Pub Date : 2023-06-12DOI: 10.1109/APL57308.2023.10181896
Chandima Gomes, M. Guthrie
Personal and group lightning safety modules for outdoor applications are designed and analyzed by simulation. The international standards on lightning protection (IEC 62305) comprehensively detail the design and construction of protection for modern construction. However, the applicability of such standard practices in safeguarding human beings in underprivileged communities from the five basic lightning injury mechanisms (cost factors, complications in implementation, strategic issues such as weight, stability, theft, etc.) is a long-standing question. In this study, we construct lightning protection schemes for individual and group applications, on both land and water, which will lead to the safeguarding of human lives of both underprivileged communities and amusement/leisure seekers. Simulations are done with PSCAD and COMSOL software to find the current and potential distribution in pre-determined metallic structures to compute the optimum dimensions, best-suited materials, and insulation requirements to minimize direct strike, side flash, touch potential, step potential and upward streamer hazards as well as to ensure mechanical and thermal stability. The best-performing designs are proposed to be constructed and tested by applying high voltage and current impulses under laboratory conditions to justify the suitability of the schemes as lightning safety measures for the general public. The proven structures could then be patented and commercialized for public applications.
{"title":"Development of cost-effective lightning protection measures for underprivileged communities","authors":"Chandima Gomes, M. Guthrie","doi":"10.1109/APL57308.2023.10181896","DOIUrl":"https://doi.org/10.1109/APL57308.2023.10181896","url":null,"abstract":"Personal and group lightning safety modules for outdoor applications are designed and analyzed by simulation. The international standards on lightning protection (IEC 62305) comprehensively detail the design and construction of protection for modern construction. However, the applicability of such standard practices in safeguarding human beings in underprivileged communities from the five basic lightning injury mechanisms (cost factors, complications in implementation, strategic issues such as weight, stability, theft, etc.) is a long-standing question. In this study, we construct lightning protection schemes for individual and group applications, on both land and water, which will lead to the safeguarding of human lives of both underprivileged communities and amusement/leisure seekers. Simulations are done with PSCAD and COMSOL software to find the current and potential distribution in pre-determined metallic structures to compute the optimum dimensions, best-suited materials, and insulation requirements to minimize direct strike, side flash, touch potential, step potential and upward streamer hazards as well as to ensure mechanical and thermal stability. The best-performing designs are proposed to be constructed and tested by applying high voltage and current impulses under laboratory conditions to justify the suitability of the schemes as lightning safety measures for the general public. The proven structures could then be patented and commercialized for public applications.","PeriodicalId":371726,"journal":{"name":"2023 12th Asia-Pacific International Conference on Lightning (APL)","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114675791","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 : 2023-06-12DOI: 10.1109/APL57308.2023.10181338
S. Sekioka
A grounding conductor (GC) is represented by a distributed-parameter line. Therefore, the voltage and current propagating on the GC should be treated as surge phenomena. On the other hand, grounding resistances are noted by constant matrix without propagation time between grounding electrodes (GEs). A GC is often used to connect GEs. Induced voltages are raised on the GEs before the voltage propagating along the GC reaches if the propagation time of mutual grounding resistance is ignored. Thus, accurate surge analysis for large grounding system should consider the propagation time between GEs. The author has proposed a simulation model of mutual grounding resistance considering the propagation time. This paper describes the proposed model to be used in the EMTP.
