Pub Date : 2016-09-01DOI: 10.1109/ICLP.2016.7791509
A. Chusov, G. Podporkin, M. Pinchuk, D. Ivanov, I. Murashov, V. Frolov
The multi-chamber systems (MCS) were recently proposed as a prospective lightning protection device. 2D-physical model of arc discharge in MCS discharge chamber was developed in order to perform tests of quenching efficiency for various chamber geometry. It was shown that in case of chamber configuration with hollow electrodes the backflow from electrodes appears at some time instance during the current pulse decay phase.
{"title":"Development of a physical 2-D model for arc quenching chamber of lightning protection multichamber systems","authors":"A. Chusov, G. Podporkin, M. Pinchuk, D. Ivanov, I. Murashov, V. Frolov","doi":"10.1109/ICLP.2016.7791509","DOIUrl":"https://doi.org/10.1109/ICLP.2016.7791509","url":null,"abstract":"The multi-chamber systems (MCS) were recently proposed as a prospective lightning protection device. 2D-physical model of arc discharge in MCS discharge chamber was developed in order to perform tests of quenching efficiency for various chamber geometry. It was shown that in case of chamber configuration with hollow electrodes the backflow from electrodes appears at some time instance during the current pulse decay phase.","PeriodicalId":373744,"journal":{"name":"2016 33rd International Conference on Lightning Protection (ICLP)","volume":"64 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133642558","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 : 2016-09-01DOI: 10.1109/ICLP.2016.7791366
Z. Kawasaki, M. Stock, M. Stanley, Ting Wu, T. Ushio, Y. Nakamura
The Lightning Interferometer via VHF Emission (LIVE) is the next iteration of broadband, interferometric lightning mapping systems. LIVE is a real-time capable instrument, producing images of lightning with a latency of about 5 seconds. Even under real-time operation conditions, LIVE will locate between 5000-50,000 sources in a single lightning flash, mapping out both the positive and negative breakdown portions of the flash.
{"title":"Lightning interferometer via VHF Emission (LIVE)","authors":"Z. Kawasaki, M. Stock, M. Stanley, Ting Wu, T. Ushio, Y. Nakamura","doi":"10.1109/ICLP.2016.7791366","DOIUrl":"https://doi.org/10.1109/ICLP.2016.7791366","url":null,"abstract":"The Lightning Interferometer via VHF Emission (LIVE) is the next iteration of broadband, interferometric lightning mapping systems. LIVE is a real-time capable instrument, producing images of lightning with a latency of about 5 seconds. Even under real-time operation conditions, LIVE will locate between 5000-50,000 sources in a single lightning flash, mapping out both the positive and negative breakdown portions of the flash.","PeriodicalId":373744,"journal":{"name":"2016 33rd International Conference on Lightning Protection (ICLP)","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114710657","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 : 2016-09-01DOI: 10.1109/ICLP.2016.7791367
E. Nicolopoulou, A. Alexandrou, M. F. Georgopoulos, D. E. Vatistas, I. Gonos, I. Stathopulos
In this paper calculations of lightning incidence on a bulk carrier ship model are presented with comparative application of various lightning attachment models and stroke current distributions. Depending on the ship structure, a lightning strike on coastal areas is expected approximately every two years. Regions exposed to lightning strikes were highlighted with application of the Rolling Sphere Method on the initial structure and after additional measures for the improvement of the external lightning protection system. Furthermore, impulse voltage experiments on a scaled down model of the above ship were conducted to assess the accuracy of lightning interception models. Lightning interception probability and proximity effects arise as factors that should be incorporated in shielding design.
{"title":"Investigation of lightning incidence on ships","authors":"E. Nicolopoulou, A. Alexandrou, M. F. Georgopoulos, D. E. Vatistas, I. Gonos, I. Stathopulos","doi":"10.1109/ICLP.2016.7791367","DOIUrl":"https://doi.org/10.1109/ICLP.2016.7791367","url":null,"abstract":"In this paper calculations of lightning incidence on a bulk carrier ship model are presented with comparative application of various lightning attachment models and stroke current distributions. Depending on the ship structure, a lightning strike on coastal areas is expected approximately every two years. Regions exposed to lightning strikes were highlighted with application of the Rolling Sphere Method on the initial structure and after additional measures for the improvement of the external lightning protection system. Furthermore, impulse voltage experiments on a scaled down model of the above ship were conducted to assess the accuracy of lightning interception models. Lightning interception probability and proximity effects arise as factors that should be incorporated in shielding design.","PeriodicalId":373744,"journal":{"name":"2016 33rd International Conference on Lightning Protection (ICLP)","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114729066","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 : 2016-09-01DOI: 10.1109/ICLP.2016.7791382
Y. Méndez, I. Acosta, J. Rodriguez, J. Ramirez, J. Bermudez, M. Martínez
The connection to ground of the negative or positive terminal of photovoltaic (PV) generators is a common practice to mitigate the effects of the potential induced degradation (PID), which is attributed to chemical reactions (ion's exchange) between the materials that constitute the PV-module during operation. Furthermore, the complex topology of a utility scale PV-plant, its dimensions and the stored energy in the central PV-inverter's DC-link open the hypothesis that overvoltages at the DC- and AC-side of the PV-plant may arise during transients caused by impulse currents. The objective of this publication is to explore the effects of this practice on the operation of utility scale MW-class PV-plants during transients caused by lightning.
