Pub Date : 2023-06-12DOI: 10.1109/APL57308.2023.10182034
S. Gu, Fengquan Li, Pei Wang, Jian Li, Zhe Li, Hantao Tao
Lightning strikes are the primary cause of transmission network failures. Strengthening the monitoring and research of lightning activities contributes to the scientific protection against lightning strikes in power grids. Therefore, based on the lightning detection results of the State Grid of China from 2012 to 2021, this article analyzes the spatiotemporal distribution characteristics of lightning at different scales, and proposes a thunderstorm intensity parameter to measure the intensity of lightning activity. The results indicate that the number of total return stroke in the State Grid region from 2012 to 2021 was approximately 166 million, 2.1 times the number of first return stroke. The monthly variation showed a unimodal distribution, with June to August being the peak period of lightning activity. The spatial distribution of lightning activities was uneven, showing a distribution trend of more in east, central, and north China, while less in northwest and northeast China. The positive-polarity ratio of the first return stroke in various regions was greater than that of total return stroke, with east and central China being the most obvious. The median current in north China and east China was relatively small, and the median current of the first and all return stroke was comparable. The median current in central China, northeast China, and northwest China was relatively large, and the median current of the first return stroke was slightly greater than the median current of all return strokes. The results show that 30 min and $0.3^{circ}times 0.3^{circ}$ can be initially selected as the statistical time $Delta {mathrm{t}}$ and grid area for dense thunderstorms to measure the time intensity of lightning activity. The trend of changes in the number of lightning strikes was basically consistent with the number of dense thunderstorms.
{"title":"Analysis of Distribution Characteristics of Cloud-to-ground Lightning at Different Spatiotemporal Scales","authors":"S. Gu, Fengquan Li, Pei Wang, Jian Li, Zhe Li, Hantao Tao","doi":"10.1109/APL57308.2023.10182034","DOIUrl":"https://doi.org/10.1109/APL57308.2023.10182034","url":null,"abstract":"Lightning strikes are the primary cause of transmission network failures. Strengthening the monitoring and research of lightning activities contributes to the scientific protection against lightning strikes in power grids. Therefore, based on the lightning detection results of the State Grid of China from 2012 to 2021, this article analyzes the spatiotemporal distribution characteristics of lightning at different scales, and proposes a thunderstorm intensity parameter to measure the intensity of lightning activity. The results indicate that the number of total return stroke in the State Grid region from 2012 to 2021 was approximately 166 million, 2.1 times the number of first return stroke. The monthly variation showed a unimodal distribution, with June to August being the peak period of lightning activity. The spatial distribution of lightning activities was uneven, showing a distribution trend of more in east, central, and north China, while less in northwest and northeast China. The positive-polarity ratio of the first return stroke in various regions was greater than that of total return stroke, with east and central China being the most obvious. The median current in north China and east China was relatively small, and the median current of the first and all return stroke was comparable. The median current in central China, northeast China, and northwest China was relatively large, and the median current of the first return stroke was slightly greater than the median current of all return strokes. The results show that 30 min and $0.3^{circ}times 0.3^{circ}$ can be initially selected as the statistical time $Delta {mathrm{t}}$ and grid area for dense thunderstorms to measure the time intensity of lightning activity. The trend of changes in the number of lightning strikes was basically consistent with the number of dense thunderstorms.","PeriodicalId":371726,"journal":{"name":"2023 12th Asia-Pacific International Conference on Lightning (APL)","volume":"15 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":"133877186","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/APL57308.2023.10181833
Pocholo Miguel A. De Lara, Jerico Orejudos, Jeffery A. Aborot, G. V. Lopez
An existing methodology for locating lightning events involves measuring the differences between the times when the signals reach the remote receivers located in different locations. This method is commonly known as the time-of-arrival (ToA) method. However, such approach commonly requires the entire signal source to be present and requires a lot of data and consumes processing power. To address this, the lightning geolocation algorithm used under the Understanding Lightning and Thunderstorm Project (ULAT) only uses specific lightning signatures to determine the location of cloud-to-ground (CG) lightning events. One challenge with this approach, however, is that it reduces the precision of the localization algorithm being used. This is also prone to the false selection of lightning events.In this paper, we investigate the performance of the existing implementation of the ULAT lightning geolocation algorithm and introduce improvements to the algorithm by (1) experimenting with different time-of-arrival algorithms using the same datasets, (2) adding a refining step using L-BFGS-B minimization, (3) using the sferic signal start time from the lightning data for sferic matching, (4) estimating location errors using Monte Carlo simulations. The geolocation results are then overlaid with the HIMAWARI satellite images to evaluate its relative performance in tracking the typhoon Noru (Karding) last September 25, 2022, and on a PAGASA thunderstorm advisory last November 15, 2022.
{"title":"Development and Initial Performance Assessment of The ULAT VLF Lightning Detection System in The Philippines","authors":"Pocholo Miguel A. De Lara, Jerico Orejudos, Jeffery A. Aborot, G. V. Lopez","doi":"10.1109/APL57308.2023.10181833","DOIUrl":"https://doi.org/10.1109/APL57308.2023.10181833","url":null,"abstract":"An existing methodology for locating lightning events involves measuring the differences between the times when the signals reach the remote receivers located in different locations. This method is commonly known as the time-of-arrival (ToA) method. However, such approach commonly requires the entire signal source to be present and requires a lot of data and consumes processing power. To address this, the lightning geolocation algorithm used under the Understanding Lightning and Thunderstorm Project (ULAT) only uses specific lightning signatures to determine the location of cloud-to-ground (CG) lightning events. One challenge with this approach, however, is that it reduces the precision of the localization algorithm being used. This is also prone to the false selection of lightning events.In this paper, we investigate the performance of the existing implementation of the ULAT lightning geolocation algorithm and introduce improvements to the algorithm by (1) experimenting with different time-of-arrival algorithms using the same datasets, (2) adding a refining step using L-BFGS-B minimization, (3) using the sferic signal start time from the lightning data for sferic matching, (4) estimating location errors using Monte Carlo simulations. The geolocation results are then overlaid with the HIMAWARI satellite images to evaluate its relative performance in tracking the typhoon Noru (Karding) last September 25, 2022, and on a PAGASA thunderstorm advisory last November 15, 2022.","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":"132758870","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/APL57308.2023.10181434
S. Pedeboy
The evolution of the local lightning density observed before and after the construction of a group of wind farms installed in a mountainous region of France is analyzed using an 18-year period lightning data. Considering the effect of the limited upward lightning detection efficiency of the lightning locating system on the data, the enhancement factor is estimated to be 3.9 times the natural lightning density before the construction. This result is half the correction factor suggested by the IEC61400-24:2019 methodology, but because it is based on conservative assumptions and high-resolution lightning observations it is considered realistic. Finally, this study also brought some materials and comments on the methodology proposed in the standard guidelines.
{"title":"Estimation of the average annual number of lightning flashes to a group of wind turbines in France","authors":"S. Pedeboy","doi":"10.1109/APL57308.2023.10181434","DOIUrl":"https://doi.org/10.1109/APL57308.2023.10181434","url":null,"abstract":"The evolution of the local lightning density observed before and after the construction of a group of wind farms installed in a mountainous region of France is analyzed using an 18-year period lightning data. Considering the effect of the limited upward lightning detection efficiency of the lightning locating system on the data, the enhancement factor is estimated to be 3.9 times the natural lightning density before the construction. This result is half the correction factor suggested by the IEC61400-24:2019 methodology, but because it is based on conservative assumptions and high-resolution lightning observations it is considered realistic. Finally, this study also brought some materials and comments on the methodology proposed in the standard guidelines.","PeriodicalId":371726,"journal":{"name":"2023 12th Asia-Pacific International Conference on Lightning (APL)","volume":"350 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":"115503956","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/APL57308.2023.10181585
Zherui Cui, Yao Yao, Zijian Li, W. Shen, Bo Zhang, Jinliang He
Harvesting power from ground wires is an emergent method to solve the power supply issues of online monitoring units in the overhead transmission lines. However, the power harvesting device based on ground wire has a much higher probability to be exposed to lightning overvoltage or overcurrent. Therefore, this paper studies ground wire impulse current characteristics under various lightning strike situations to guide the design of protection module in the power harvesting device based on ground wire. Furthermore, a spectrum analysis is also conducted to study the refraction and reflection in the ground wire. Meanwhile, this paper discusses the influence of lightning impulse current waveform, span and impulse resistance of tower grounding device in the ground wire current.