{"title":"EMTP Simulation Model for Mutual Grounding Resistance considering Propagation Time","authors":"S. Sekioka","doi":"10.1109/APL57308.2023.10181338","DOIUrl":"https://doi.org/10.1109/APL57308.2023.10181338","url":null,"abstract":"A grounding conductor (GC) is represented by a distributed-parameter line. Therefore, the voltage and current propagating on the GC should be treated as surge phenomena. On the other hand, grounding resistances are noted by constant matrix without propagation time between grounding electrodes (GEs). A GC is often used to connect GEs. Induced voltages are raised on the GEs before the voltage propagating along the GC reaches if the propagation time of mutual grounding resistance is ignored. Thus, accurate surge analysis for large grounding system should consider the propagation time between GEs. The author has proposed a simulation model of mutual grounding resistance considering the propagation time. This paper describes the proposed model to be used in the EMTP.","PeriodicalId":371726,"journal":{"name":"2023 12th Asia-Pacific International Conference on Lightning (APL)","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121962919","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 : 2023-06-12DOI: 10.1109/APL57308.2023.10181858
Xiangen Zhao, Yaping Du, Lili Guo, Yang Liu, Junjia He
It is well known that the negative leader in the air develops in a stepwise manner, with each step originating from a space stem. However, the formation mechanism of a space stem remains unknown, leading to a blockage in the study on negative leader discharge. One of the main reasons is the lack of observations of space stems. For this reason, and as a continuation of our work, this paper focuses on the initiation location of the space stems. We have designed experimental conditions to enable space stem observation using a high-speed camera. Through processing the experimental images, it is found that the location where the space stems start to be formed may be located at the boundary of the previous corona streamer discharge, or inside the pre-corona streamer region, but at the edge of the intense discharge area. These findings may help to further Figure out the formation mechanism of a space stem in long negative sparks in the air.
{"title":"Location of the space stem in long negative laboratory sparks","authors":"Xiangen Zhao, Yaping Du, Lili Guo, Yang Liu, Junjia He","doi":"10.1109/APL57308.2023.10181858","DOIUrl":"https://doi.org/10.1109/APL57308.2023.10181858","url":null,"abstract":"It is well known that the negative leader in the air develops in a stepwise manner, with each step originating from a space stem. However, the formation mechanism of a space stem remains unknown, leading to a blockage in the study on negative leader discharge. One of the main reasons is the lack of observations of space stems. For this reason, and as a continuation of our work, this paper focuses on the initiation location of the space stems. We have designed experimental conditions to enable space stem observation using a high-speed camera. Through processing the experimental images, it is found that the location where the space stems start to be formed may be located at the boundary of the previous corona streamer discharge, or inside the pre-corona streamer region, but at the edge of the intense discharge area. These findings may help to further Figure out the formation mechanism of a space stem in long negative sparks in the air.","PeriodicalId":371726,"journal":{"name":"2023 12th Asia-Pacific International Conference on Lightning (APL)","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122028653","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 : 2023-06-12DOI: 10.1109/APL57308.2023.10181684
S. C. Lim, Md Mahmudul Hasan, Ong Chang Shen
Since the dawn of civilization, humans have been fascinated by one of the most common natural occurrences called lightning. It’s not just a fascinating but also dangerous occurrence for electrical equipment. Substation, which is one of the most important parts of power transmission and distribution, is susceptible to lightning strikes. If lightning directly strikes a substation, it may cause huge damage to the equipment of the substation. Thus, a proper lightning protection system is required in order to protect the substation. Striking distance is one of the most important aspects of a substation’s lightning protection design. This study aims to analyze the striking distance range for Japan, Austria, Brazil, Sweden and the USA based on methodologies and recorded lightning current found in the literature. The values of lightning peak current and types of lightning protection systems (mast/wire) are considered in the calculation of striking distance for the selected countries. Among the countries studied, the USA has the greatest striking distance range, while Sweden has the smallest. It is also observed that the striking distance range is significantly higher when the lightning mast is used instead of shield wire as lightning protection device. In addition, this paper presents a graphical representation of the recommended striking distance range for the selected countries which will help the designer to efficiently design the lightning protection system of substations for those selected countries.