{"title":"Effects of the PV-generator's terminals connection to ground on electromagnetic transients caused by lightning in utility scale PV-plants","authors":"Y. Méndez, I. Acosta, J. Rodriguez, J. Ramirez, J. Bermudez, M. Martínez","doi":"10.1109/ICLP.2016.7791382","DOIUrl":"https://doi.org/10.1109/ICLP.2016.7791382","url":null,"abstract":"The connection to ground of the negative or positive terminal of photovoltaic (PV) generators is a common practice to mitigate the effects of the potential induced degradation (PID), which is attributed to chemical reactions (ion's exchange) between the materials that constitute the PV-module during operation. Furthermore, the complex topology of a utility scale PV-plant, its dimensions and the stored energy in the central PV-inverter's DC-link open the hypothesis that overvoltages at the DC- and AC-side of the PV-plant may arise during transients caused by impulse currents. The objective of this publication is to explore the effects of this practice on the operation of utility scale MW-class PV-plants during transients caused by lightning.","PeriodicalId":373744,"journal":{"name":"2016 33rd International Conference on Lightning Protection (ICLP)","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115025227","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 : 2016-09-01DOI: 10.1109/ICLP.2016.7791444
Andri Haryono, N. Harid, H. Griffiths
This paper reports the results of computer simulations of a telecommunication tower located in a high flash density region and subjected to lightning strikes. This study is a response to lightning incidents which occurred within a few erected guyed towers in several locations in the region, and which resulted in severe damage to the low-voltage (LV) communication equipment connected to the tower. The aim is to elucidate the possible reasons that led to such damage and recommend protection measures to improve lightning performance. Using a realistic geometric representation of the tower, frequency-domain computations are carried out using frequencies representative of the typical lightning current, taking into account the propagation phenomena along the tower. A partial element equivalent circuit (PEEC) approach is used to compute the ground potential rise (GPR) at the surface of conductors and inductively-induced potentials and currents on adjacent LV communication cable. The results show that, depending on the shape of the lightning current, large potential differences in excess of the maximum withstand level of the insulation may occur between the cable core and cable sheath. Mitigating measures to reduce both the induced overvoltages and to improve grounding are suggested.
{"title":"Analysis of response of a guyed FM radio broadcasting tower subjected to a lightning strike","authors":"Andri Haryono, N. Harid, H. Griffiths","doi":"10.1109/ICLP.2016.7791444","DOIUrl":"https://doi.org/10.1109/ICLP.2016.7791444","url":null,"abstract":"This paper reports the results of computer simulations of a telecommunication tower located in a high flash density region and subjected to lightning strikes. This study is a response to lightning incidents which occurred within a few erected guyed towers in several locations in the region, and which resulted in severe damage to the low-voltage (LV) communication equipment connected to the tower. The aim is to elucidate the possible reasons that led to such damage and recommend protection measures to improve lightning performance. Using a realistic geometric representation of the tower, frequency-domain computations are carried out using frequencies representative of the typical lightning current, taking into account the propagation phenomena along the tower. A partial element equivalent circuit (PEEC) approach is used to compute the ground potential rise (GPR) at the surface of conductors and inductively-induced potentials and currents on adjacent LV communication cable. The results show that, depending on the shape of the lightning current, large potential differences in excess of the maximum withstand level of the insulation may occur between the cable core and cable sheath. Mitigating measures to reduce both the induced overvoltages and to improve grounding are suggested.","PeriodicalId":373744,"journal":{"name":"2016 33rd International Conference on Lightning Protection (ICLP)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129825923","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 : 2016-09-01DOI: 10.1109/ICLP.2016.7791490
M. Izadi, Mohd Zainal Abidin Ab Kadir, M. Hajikhani, C. Gomes
In this paper, an algorithm is proposed to evaluate a lightning location as well as the lightning current wave shapes at different heights along a channel using lightning measured magnetic fields at two stations. The proposed algorithm is based on the captured return stroke part of the magnetic fields directly in the time domain. The proposed method can support different engineering current models and can also be developed for different distances. The proposed method can be helpful for creating lightning location and lightning current data banks as it can estimate the full shape of the current as opposed to the usual methods used previously.
