PBN(performance based navigation)飞行程序在国内运输机场应用广泛,PBN飞行程序设计的工作难点是最后进近航段障碍物评估,为了提PBN飞行程序设计的工作效率、降低出错率,本文将基于目前飞行程序设计常用的工作平台auto CAD,建立障碍...PBN(performance based navigation)飞行程序在国内运输机场应用广泛,PBN飞行程序设计的工作难点是最后进近航段障碍物评估,为了提PBN飞行程序设计的工作效率、降低出错率,本文将基于目前飞行程序设计常用的工作平台auto CAD,建立障碍物评估模型并研究开发能自动生成最后进近航段保护区、能自动进行障碍物评估的辅助软件,使用某机场数据进行测试,经过测试验证,此辅助软件的计算过程正确、计算结果的精度符合要求。展开更多
The conventional fault analysis method based on symmetrical components supposes that the three-phase parameters of un-transposed transmission line are symmetrical in case of fault. The errors caused by the method with...The conventional fault analysis method based on symmetrical components supposes that the three-phase parameters of un-transposed transmission line are symmetrical in case of fault. The errors caused by the method with the symmetrical distributed parameter circuit model as the equivalent circuit of the un-transposed ultra high voltage(UHV) transmission line were studied under both normal operation and fault,and the corresponding problems arising were pointed out. By contrast with electromagnetic transient and power electronics(EMTPE) simulation results with the asymmetrical distributed parameter circuit model of un-transposed line, it is shown that the conventional method cannot show the existence of negative and zero sequences before fault happening and there are many errors on voltage and current after fault happening which are different with fault types. The error ranges of voltage and current are 2.13%-81.13% and -7.82%- -86.15%, respectively.展开更多
In the long distance GIL under certain conditions, this paper researches and realizes detection of PD characters and accurate fault localization through UHF coupling sensors at different positions of the GIL pipeline....In the long distance GIL under certain conditions, this paper researches and realizes detection of PD characters and accurate fault localization through UHF coupling sensors at different positions of the GIL pipeline. The main methods for the detection are UHF signal amplitude difference （DOA） and time difference （TOF）. We analyze the localization error by using TE and TEM component and high order TE mode component in electromagnetic coaxial wave guide theory. Research and field test prove the DOA detection error can meet the requirements of real-time online diagnosis and for history tracking analysis. The error of TOF detection method can be controlled within 3% and can be applied to the site.展开更多
文摘PBN(performance based navigation)飞行程序在国内运输机场应用广泛,PBN飞行程序设计的工作难点是最后进近航段障碍物评估,为了提PBN飞行程序设计的工作效率、降低出错率,本文将基于目前飞行程序设计常用的工作平台auto CAD,建立障碍物评估模型并研究开发能自动生成最后进近航段保护区、能自动进行障碍物评估的辅助软件,使用某机场数据进行测试,经过测试验证,此辅助软件的计算过程正确、计算结果的精度符合要求。
文摘The conventional fault analysis method based on symmetrical components supposes that the three-phase parameters of un-transposed transmission line are symmetrical in case of fault. The errors caused by the method with the symmetrical distributed parameter circuit model as the equivalent circuit of the un-transposed ultra high voltage(UHV) transmission line were studied under both normal operation and fault,and the corresponding problems arising were pointed out. By contrast with electromagnetic transient and power electronics(EMTPE) simulation results with the asymmetrical distributed parameter circuit model of un-transposed line, it is shown that the conventional method cannot show the existence of negative and zero sequences before fault happening and there are many errors on voltage and current after fault happening which are different with fault types. The error ranges of voltage and current are 2.13%-81.13% and -7.82%- -86.15%, respectively.
文摘In the long distance GIL under certain conditions, this paper researches and realizes detection of PD characters and accurate fault localization through UHF coupling sensors at different positions of the GIL pipeline. The main methods for the detection are UHF signal amplitude difference （DOA） and time difference （TOF）. We analyze the localization error by using TE and TEM component and high order TE mode component in electromagnetic coaxial wave guide theory. Research and field test prove the DOA detection error can meet the requirements of real-time online diagnosis and for history tracking analysis. The error of TOF detection method can be controlled within 3% and can be applied to the site.