{"title":"On the Striking Distance for the Design of Lightning Protection System for Substations in Selected Countries","authors":"S. C. Lim, Md Mahmudul Hasan, Ong Chang Shen","doi":"10.1109/APL57308.2023.10181684","DOIUrl":"https://doi.org/10.1109/APL57308.2023.10181684","url":null,"abstract":"Since the dawn of civilization, humans have been fascinated by one of the most common natural occurrences called lightning. It’s not just a fascinating but also dangerous occurrence for electrical equipment. Substation, which is one of the most important parts of power transmission and distribution, is susceptible to lightning strikes. If lightning directly strikes a substation, it may cause huge damage to the equipment of the substation. Thus, a proper lightning protection system is required in order to protect the substation. Striking distance is one of the most important aspects of a substation’s lightning protection design. This study aims to analyze the striking distance range for Japan, Austria, Brazil, Sweden and the USA based on methodologies and recorded lightning current found in the literature. The values of lightning peak current and types of lightning protection systems (mast/wire) are considered in the calculation of striking distance for the selected countries. Among the countries studied, the USA has the greatest striking distance range, while Sweden has the smallest. It is also observed that the striking distance range is significantly higher when the lightning mast is used instead of shield wire as lightning protection device. In addition, this paper presents a graphical representation of the recommended striking distance range for the selected countries which will help the designer to efficiently design the lightning protection system of substations for those selected countries.","PeriodicalId":371726,"journal":{"name":"2023 12th Asia-Pacific International Conference on Lightning (APL)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125724889","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 : 2023-06-12DOI: 10.1109/APL57308.2023.10181353
Masahiro Ueda, S. Yasui, Hidekazu Tanaka, Tomoaki Nonoyama, Y. Kunii
In the lightning protection design of medium-voltage distribution lines, the introduction of arcing horns with a zinc-oxide element to protect the insulated cables and insulators and primary cutout with a zinc-oxide element to protect transformers have reduced the damage by direct lightning strikes. However, the failure rate of lightning arrester elements used in these power distribution systems is increasing. In this study, we evaluated the failure risk of lightning arrester elements installed on utility poles based on the probability of lightning strikes exceeding the energy tolerance of each surge arrester element. As a result, when the insulators on a pole are unprotected, the elements of arresters installed on the poles adjacent to it on its either side and supporting the same phase line will have the highest failure risk.
{"title":"Risk Assessment of Surge Arresters for Efficient Maintenance of Medium-voltage Distribution Lines","authors":"Masahiro Ueda, S. Yasui, Hidekazu Tanaka, Tomoaki Nonoyama, Y. Kunii","doi":"10.1109/APL57308.2023.10181353","DOIUrl":"https://doi.org/10.1109/APL57308.2023.10181353","url":null,"abstract":"In the lightning protection design of medium-voltage distribution lines, the introduction of arcing horns with a zinc-oxide element to protect the insulated cables and insulators and primary cutout with a zinc-oxide element to protect transformers have reduced the damage by direct lightning strikes. However, the failure rate of lightning arrester elements used in these power distribution systems is increasing. In this study, we evaluated the failure risk of lightning arrester elements installed on utility poles based on the probability of lightning strikes exceeding the energy tolerance of each surge arrester element. As a result, when the insulators on a pole are unprotected, the elements of arresters installed on the poles adjacent to it on its either side and supporting the same phase line will have the highest failure risk.","PeriodicalId":371726,"journal":{"name":"2023 12th Asia-Pacific International Conference on Lightning (APL)","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128917639","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 : 2023-06-12DOI: 10.1109/APL57308.2023.10181750
N. Hatta, N. Abdullah, M. Osman, Azwadi Mohamad
This paper provides an overview of the cloud-to-ground lightning events recorded by a lightning detection system (LDS) network in Peninsular Malaysia between 2018 and 2022. The existing LDS comprises five sensors, a central processor, a database management system, and real-time terminals for displaying lightning activity. In 2017, after fourteen years of operation, the network underwent an upgrade to the most recent system offered by Vaisala Inc., USA. This upgrade introduced the latest sensor generation technology, LDSN enhancements, and improvements in network performance. Additionally, the paper will discuss the utilization of collected cloud-to-cloud lightning data to enhance the reliability of distribution overhead lines.