{"title":"Characteristics of Ground Wire Currents along Transmission Line under Lightning Strikes","authors":"Zherui Cui, Yao Yao, Zijian Li, W. Shen, Bo Zhang, Jinliang He","doi":"10.1109/APL57308.2023.10181585","DOIUrl":"https://doi.org/10.1109/APL57308.2023.10181585","url":null,"abstract":"Harvesting power from ground wires is an emergent method to solve the power supply issues of online monitoring units in the overhead transmission lines. However, the power harvesting device based on ground wire has a much higher probability to be exposed to lightning overvoltage or overcurrent. Therefore, this paper studies ground wire impulse current characteristics under various lightning strike situations to guide the design of protection module in the power harvesting device based on ground wire. Furthermore, a spectrum analysis is also conducted to study the refraction and reflection in the ground wire. Meanwhile, this paper discusses the influence of lightning impulse current waveform, span and impulse resistance of tower grounding device in the ground wire current.","PeriodicalId":371726,"journal":{"name":"2023 12th Asia-Pacific International Conference on Lightning (APL)","volume":"3 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":"121162850","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/APL57308.2023.10181500
W. F. Wan Ahmad, M. H. Mohamad Roslan, J. Jasni, M. Ab-Kadir
The vital reason of having a grounding system in any power system installation is safety. There is a need to ensure that any fault current could be dispersed into soil at the shortest time possible during both normal and fault circumstances. There are many ways to be done in order to obtain the best grounding system with low earth resistance values. In one of the way is by adding NEM to the soil in the vicinity of a vertical ground conductor. This study employed four vertical ground conductors that were installed with NEM to investigate their performances, environmental and economic effects, and compared to a Reference grounding system with no NEM added in the vicinity of the ground conductor. The chosen NEM were Bentonite and Kenaf, as both materials are able to absorb and retain moisture in the surrounding soil. Four different mixtures of such NEMs were employed, i.e., 100% Bentonite, 100% Kenaf, Bentonite and Kenaf Mix A, and Bentonite and Kenaf Mix B. Note that these grounding systems were installed at a spacious site near to SGS, UPM where earth resistance of each grounding system was measured daily for 5 months, starting from 19$^{mathrm{th}}$ December 2016 until 18th May 2017. It is found that after 150 days, the performance of the grounding systems in descending order were 100% Bentonite, Bentonite and Kenaf Mix A, and Bentonite and Kenaf Mix B, Reference, and 100% Kenaf grounding systems, with 20.74%, 41.66%, 43.59%, 93.27% and 103.50% measured earth resistance value compared to the day-0 earth resistance value of the Reference grounding system, respectively. This clearly demonstrated that 100% Bentonite is much better NEM to be used in grounding system installations compared to 100% Kenaf. However, Mix A grounding system also showed a promising performance once in a while, while Mix B did not. Therefore, it could be compelling to further explore the behaviour of mixing Bentonite and Kenaf as grounding enhancement materials with other various ratios for future works. Note that Bentonite ratio was more in Mix A compared to Mix B.
