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关于电力系统失稳判据病态研究的评述 被引量:2
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作者 吕睿 薛禹胜 +1 位作者 黄天罡 薛峰 《电力系统自动化》 EI CSCD 北大核心 2022年第18期169-178,共10页
电力系统同步稳定性的分析,必须基于系统受扰轨迹,并从中提取定性或定量的知识。扩展等面积准则(EEAC)证明,互补群映像轨迹上出现动态鞍点(DSP)是拟哈密顿系统失稳的充要条件,而该点的动能则反映了系统的不稳定程度。但是,如果映像系统... 电力系统同步稳定性的分析,必须基于系统受扰轨迹,并从中提取定性或定量的知识。扩展等面积准则(EEAC)证明,互补群映像轨迹上出现动态鞍点(DSP)是拟哈密顿系统失稳的充要条件,而该点的动能则反映了系统的不稳定程度。但是,如果映像系统在DSP附近的时变性太强,则系统在经过该点后可能重返稳定域。这种被称为病态DSP(IDSP)的现象,与Lorenz奇怪吸引子类似,都是复杂性研究中的核心问题,是在3维以下的非线性系统中观察不到的涌现(emergence)现象。IDSP符合DSP的定义,但因该映射系统的强时变性,使已经发生滑步的系统又被拉回了同步而得名。若为了减少计算量而提前终止积分,则必须同时验证对应时段内的时变性不能太强,以免将稳定算例误判为失稳。针对失稳轨迹提前终止积分的各种失稳判据,如EEAC的DSP判据、相平面轨迹的拐点判据、由加速度与速度组成的扩展相平面轨迹的切线判据等,从理论上比较了各判据的强壮性,也给出大量仿真结果进行了验证。 展开更多
关键词 运动系统稳定性 扩展等面积准则(EEAC) 时变性病态 相轨迹 凹凸性 提前终止积分
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Airborne Pollen Grains Of Afyon, Turkey 被引量:3
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作者 Adem BICAKCI 1, Süheyla ERGUN 2, Sevcan TATLIDIL 1, Hulusi MALYER 1, Sabri ?ZYURT 2, Ahmet AKKAYA 3, Nihat SAPAN 5 Department of Biology, Faculty of Science, University of Uludag, Bursa, Turkey 2. Department of Biology, Faculty of Science, University of Afyon Kocatepe, Afyon Turkey +1 位作者 3. Department of Pulmonology, Faculty of Medicine, University of Süleyman Demirel, Isparta, Turkey 4. Division of Pediatric Allergy, Faculty of Medicine, University of Uludag, Bursa, Turkey) 《Acta Botanica Sinica》 CSCD 2002年第11期1371-1375,共5页
The airborne pollen grains of Afyon have been studied for a two_year period (1999-2000) with a Durham sampler. A total of 14 367 pollen grains belonging to 40 taxa have been identified and recorded with some unidentif... The airborne pollen grains of Afyon have been studied for a two_year period (1999-2000) with a Durham sampler. A total of 14 367 pollen grains belonging to 40 taxa have been identified and recorded with some unidentified ones. Of them, 6 732 were identified in 1999 and 7 635 in 2000. Of the total pollen grains, 69.67% were arboreal, 26.64% non_arboreal and 3.68 % unidentified. The majority of the investigated pollen grains were from Pinus, Gramineae, Cupressaceae, Platanus , Chenopodiaceae/Amaranthaceae, Quercus, Ailanthus, Moraceae, Juglans , Salix, Cedrus and Rosaceae. The highest level of pollen grains was in May. 展开更多
关键词 TURKEY Afyon pollen calendar pollen grains
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