{"title":"Statistical Cloud-to-Ground Lightning Data and Its Implementation for 33kV Overhead Line in Peninsular Malaysia","authors":"N. Hatta, N. Abdullah, M. Osman, Azwadi Mohamad","doi":"10.1109/APL57308.2023.10181750","DOIUrl":"https://doi.org/10.1109/APL57308.2023.10181750","url":null,"abstract":"This paper provides an overview of the cloud-to-ground lightning events recorded by a lightning detection system (LDS) network in Peninsular Malaysia between 2018 and 2022. The existing LDS comprises five sensors, a central processor, a database management system, and real-time terminals for displaying lightning activity. In 2017, after fourteen years of operation, the network underwent an upgrade to the most recent system offered by Vaisala Inc., USA. This upgrade introduced the latest sensor generation technology, LDSN enhancements, and improvements in network performance. Additionally, the paper will discuss the utilization of collected cloud-to-cloud lightning data to enhance the reliability of distribution overhead lines.","PeriodicalId":371726,"journal":{"name":"2023 12th Asia-Pacific International Conference on Lightning (APL)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130962706","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 : 2023-06-12DOI: 10.1109/APL57308.2023.10182068
Yu Wang, Ze Liu, Fengquan Li, Zhe Li, Jian Li, S. Gu
Addressing the issue that the mutual shielding effect of several wind turbines is not fully considered in the current techniques of assessing the lightning risk of wind farms. This study suggests a Voronoi diagram-based method for analyzing lightning activity in wind farm with wind turbine clusters. The outcomes of lightning activity analysis using the conventional grid approach and the Voronoi diagram method suggested in this research are contrasted using a wind farm in Yunnan Province of China as an example. It demonstrates that the suggested approach is better suited for determining the lightning risk associated with a single wind turbine. It is capable of performing an analysis of the lightning parameters of a single wind turbine, including the cloud-ground lightning density, positive lightning ratio, median peak current, and average number of lightning return strokes, etc. Additionally, this approach may detect changes in pertinent lightning parameters both before and after the wind farm is set up. Therefore, it is more appropriate to offer technical assistance to wind farms, especially large wind farms, in order to develop specialized lightning protection strategies.
{"title":"Analysis of Lightning Activities in Wind Farm Based on Lightning Location data and Voronoi Diagram","authors":"Yu Wang, Ze Liu, Fengquan Li, Zhe Li, Jian Li, S. Gu","doi":"10.1109/APL57308.2023.10182068","DOIUrl":"https://doi.org/10.1109/APL57308.2023.10182068","url":null,"abstract":"Addressing the issue that the mutual shielding effect of several wind turbines is not fully considered in the current techniques of assessing the lightning risk of wind farms. This study suggests a Voronoi diagram-based method for analyzing lightning activity in wind farm with wind turbine clusters. The outcomes of lightning activity analysis using the conventional grid approach and the Voronoi diagram method suggested in this research are contrasted using a wind farm in Yunnan Province of China as an example. It demonstrates that the suggested approach is better suited for determining the lightning risk associated with a single wind turbine. It is capable of performing an analysis of the lightning parameters of a single wind turbine, including the cloud-ground lightning density, positive lightning ratio, median peak current, and average number of lightning return strokes, etc. Additionally, this approach may detect changes in pertinent lightning parameters both before and after the wind farm is set up. Therefore, it is more appropriate to offer technical assistance to wind farms, especially large wind farms, in order to develop specialized lightning protection strategies.","PeriodicalId":371726,"journal":{"name":"2023 12th Asia-Pacific International Conference on Lightning (APL)","volume":"114 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127966209","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 : 2023-06-12DOI: 10.1109/APL57308.2023.10181709
F. A. Rahman, U. Amirulddin, M. Kadir, M. Osman
This paper presents a study comparing the performance of a fourth rail direct current (DC) urban transit system when affected by an indirect lightning strike. Two different designs were used: one with a Cast Epoxy (CE) bracket equipped with a 3EB4-010 arrester, and the other with a Glass Reinforced Plastic (GRP) bracket equipped with a PDTA09 arrester. To replicate the indirect lightning strike, a lightning induced overvoltage was generated using the Rusck model. The model utilized the sum of two Heidler functions as the input for the lightning channel base current, assuming a perfectly conducting ground. The objective of this study is to determine whether an indirect lightning strike has any impact on the performance of the insulated rail bracket and station arrester of the LRT Kelana Jaya line, considering their different materials and residual voltage limits, respectively. Simulations were conducted using the Electromagnetic Transients Program - Restructured Version (EMTP-RV), and the performance of the two designs was compared when subjected to a 30 kA $(5/ 80 mu mathrm{s})$ induced current. The results showed that the GRP bracket, which has a higher permittivity, performed better when paired with the PDTA09 arrester, which has a lower residual voltage limit. This combination resulted in slightly lower induced overvoltage and significantly lower residual voltage being clamped by the station arrester.
