Results 1 to 10 of about 5,641 (169)
Power-Line Extraction Method for UAV Point Cloud Based on Region Growing Algorithm [PDF]
, 2023 [Introduction] Since the power line has the characteristics of long transmission distance and a complex spatial environment, the UAV LiDAR point cloud technology can completely and efficiently obtain the geometric information of the power line and its ...
Wei WU, Xingyi LI, Zhiyao ZHAO
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全球能源互联网, 2021 风电场、光伏电站和储能系统的容量优化规划是降低风光储多能源混合系统成本、保证系统可靠性的有效措施之一。依托山体的重力储能，可以风光储多能源混合系统中风电场容量、光伏电站容量和储能系统容量为决策变量，建立以系统总成本最小和包括风光互补特性、供电自给损失率及风光储多能源混合系统贡献率等因素的综合指标最优为目标函数的多目标容量优化规划模型，并利用多目标自适应混沌粒子群算法求解模型。基于此，考虑不同规划偏好，利用逼近理想解排序法对帕累托前沿进行排序，得到不同规划偏好下的最优规划方案。另外 ...
刘志刚 +7 more
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全球能源互联网, 2019 由于柔直电网“隔离”了频率信号，互联多区域协同调频问题亟待研究。现有研究大多利用换流站的下垂控制以及直流电压偏差实现频率信号的传递，但忽略了风电集群接入后由风电功率正常波动引起的直流电压偏差干扰，可能导致风电集群在无需调频时频繁地调整出力。对此，提出了基于直流电压偏差及其特征量的多区域协同调频策略，分别针对电网频率偏移和风电功率波动两种场景提取直流电压偏差特征量，包含电压变化量、电压变化率和滤波后的电压分量幅值3个特征，并基于二者的差异设置换流站启动下垂控制的判据。仿真结果验证了所提方法的有效性。
崔阳 +5 more
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Research on Lightning Performance and Protective Measures of ±800 kV UHVDC Power Transmission Line [PDF]
, 2023 [Introduction] Lightning strike is the primary cause of failures of ±800 kV UHVDC power transmission lines, and the lightning protection assessment of power transmission lines is critical to the safe and stable operation of the system.
Youjun GONG, Zhiwen HE, Ziwei YAN
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Acupuncture for Spasticity after Stroke: A Systematic Review and Meta-Analysis of Randomized Controlled Trials [PDF]
, 2015 The aim of this systematic review was to determine how effective acupuncture or electroacupuncture (acupuncture with electrical stimulation) is in treating poststroke patients with spasticity. We searched publications in Medline, EMBASE, and the Cochrane
Euiju Lee +6 more
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Research Progress of Galloping of Overhead Iced Transmission Lines [PDF]
, 2023 [Introduction] The galloping of transmission lines will lead to trip, worn hardware, broken insulator string, damaged tower-arm and other accidents. In serious cases, collapsed tower accidents may occur.
Guangyun MIN, Xiaohui LIU, Xin ZHAO
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Kongjian kexue xuebao, 2023 卫星散射计通过测量海表粗糙度反演全球海面风场。对于Ku波段散射计，海表粗糙不仅和海面风场相关，还受海表温度的二阶效应调制。定量研究了海表温度对中法海洋卫星（CFOSAT）散射计（CSCAT）反演风速和后向散射测量的影响。结果表明，CSCAT两种极化方式测量的后向散射系数都会受到海表温度的影响，但是垂直极化中低入射角（θ < 36°）测量的后向散射系数几乎不随温度变化。因此CSCAT的风速偏差也随海表温度的变化而变化，且随着入射角的增大和风速的减小，海表温度对风速偏差的影响程度增大 ...
赵 晓康 +3 more
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Dianci bileiqi, 2023 台风作为一种非良态的旋转风，常导致近海区域500 kV输电线路转角塔跳线发生风偏跳闸。本研究首次提出一种变径结构的500 kV转角塔跳线串用固定式防风偏复合绝缘子，对绝缘子技术参数、结构型式、材料选择、连接金具及附件、生产工艺等方面进行系统分析，通过建立有限元模型对防风偏复合绝缘子应力荷载特性进行仿真，对试品进行了机械及电气性能试验，证明产品的可靠性。考虑防风偏绝缘子对横担端部产生过大荷载的不利因素，提出了在挂线角钢中部增设两榀支撑桁架的优化布置型式，调整挂点传力途径、增强挂线角钢抗扭能力。研究表明 ...
徐福聪 +6 more
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中西医结合护理, 2021 This paper introduced the current status of clinical application of Traditional Chinese Medicine (TCM) collapse therapy in the treatment of hemiplegia after stroke, and summarized the advance of TCM collapse therapy and its clinical application with ...
ZHANG Nannan (张楠楠) +4 more
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From demonstrative to definite and beyond: the case of nage in spoken Taiwan Mandarin
Faits de Langues, 2014 When demonstrative pronouns undergo grammaticalization, they have regularly been shown to evolve into definite or specific articles (Lehmann 2002, De Mulder & Carlier 2001). In a synchronic perspective, it has also been shown that for some languages, demonstrative determiners are not restricted to deictic or anaphoric functions, but may extend their ...
openaire +3 more sources