taking a lightning accident of one unit as clue,weather characteristics and radar echo of lightning disaster occurrence were firstly checked, cause of lightning strike was analyzed,and focus and method of lightning protection in the units were summarized,which was beneficial to reducing loss and risk caused by lightning.
基金Supported by Technology Research and Development Project of Strong Electromagnetic Pulse Protection (Lightning) of Sea Wind Field in Guangdong Yuedian Zhuhai Biqing Bay (YJW-PK23010)。
文摘The latest research shows that the ions generated by the corona discharge of lightning rod have dual functions of attracting and shielding lightning discharge. After the lightning rod is installed at a certain height on the ground,the lightning rod tip reaches the corona threshold to ionize the surrounding air and generate positive and negative ions under the action of the electric field at the end of the lightning downward leader. Constrained by Coulomb’s Law,its positive ions( opposite charges attract each other) form an upward leader( streamer),which moves towards the end of the lightning downward leader and is connected to the downward leader,establishing a discharge channel to attract lightning to the needle tip and discharge the current to the ground,and playing a role in attracting lightning. Its negative ions are repelled by the electric field at the end of the lightning downward leader( repelled by isotropic charges) and influenced by the wind,and diffuse in the downwind area to form an ion cloud,inhibiting the growth of corona at the tip of ground objects,and playing a role in shielding lightning. In this paper,Franklin’s understanding of the role of lightning rod and Yang Shaojie’s new definition of the working principle of lightning rod are briefly introduced. The formation mechanism,distribution characteristics,shielding effect,and impact on lightning strike point distribution of ion clouds are analyzed. Additionally,the important role of shielding effects of ion clouds in regional lightning protection is introduced,which provides a theoretical basis for the correct understanding and use of lightning rod.