{"title":"Evaluation of lightning location and lightning current wave shape using measured lightning magnetic fields at two stations","authors":"M. Izadi, Mohd Zainal Abidin Ab Kadir, M. Hajikhani, C. Gomes","doi":"10.1109/ICLP.2016.7791490","DOIUrl":"https://doi.org/10.1109/ICLP.2016.7791490","url":null,"abstract":"In this paper, an algorithm is proposed to evaluate a lightning location as well as the lightning current wave shapes at different heights along a channel using lightning measured magnetic fields at two stations. The proposed algorithm is based on the captured return stroke part of the magnetic fields directly in the time domain. The proposed method can support different engineering current models and can also be developed for different distances. The proposed method can be helpful for creating lightning location and lightning current data banks as it can estimate the full shape of the current as opposed to the usual methods used previously.","PeriodicalId":373744,"journal":{"name":"2016 33rd International Conference on Lightning Protection (ICLP)","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130523535","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 : 2016-09-01DOI: 10.1109/ICLP.2016.7791508
S. Pastromas, Alkistis Papamikou, Georgios Peppas, E. Pyrgioti
The paper discusses the effect of the grounding resistance on the transient response of MV railway grid during lightning strikes. For study purposes were modelled the electrified railway MV grid (ERMV) that the Hellenic electromotive suburban railway makes use, including the masts, consoles, the rails and the overhead medium-voltage transmission grid of 25kV dedicated for this purpose. For the simulation of the understudied model time-domain solver was adopted in ATP-EMTP software. The model Volt-Time Curve is used for the modeling of the insulator, but it was necessary to create a new equation for the specific model, because of the short length of the insulator in such projects. Two types of lightning are used for the simulation purposes, for fast and slow signal, with current value in 100kA and one measurement in 30kA. For fast signal, the values of front and tail time are 1.2/50μs and for the slow signal 10/350μs. In addition, for the ground resistance: 10Ω, 70Ω and 245Ω are used.
{"title":"Investigation of grounding resistance effect on the MV grid of Hellenic electromotive railway during lightning strikes","authors":"S. Pastromas, Alkistis Papamikou, Georgios Peppas, E. Pyrgioti","doi":"10.1109/ICLP.2016.7791508","DOIUrl":"https://doi.org/10.1109/ICLP.2016.7791508","url":null,"abstract":"The paper discusses the effect of the grounding resistance on the transient response of MV railway grid during lightning strikes. For study purposes were modelled the electrified railway MV grid (ERMV) that the Hellenic electromotive suburban railway makes use, including the masts, consoles, the rails and the overhead medium-voltage transmission grid of 25kV dedicated for this purpose. For the simulation of the understudied model time-domain solver was adopted in ATP-EMTP software. The model Volt-Time Curve is used for the modeling of the insulator, but it was necessary to create a new equation for the specific model, because of the short length of the insulator in such projects. Two types of lightning are used for the simulation purposes, for fast and slow signal, with current value in 100kA and one measurement in 30kA. For fast signal, the values of front and tail time are 1.2/50μs and for the slow signal 10/350μs. In addition, for the ground resistance: 10Ω, 70Ω and 245Ω are used.","PeriodicalId":373744,"journal":{"name":"2016 33rd International Conference on Lightning Protection (ICLP)","volume":"12 3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130489187","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 : 2016-09-01DOI: 10.1109/ICLP.2016.7791345
H. Hayashiya, Keiichiro Hanaoka, K. Nishimura, Tomofumi Momose, Hideaki Takizawa, Takehiko Nakamura, Yusuke Yamamoto, Kohei Sakaguchi, S. Yasui
On August 17th, 2012, a diode rectifier at Nagano Traction Substation was broken. The broken rectifier was dismantled and investigated in detail and, as a result, it was estimated that the overvoltage caused by the thunder lightning caused the dielectric breakdown in the rectifier. To confirm the assumption of the broken process, the field measurement at Nagano Traction Substation and FDTD (finite-difference time-domain) calculation analysis at Nagoya Institute of Technology were carried out. As a result, it was indicated that the direct lightning to the elevated bridge over the substation caused the transient overvoltage of the grounding system of the substation and resulted in the breakdown within the rectifier. Because the concrete bridge pier is located adjacent to the substation, the surge voltage from the elevated bridge is able to influence on the potential of the substation mesh. In this paper, the investigation process to determine the cause of the trouble will be shown in detail.