本文介绍了一项比较四轨直流(DC)城市交通系统在受间接雷击影响时的性能的研究。使用了两种不同的设计:一种是带有3EB4-010避雷器的铸环氧树脂(CE)支架，另一种是带有PDTA09避雷器的玻璃钢(GRP)支架。为了复制间接雷击，使用Rusck模型产生了雷致过电压。该模型采用两个Heidler函数的和作为雷电通道基极电流的输入，假设有完美导电的地。本研究的目的是确定间接雷击是否会对轻型轻轨Kelana Jaya线的绝缘轨道支架和车站避雷器的性能产生影响，分别考虑它们的不同材料和残余电压限值。利用电磁瞬变程序重构版(EMTP-RV)进行了仿真，并比较了两种设计在30 kA $(5/ 80 mu mathm {s})$感应电流下的性能。结果表明，具有较高介电常数的GRP支架与具有较低残余电压极限的PDTA09避雷器配对时性能更好。这种组合导致了稍低的感应过电压和明显较低的剩余电压被车站避雷器箝制。
{"title":"Indirect Lightning Surge Analysis of Insulated Rail Bracket and Station Arrester in a Fourth Rail LRT System","authors":"F. A. Rahman, U. Amirulddin, M. Kadir, M. Osman","doi":"10.1109/APL57308.2023.10181709","DOIUrl":"https://doi.org/10.1109/APL57308.2023.10181709","url":null,"abstract":"This paper presents a study comparing the performance of a fourth rail direct current (DC) urban transit system when affected by an indirect lightning strike. Two different designs were used: one with a Cast Epoxy (CE) bracket equipped with a 3EB4-010 arrester, and the other with a Glass Reinforced Plastic (GRP) bracket equipped with a PDTA09 arrester. To replicate the indirect lightning strike, a lightning induced overvoltage was generated using the Rusck model. The model utilized the sum of two Heidler functions as the input for the lightning channel base current, assuming a perfectly conducting ground. The objective of this study is to determine whether an indirect lightning strike has any impact on the performance of the insulated rail bracket and station arrester of the LRT Kelana Jaya line, considering their different materials and residual voltage limits, respectively. Simulations were conducted using the Electromagnetic Transients Program - Restructured Version (EMTP-RV), and the performance of the two designs was compared when subjected to a 30 kA $(5/ 80 mu mathrm{s})$ induced current. The results showed that the GRP bracket, which has a higher permittivity, performed better when paired with the PDTA09 arrester, which has a lower residual voltage limit. This combination resulted in slightly lower induced overvoltage and significantly lower residual voltage being clamped by the station arrester.","PeriodicalId":371726,"journal":{"name":"2023 12th Asia-Pacific International Conference on Lightning (APL)","volume":"60 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127969771","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 : 2023-06-12DOI: 10.1109/APL57308.2023.10182199
Sayantan Das, U. Kumar
One of the major aspects of modern aircraft design is suitable protective measures against lightning which need a deeper understanding of the phenomena of a lightning strike to aircraft. Lightning attachment to aircraft can happen in two modes, aircraft-initiated and aircraft-intercepted. In the former, under the influence of thundercloud or lightning leader, the aircraft initiates stable bipolar leader discharges to complete the bridging. While in aircraft-intercepted mode, attachment takes place by direct streamer bridging between the lightning leader and aircraft. As different mechanisms are involved in the two modes of attachment, the corresponding probable initial attachment regions are also different. The mode of attachment is decided by the spatial field distribution, which mainly depends on the prospective stroke current and relative position of the descending leader. Different modes of attachment to aircraft are dominant at different stroke current ranges. The present work aims to identify the stroke-current ranges where aircraft-initiated and aircraft-intercepted modes are most probable. The investigation is carried out for small and medium-sized aircraft.
