Results 11 to 20 of about 4,448 (115)

用于区域间电网互联的新型 VSC 虚拟同步技术 [PDF]

open access: yes全球能源互联网, 2020
传统基于锁相环(phase lock loop,PLL)电网跟踪型控制在电网短路比(short circuit ratio,SCR)较低或PLL带宽较高情况时,给电力系统引入负阻尼导致系统不稳定。为此,提出了一种不依赖PLL的用于区域间电网互联的新型电压源换流器(voltage source converter,VSC)虚拟同步控制。首先,构造VSC直流电压与受端系统频率间的下垂特性,当受端电网受扰后,受端换流器可为系统提供惯量支撑。其次,测量送端电压波动与直流电流波动可计算受端交流系统的频率扰动 ...
刘宏伟   +5 more
doaj   +1 more source

成都露天音乐广场索网结构控制技术研究

open access: yesJianzhu Gangjiegou Jinzhan, 2021
以成都露天音乐广场主舞台索网工程为研究对象,从索网工程施工难点、质量控制方法、施工过程等几个方面进行了分析;该工程涉及了索网结构尺寸、组装、提升、张拉等方面的质量控制措施和原则。同时,针对受限空间索网施工难度大、周期长的问题,提出了合理的索网展铺和提升方法;并采用有限元分析与监控监测相结合的方式来保证索网施工的安全与质量。研究结果显示,索网结构成型后,索力大小以及结构主要控制点位移变化值均满足设计要求,双曲拱线性控制良好,索网施工效率提高了26.7 ...
高翔, 姜友荣, 郭浩, 李国明
doaj  

Grid-connected control strategy of GFM inverter in solar-powered ship photovoltaic system [PDF]

open access: yes
Objective The paper aims to solve the problem of the overall stability of the ship's power system being reduced due to the use of grid-following (GFL) control for grid connection in existing solar ship photovoltaic (PV) power generation systems ...
Chunhua ZHAO   +2 more
core   +1 more source

Local Government Performance, Cost‐Effectiveness, and Use of the Web: An Empirical Analysis

open access: yesPolicy &Internet, Volume 11, Issue 4, Page 480-507, December 2019., 2019
This article empirically assesses the relationship between government use of the web, service performance, and cost‐effectiveness. It tests and challenges the assumption, prevalent in government thinking and in the Digital Era Governance (DEG) quasi‐paradigm, that the delivery of web‐based public services is associated with better outcomes.
Tom Nicholls
wiley   +1 more source

辅助风电并网的构网型储能控制策略研究

open access: yesGaoya dianqi, 2023
随着能源转型的深入,风光等可再生能源大规模替代传统能源发电并网,电力系统结构发生很大的变化,导致电网惯性变低、稳定性变弱。另外,风力发电功率的波动性将导致电力系统调度困难。因此,在风电并网系统中增加构网型储能系统,并给出构网型储能系统的控制策略,进而围绕风电并网的稳定性以及电压跌落故障,对构网型储能系统增加前后风电并网波形进行对比分析,验证了构网型储能系统可以大大提高风电并网的稳定性,并且对电压跌落故障有很好的抑制作用。
杨本星, 王伟, 杨明轩, 柳涛
doaj  

International clinical practice recommendations on the definition, diagnosis, assessment, intervention, and psychosocial aspects of developmental coordination disorder – Chinese (Mandarin) translation

open access: yesDevelopmental Medicine &Child Neurology, Volume 61, Issue 3, Page E1-E35, March 2019., 2019
目的 本国际临床指南由欧洲残疾儿童学会(the European Academy of Childhood Disability,EACD)牵头制定,旨在解决发育性协调障碍(developmental coordination disorder,DCD)的定义、诊断、评估、干预以及与社会心理方面的临床应用关键问题。 方法 本指南针对五个领域的关键问题,通过文献综述和专家团队的正式讨论达成共识。为保证指南的循证基础,以“机制”、“评估”和“干预”为检索词, 对2012年更新以来提出的最新建议以及新增的“社会心理问题”和“青少年/成人”为检索词进行检索。根据牛津大学循证医学中心证据等级 (证据水平 [level of evidence, LOE]1–4) 将结果进行分类,最终转化为指南建议。并由国际 ...
Jing Hua   +6 more
wiley   +1 more source

Internal physiological drivers of leaf development in trees: Understanding the relationship between non‐structural carbohydrates and leaf phenology

open access: yesFunctional Ecology, EarlyView.
Read the free Plain Language Summary for this article on the Journal blog. Abstract Plant phenology is crucial for understanding plant growth and climate feedback. It affects canopy structure, surface albedo, and carbon and water fluxes. While the influence of environmental factors on phenology is well‐documented, the role of plant intrinsic factors ...
Yunpeng Luo   +8 more
wiley   +1 more source

Contrasting light demands determine the coordination of plants' non‐structural carbohydrates and economic strategy over the range of solar spectral composition

open access: yesFunctional Ecology, Volume 40, Issue 2, Page 534-552, February 2026.
Read the free Plain Language Summary for this article on the Journal blog. Abstract Non‐structural carbohydrates (NSC) are critical mediators of plant adaptation to fluctuating light environments. They are tightly coordinated with plant economic strategy, that is, leaf economics spectrum (LES) and root economics spectrum (RES).
Lulu Xie   +6 more
wiley   +1 more source

Effects of landscape fragmentation on floodplain fishes as revealed by species–habitat networks

open access: yesConservation Biology, Volume 40, Issue 1, February 2026.
Abstract How species interact with habitat patches is influenced primarily by habitat configuration (e.g., connectivity) and species’ functional traits. As levels of fragmentation increase, identifying the intricate connections between these components is crucial for biodiversity conservation.
Chen Zhang   +8 more
wiley   +1 more source

基于VSG技术的风——光—储系统自适应调频控制策略研究

open access: yesGaoya dianqi, 2023
“双碳”目标的实施和新型电力系统的建设极大推动了可再生能源并网发电进程,电力系统的结构也因此发生巨大改变。由于可再生电源无法参与电网的惯性和阻尼调节过程,并网后极易造成电网频率失调、负载功率失稳现象。因此,文中提出一种基于虚拟同步机(virtual synchronous generator,VSG)技术的风—光—储系统自适应调频控制策略。首先,在风—光—储VSG系统结构基础上建立数学模型,并分析VSG技术调频特性;然后,综合考虑风电、光伏发电曲线 ...
郑云平, 亚夏尔·吐尔洪
doaj  

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