نتایج جستجو برای: lightning

تعداد نتایج: 6387  

2015
Yiming Ji Jinliang He

Recently a new concept of umbrella–ladder combination system to exploit the high altitude wind energy has been proposed. In this system the polyethylene polymer transmission tether plays an important role as the connection between the high altitude wind power absorber and the ground station. To make the concept practical, whether the tether would lead lightning to the ground station is one of t...

2017
Li Zhang Shengwei Fang Guozheng Wang Tong Zhao Liang Zou

In recent years, with the rapid development of offshore wind turbines (WTs), the problem of lightning strikes has become more and more prominent. In order to reduce the failure rate caused by the transient overvoltage of lightning struck offshore WTs, the influencing factors and the response rules of transient overvoltage are analyzed. In this paper, a new integrated electromagnetic transient m...

Abstract— In this paper, input impedance of a vertical rod under lightning stroke is first computed by applying the method of moments (MoM) on the Maxwell’s equations. The circuit model is then achieved through applying modified vector fitting (MVF) on the computed input impedance. After then the equivalent circuit is again extracted for a few values of soil conductivity and rod radius. Finally...

2003
Steven J. Goodman

How might lightning measurements be used to improve short-term (0-24 hr) weather forecasting? We examine this question under two different prediction strategies. These include integration of lightning data into short-term forecasts (nowcasts) of convective (including severe) weather hazards and the assimilation of lightning data into cloud-resolving numerical weather prediction models. In each ...

2013
Li Chunhua Wang Weiran Su Jie Li Tao

According to the physical process of discharge development of insulator that is struck by lightning, the lightning flashover model for quadruple-circuit transmission line with dual voltage 220kV/110kV in same tower is established basing on EMTP. The actual evaluation index of lightning protection performance is adopted with the consideration of influence of system voltage. The characteristics o...

2002
Wenyi Hu Steven A. Cummer Walter A. Lyons Thomas E. Nelson

[1] The transient ELF ( 50–5000 Hz) magnetic field radiated by lightning discharges across North America was continuously measured at Duke University during the summer of 2000. In total, 881 sprite-associated lightning discharges over 17 days were analyzed. We report in detail on 76 sprites for which we could reliably determine the lightning charge moment change from the ELF data at the time of...

Gas-insulated substations (GIS) have different specifications in proportion to air-insulated substations. Transformer failures related to lightning and switching are often reported in the gas insulated substation (GIS). This problem is the voltage magnifications due to reflections of switching and lightning surges at various junctions within the GIS. thereby overvoltages in GIS are more importa...

Journal: :iJOE 2015
Ji Shen Qiuwen Zhang

Lightning detection data is a kind of distributed information with high real-timeliness. After the lightning events are detected by the lightning detection network, the original detection data need to be collected and concentrated rapidly and timely for unified management and processing. In this paper, an online monitoring and transmission system for lightning detection information is presented...

2007
M A Omidiora M Lehtonen

Overhead distribution lines are prone to lightning overvoltages due to their configurations and characteristics. Metal Oxide Varistor (MOVs) arresters for many years have proven to be more advantageous than others arresters in lightning surge protection; therefore it is worthwhile to continually assess the behavior and performance of these arresters to different kind of overvoltages caused by l...

2009
Mark DeMaria Robert T. DeMaria

The next generation geostationary satellite system starting with GOES-R will include a geostationary lightning mapper (GLM). The GLM will provide nearly continuous times and locations of total lightning with an accuracy of about 10 km over most of the field of view of GOES-east and –west. This coverage will include nearly all of the regions where tropical cyclones occur in the Atlantic and nort...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید