Results 1 to 10 of about 6,493 (111)

新能源并网逆变器控制策略研究综述与展望 [PDF]

open access: yes全球能源互联网, 2021
随着风电和光伏等新能源发电系统渗透率的不断提高,电网呈现出弱电网甚至极弱电网特性,给新能源并网发电系统稳定和高效运行带来了严峻挑战。通过回顾现有典型的新能源并网逆变稳定控制策略等方面的成果,总结了电流源模式、电压源模式以及双模式控制的基本原理和研究现状,并指出基于锁相环控制的电流源模式并网虽然能够保证强电网下的系统稳定性和功率控制快速性等,但是此类控制方式在稳定性、系统电压和频率调整等方面有诸多局限,难以适应新能源发电单元高比例接入的场景。基于功率自同步控制的电压源模式控制能够为电压和频率提供支撑 ...
张兴   +5 more
doaj   +1 more source

Research on Protection Scheme of DC Microgrid Integrated with Fault Current Limiting Control Technology [PDF]

open access: yes, 2023
[Introduction] With the development of new loads, such as distributed power sources and electric vehicles, DC(Direct Current) microgrids have the advantages of fewer commutation links and lower system losses than AC(Alternating Current) microgrids, and ...
Bingyao ZHENG   +6 more
core   +1 more source

Research on the Interaction Between Multi-Circuit Shared HVDC Grounding Electrodes [PDF]

open access: yes, 2023
[Introduction] Unlike the independent grounding electrode, shared earth electrode is connected to multiple DC (Direct Current) systems, and its parameters and operation mode need to be determined by each system connected to it.
Wen WANG, Yu LIU
core   +1 more source

Research on lightning transient distribution characteristics of cable-stayed bridges [PDF]

open access: yes, 2023
Bridges are usually located at the junction of land and water, where the surrounding area is open terrain, making them to be easily damaged by lightning strikes.
Dajun XU   +4 more
core   +1 more source

试析超高层建筑电气工程防雷接地的对策

open access: yes, 2022
常规的防雷电接地系统设计中,由于其避雷区较窄不能适应高层建筑物的雷击要求,所以进行了关于该技术的探讨。在此基础上,采用了防雷接地网和地基接地网的排布,电气工程的避雷接闪装置的选用,从而达到防雷的目的。经比较试验,表明此方案能较好地拓宽电网的防雷区保证电网的正常运营。
王 麒锦
core   +1 more source

基于单片机的LED智能照明系统 [PDF]

open access: yes, 2017
本文在总结了前人LED的基础上,利用单片机智能控制的方法研究智能LED的设计和制备,利用色度学三基色配色原理,通过更改三基色LED的电流大小实现整体LED系统的调光和调色,系统可实现亮度20%-100%的调节,实现全彩调节,满足人们的多样化照明需求;同时可通过手机APP利用红外技术实现LED的无线遥控 ...
曹文越
core   +1 more source

接地网形式对近水源区杆塔接地网外延降阻影响

open access: yesDianci bileiqi, 2023
为研究雷击电力杆塔时杆塔接地网降低接地电阻的效果,建立近水源平原和山区的单桩塔接地网和四桩塔接地网模型,计算不同土壤电阻率、电流频率下接地网形式对近水源区杆塔接地电阻的影响,并对比分析平原和山区地势条件下杆塔接地网形式的最优方案。仿真结果表明:接地网的接地电阻随着土壤电阻率和电流频率增大而升高。对于近水源的平原地区,单桩塔“米”字型接地网在单桩塔中降阻效果最显著,以单边外延接地网为比较基准,在工频和高频条件下的平均降阻效率分别为64.49%和76.15 ...
董贯雷   +5 more
doaj  

基于地电位均布的共享铁塔接地网设计方案

open access: yesDianci bileiqi, 2022
共享铁塔中移动基站的接地标准较为苛刻,需要对传统输电铁塔接地网进行改造以满足基站接地要求。笔者采用场路结合的方法,对接地导体进行分段处理,计算各分段导体的自电阻和互电阻,推导了共享铁塔接地网地电位的求解公式,进而判断接地网地电位的均匀程度。参照现有电力与通信的接地标准,提出了共享铁塔接地网的设计思路以及4种设计方案。计算结果表明,网状结构加垂直接地极的接地网设计方案可保证地电位分布最均匀,最大地电位梯度相比于简单扩大接地网面积的设计方案降了43.83%。
匡宇来   +4 more
doaj  

Quality evaluation of trial operation of the Jiangsu early warning network [PDF]

open access: yes
This article evaluates the continuous operation rate, station noise levels and event waveform quality within the Jiangsu early warning station network system.
Chi Yang   +4 more
core   +1 more source

DBX mail file parsing based on COM technology [PDF]

open access: yes, 2008
电子邮件客户端Outlook Express下保存的邮件数据文件,蕴藏着丰富的个人信息,挖掘分析其中的有用线索已成为计算机调查取证的重要手段和研究方向,而首要条件就是需要对这些经过编码的数据文件进行解析,将所有的邮件信息还原出来。针对此问题,提出了一种利用Outlook Express提供的COM组件接口对这些邮件数据文件直接进行解析处理的方法,避免了研究其编码及内部逻辑架构的繁琐。The E-mail data files kept by Outlook Express (OE) contain ...
吴顺祥   +3 more
core  

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