{"title":"Performance of Bentonite and Kenaf Mixtures as Grounding Enhancement Materials","authors":"W. F. Wan Ahmad, M. H. Mohamad Roslan, J. Jasni, M. Ab-Kadir","doi":"10.1109/APL57308.2023.10181500","DOIUrl":"https://doi.org/10.1109/APL57308.2023.10181500","url":null,"abstract":"The vital reason of having a grounding system in any power system installation is safety. There is a need to ensure that any fault current could be dispersed into soil at the shortest time possible during both normal and fault circumstances. There are many ways to be done in order to obtain the best grounding system with low earth resistance values. In one of the way is by adding NEM to the soil in the vicinity of a vertical ground conductor. This study employed four vertical ground conductors that were installed with NEM to investigate their performances, environmental and economic effects, and compared to a Reference grounding system with no NEM added in the vicinity of the ground conductor. The chosen NEM were Bentonite and Kenaf, as both materials are able to absorb and retain moisture in the surrounding soil. Four different mixtures of such NEMs were employed, i.e., 100% Bentonite, 100% Kenaf, Bentonite and Kenaf Mix A, and Bentonite and Kenaf Mix B. Note that these grounding systems were installed at a spacious site near to SGS, UPM where earth resistance of each grounding system was measured daily for 5 months, starting from 19$^{mathrm{th}}$ December 2016 until 18th May 2017. It is found that after 150 days, the performance of the grounding systems in descending order were 100% Bentonite, Bentonite and Kenaf Mix A, and Bentonite and Kenaf Mix B, Reference, and 100% Kenaf grounding systems, with 20.74%, 41.66%, 43.59%, 93.27% and 103.50% measured earth resistance value compared to the day-0 earth resistance value of the Reference grounding system, respectively. This clearly demonstrated that 100% Bentonite is much better NEM to be used in grounding system installations compared to 100% Kenaf. However, Mix A grounding system also showed a promising performance once in a while, while Mix B did not. Therefore, it could be compelling to further explore the behaviour of mixing Bentonite and Kenaf as grounding enhancement materials with other various ratios 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":"22 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":"129355614","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/APL57308.2023.10182077
Ahmad Hafiz Mohd Hashim, N. D. Ahmad, N. Azis, J. Jasni, M. Radzi, M. Kozako, M. Jamil
This paper presents an examination on acoustic emission (AE) partial discharge (PD) signal characteristic in oil in the presence of pressboard. First, a test tank was fabricated whereby the PD was generated through needle-plane electrode configuration. Next, the pressboard was placed at the PD source. The electrical PD was measured through Impedance Matching Circuit (IMC) whereby the AE PD signal was measured using AE sensor. Based on the measured AE PD signal, the time of arrival (TOA), amplitude, duration, and distance between PD location and AE sensor was examined. Location error and root mean square error (RMSE) was used to evaluate the PD localization error rate. It is found that the presence of pressboard has an impact on PD localization location error rate and RMSE.
{"title":"Examination on Acoustic Emission Partial Discharge Localization Error Rate in Oil in the Presence of Pressboard","authors":"Ahmad Hafiz Mohd Hashim, N. D. Ahmad, N. Azis, J. Jasni, M. Radzi, M. Kozako, M. Jamil","doi":"10.1109/APL57308.2023.10182077","DOIUrl":"https://doi.org/10.1109/APL57308.2023.10182077","url":null,"abstract":"This paper presents an examination on acoustic emission (AE) partial discharge (PD) signal characteristic in oil in the presence of pressboard. First, a test tank was fabricated whereby the PD was generated through needle-plane electrode configuration. Next, the pressboard was placed at the PD source. The electrical PD was measured through Impedance Matching Circuit (IMC) whereby the AE PD signal was measured using AE sensor. Based on the measured AE PD signal, the time of arrival (TOA), amplitude, duration, and distance between PD location and AE sensor was examined. Location error and root mean square error (RMSE) was used to evaluate the PD localization error rate. It is found that the presence of pressboard has an impact on PD localization location error rate and RMSE.","PeriodicalId":371726,"journal":{"name":"2023 12th Asia-Pacific International Conference on Lightning (APL)","volume":"18 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":"128735187","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/APL57308.2023.10181718
S. Chowdhury, A. Sukesh, U. Kumar
Long upward connecting leaders are seen from tall objects on ground. The bridging between the downward and upward leaders through their streamer zones, initiates the return stroke. Two current waves, one heading towards the ground and the other moving upward are initiated. The downward moving wave reaches ground through the object and then gets reflected (back removed). The velocity of propagation of the downward wave is expected to be different in the channel and the tall object (or down conductor). The upward wave then catches up with the wavefront and the literature is divided on its fate. In any case, the spatio-temporal distribution of the current, at least below the bridging zone, can be expected to be different from that with strike to ground. This finds interest not only from the phenomena perspective, but also from the protectional aspects. In this preliminary work, an investigation on the spatio-temporal current evolution is carried out for strokes with significant upward leaders arising from a 100 m tall slender tower (down conductor). It will be compared with the strike to ground case for the same leader configuration.