{"title":"Modes of lightning attachment to aircraft at different stroke currents and relative positions of descending lightning leader","authors":"Sayantan Das, U. Kumar","doi":"10.1109/APL57308.2023.10182199","DOIUrl":"https://doi.org/10.1109/APL57308.2023.10182199","url":null,"abstract":"One of the major aspects of modern aircraft design is suitable protective measures against lightning which need a deeper understanding of the phenomena of a lightning strike to aircraft. Lightning attachment to aircraft can happen in two modes, aircraft-initiated and aircraft-intercepted. In the former, under the influence of thundercloud or lightning leader, the aircraft initiates stable bipolar leader discharges to complete the bridging. While in aircraft-intercepted mode, attachment takes place by direct streamer bridging between the lightning leader and aircraft. As different mechanisms are involved in the two modes of attachment, the corresponding probable initial attachment regions are also different. The mode of attachment is decided by the spatial field distribution, which mainly depends on the prospective stroke current and relative position of the descending leader. Different modes of attachment to aircraft are dominant at different stroke current ranges. The present work aims to identify the stroke-current ranges where aircraft-initiated and aircraft-intercepted modes are most probable. The investigation is carried out for small and medium-sized aircraft.","PeriodicalId":371726,"journal":{"name":"2023 12th Asia-Pacific International Conference on Lightning (APL)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125296163","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 : 2023-06-12DOI: 10.1109/APL57308.2023.10182022
W. Ahmad, N. Marudin, J. Jasni, M. Ab-Kadir
Grounding system is essential in order to provide protection and to reduce the risk of severe electrical shock to the personnel as well as power system equipment during both normal and fault operation. A properly secured grounding system will enable the fault current to be dispersed to earth at the shortest time possible. Therefore, it is important to have a good grounding system in both normal and fault conditions, and one way to achieve that is by adding NEMs to treat its surrounding soil, where Bentonite and Zeolite were considered in this study. These two NEMs were mixed with water and their performances were compared to a Reference grounding system where there is no NEM installed in the vicinity of the ground conductor. The performance of such grounding systems were measured by the percentage reduction of their earth resistances, which were measured daily for 150 days, i.e. from 19th December 2016 till 18th May 2017 where Fall-of-Potential technique was employed. Note that in this work, it has found that the best grounding system in the descending order were Bentonite 100%, Bentonite and Zeolite Mix A, Bentonite and Zeolite Mix B, Zeolite 100% and References grounding systems. However, being Mix A was having a slightly better performance compared to its counterpart Mix B, it would be interesting to further engage with various mixtures of Bentonite and Zeolite as grounding enhancement materials for future works. Note that Bentonite ratio was more in Mix A compared to Mix B.
{"title":"Performance of Bentonite and Zeolite Mixtures as Grounding Enhancement Materials","authors":"W. Ahmad, N. Marudin, J. Jasni, M. Ab-Kadir","doi":"10.1109/APL57308.2023.10182022","DOIUrl":"https://doi.org/10.1109/APL57308.2023.10182022","url":null,"abstract":"Grounding system is essential in order to provide protection and to reduce the risk of severe electrical shock to the personnel as well as power system equipment during both normal and fault operation. A properly secured grounding system will enable the fault current to be dispersed to earth at the shortest time possible. Therefore, it is important to have a good grounding system in both normal and fault conditions, and one way to achieve that is by adding NEMs to treat its surrounding soil, where Bentonite and Zeolite were considered in this study. These two NEMs were mixed with water and their performances were compared to a Reference grounding system where there is no NEM installed in the vicinity of the ground conductor. The performance of such grounding systems were measured by the percentage reduction of their earth resistances, which were measured daily for 150 days, i.e. from 19th December 2016 till 18th May 2017 where Fall-of-Potential technique was employed. Note that in this work, it has found that the best grounding system in the descending order were Bentonite 100%, Bentonite and Zeolite Mix A, Bentonite and Zeolite Mix B, Zeolite 100% and References grounding systems. However, being Mix A was having a slightly better performance compared to its counterpart Mix B, it would be interesting to further engage with various mixtures of Bentonite and Zeolite as grounding enhancement materials for future works. Note that Bentonite ratio was more in Mix A compared to Mix B.","PeriodicalId":371726,"journal":{"name":"2023 12th Asia-Pacific International Conference on Lightning (APL)","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126719722","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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