{"title":"Cause investigation of diode rectifier trouble by lightning in traction substation","authors":"H. Hayashiya, Keiichiro Hanaoka, K. Nishimura, Tomofumi Momose, Hideaki Takizawa, Takehiko Nakamura, Yusuke Yamamoto, Kohei Sakaguchi, S. Yasui","doi":"10.1109/ICLP.2016.7791345","DOIUrl":"https://doi.org/10.1109/ICLP.2016.7791345","url":null,"abstract":"On August 17th, 2012, a diode rectifier at Nagano Traction Substation was broken. The broken rectifier was dismantled and investigated in detail and, as a result, it was estimated that the overvoltage caused by the thunder lightning caused the dielectric breakdown in the rectifier. To confirm the assumption of the broken process, the field measurement at Nagano Traction Substation and FDTD (finite-difference time-domain) calculation analysis at Nagoya Institute of Technology were carried out. As a result, it was indicated that the direct lightning to the elevated bridge over the substation caused the transient overvoltage of the grounding system of the substation and resulted in the breakdown within the rectifier. Because the concrete bridge pier is located adjacent to the substation, the surge voltage from the elevated bridge is able to influence on the potential of the substation mesh. In this paper, the investigation process to determine the cause of the trouble will be shown in detail.","PeriodicalId":373744,"journal":{"name":"2016 33rd International Conference on Lightning Protection (ICLP)","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127845551","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 : 2016-09-01DOI: 10.1109/ICLP.2016.7791517
Naoyoshi Tsutsui, Kazuo Yamamoto, Y. Kasai, N. Honjo, Keiichi Takahashi, Toshio Goda, H. Takagi, Y. Naito
Recently, lightning damage causing distress to wind turbine generation systems have been frequently reported. If these systems can be shut down before lightning strikes, potential secondary damage due to rotation can be prevented and damage can be mitigated. In shutting down systems in advance, it is necessary to know the probability of a lightning strike. We consider that potential differences in atmospheric electric fields are suitable for forecasting lighting strikes. In December 2014, we measured potential differences and lightning strikes on a wind turbine system using a Rogowski coil at one of the coasts of the Sea of Japan. In this paper, recommended potential differences are reported for shutting down wind turbine systems by comparing the loss of generated power incurred by shutting down and success in preventing damage based on the relation between the potential difference and actual lighting strikes.
{"title":"Study of wind turbine generation system shutdown using atmospheric electric field potential","authors":"Naoyoshi Tsutsui, Kazuo Yamamoto, Y. Kasai, N. Honjo, Keiichi Takahashi, Toshio Goda, H. Takagi, Y. Naito","doi":"10.1109/ICLP.2016.7791517","DOIUrl":"https://doi.org/10.1109/ICLP.2016.7791517","url":null,"abstract":"Recently, lightning damage causing distress to wind turbine generation systems have been frequently reported. If these systems can be shut down before lightning strikes, potential secondary damage due to rotation can be prevented and damage can be mitigated. In shutting down systems in advance, it is necessary to know the probability of a lightning strike. We consider that potential differences in atmospheric electric fields are suitable for forecasting lighting strikes. In December 2014, we measured potential differences and lightning strikes on a wind turbine system using a Rogowski coil at one of the coasts of the Sea of Japan. In this paper, recommended potential differences are reported for shutting down wind turbine systems by comparing the loss of generated power incurred by shutting down and success in preventing damage based on the relation between the potential difference and actual lighting strikes.","PeriodicalId":373744,"journal":{"name":"2016 33rd International Conference on Lightning Protection (ICLP)","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127898047","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 : 2016-09-01DOI: 10.1109/ICLP.2016.7791450
J. Montanyà, F. Fabró
Electromagnetic field from simulated double-headed mid-gap streamers is computed. The effect of the applied electric field is studied by considering electric fields higher than the conventional breakdown threshold ('overvoltage'). The obtained results show a 20 dB decay at ~3.8 GHz for conventional breakdown electric field, ~35 GHz for ambient electric fields five times the conventional breakdown and ~170 GHz for fields ten times the conventional breakdown electric field. The limitation in nature of the intense electric fields suggest further experiments using a radio receiver at frequencies of more than 10 GHz in order to investigate the origin of the detected x-rays in laboratory sparks.
{"title":"Electromagnetic radiation of simulated mid-gap streamers","authors":"J. Montanyà, F. Fabró","doi":"10.1109/ICLP.2016.7791450","DOIUrl":"https://doi.org/10.1109/ICLP.2016.7791450","url":null,"abstract":"Electromagnetic field from simulated double-headed mid-gap streamers is computed. The effect of the applied electric field is studied by considering electric fields higher than the conventional breakdown threshold ('overvoltage'). The obtained results show a 20 dB decay at ~3.8 GHz for conventional breakdown electric field, ~35 GHz for ambient electric fields five times the conventional breakdown and ~170 GHz for fields ten times the conventional breakdown electric field. The limitation in nature of the intense electric fields suggest further experiments using a radio receiver at frequencies of more than 10 GHz in order to investigate the origin of the detected x-rays in laboratory sparks.","PeriodicalId":373744,"journal":{"name":"2016 33rd International Conference on Lightning Protection (ICLP)","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126867267","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：