{"title":"Preliminary Study on Spatio-Temporal Currents in the Strokes with Long Upward Leaders","authors":"S. Chowdhury, A. Sukesh, U. Kumar","doi":"10.1109/APL57308.2023.10181718","DOIUrl":"https://doi.org/10.1109/APL57308.2023.10181718","url":null,"abstract":"Long upward connecting leaders are seen from tall objects on ground. The bridging between the downward and upward leaders through their streamer zones, initiates the return stroke. Two current waves, one heading towards the ground and the other moving upward are initiated. The downward moving wave reaches ground through the object and then gets reflected (back removed). The velocity of propagation of the downward wave is expected to be different in the channel and the tall object (or down conductor). The upward wave then catches up with the wavefront and the literature is divided on its fate. In any case, the spatio-temporal distribution of the current, at least below the bridging zone, can be expected to be different from that with strike to ground. This finds interest not only from the phenomena perspective, but also from the protectional aspects. In this preliminary work, an investigation on the spatio-temporal current evolution is carried out for strokes with significant upward leaders arising from a 100 m tall slender tower (down conductor). It will be compared with the strike to ground case for the same leader configuration.","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":"117009746","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/APL57308.2023.10182214
Yun Pan, D. Zheng, Yijun Zhang
A dataset consisting of 2331 negative cloud-to-ground (NCG) lighting flashes derived from the Oklahoma Lightning Mapping Array (OK-LMA) and the National Lightning Detection Network (NLDN) during 2010–2012 was used to analyze the multiplicity characteristic. The mean multiplicity of the NCG lightning was 2.40. The relationship between multiplicity and lightning initiation height showed that the NCG lightning with multiple return strokes (MRSs) preferred to be initiated below 6km, while the proportion of single return strokes (SRS) lightning was greater for those initiation heights above 6km. The spatiotemporal scales, the peak current of the first RS, and the maximum peak current all increased with increasing multiplicity.
{"title":"The characteristic of negative cloud-to-ground lightning with multiple return strokes","authors":"Yun Pan, D. Zheng, Yijun Zhang","doi":"10.1109/APL57308.2023.10182214","DOIUrl":"https://doi.org/10.1109/APL57308.2023.10182214","url":null,"abstract":"A dataset consisting of 2331 negative cloud-to-ground (NCG) lighting flashes derived from the Oklahoma Lightning Mapping Array (OK-LMA) and the National Lightning Detection Network (NLDN) during 2010–2012 was used to analyze the multiplicity characteristic. The mean multiplicity of the NCG lightning was 2.40. The relationship between multiplicity and lightning initiation height showed that the NCG lightning with multiple return strokes (MRSs) preferred to be initiated below 6km, while the proportion of single return strokes (SRS) lightning was greater for those initiation heights above 6km. The spatiotemporal scales, the peak current of the first RS, and the maximum peak current all increased with increasing multiplicity.","PeriodicalId":371726,"journal":{"name":"2023 12th Asia-Pacific International Conference on Lightning (APL)","volume":"115 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":"126778420","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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