模块化多电平换流器 - Open Access .click

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全球能源互联网, 2018
低全桥子模块配比的混合式模块化多电平换流器（modular multi-level converter，MMC）应用于高低阀组拓扑结构的特高压柔性直流系统时，在单阀组在线投入/退出过程中存在半桥子模块持续充/放电引起的子模块电压不均衡问题，严重影响系统安全。通过详细的理论分析，指出阀组投入/退出过程中桥臂电流不存在过零点是导致半桥子模块持续充放电问题的本质原因。为此提出了基于环流注入的单阀组投/退过程中的均压控制，在阀组投退期间控制MMC产生一定的相间环流，人为创造正负交替的桥臂电流，为半桥子模块充 ...
杨美娟 +5 more
doaj +1 more source

无闭锁柔性直流输电系统样机实验研究 [PDF]

全球能源互联网, 2018
针对现有的半桥型MMC难以应对直流故障，阻断型MMC直流故障时需要闭锁换流器的缺陷，提出了一种无闭锁柔性直流输电系统。实验展示了无闭锁柔直的直流故障无闭锁穿越、降直流电压运行、直流电压极性反转等能力，并进一步开展了无闭锁柔直互联传统柔直，以及无闭锁柔直串联构成阀组串联结构的实验研究。实验验证了无闭锁柔直优异的控制性能。
林卫星 +5 more
doaj +1 more source

双极柔性直流电网短路电流暂态特性分析 [PDF]

全球能源互联网, 2018
架空线柔性直流电网是实现大规模可再生能源广域协调互补和可靠送出的有效解决方案，是未来高压大容量柔性直流输电的重要应用方向。直流线路短路电流是柔性直流电网中换流阀、直流断路器及电抗器等关键主设备参数选取的重要依据之一。通过建立双极柔性直流电网单个换流站在直流线路不同短路故障类型下的等效电路数学模型，构建了故障时刻双极柔性直流电网等效电路网络模型，提出了一种适用于双极柔性直流电网的单极接地、单极接中性线及双极短路的暂态短路电流定量分析方法，实现了双极柔性直流电网直流线路任意故障类型 ...
裴翔羽 +5 more
doaj +1 more source

基于快速排序法的MMC电容电压均衡控制策略 Capacitance-Voltage Balancing Control Method for the Submodule of Modular Multilevel Converter Based on the Rapid Sequencing Method

, 2017
随着基于模块化多电平换流器的柔性直流输电工程容量和直流侧电压等级的提高，对子模块电容平衡控制提出了更高的要求。为降低众多子模块均压排序的计算量及MMC开关损耗，提出一种基于分治思想和快速排序算法的改进子模块电容电压均衡控制策略。根据每个控制周期的投切控制指令和桥臂充放电状态，将待投切子模块电容电压值进行两轮分组，然后根据具体投切数量在最小范围内选取与额定电容电压差值较大的子模块进行投切操作，从而避免对所有子模块进行重复排序。最后，通过在PSCAD/EMTDC中搭建MMC模型对本文方法进行了验证 ...
唐茂林 +5 more
semanticscholar +1 more source

Application of Rigid-flexible Management in Digital Electronic Technology Experiment Lab

DEStech Transactions on Social Science Education and Human Science, 2019
This paper tells the specific application and actual effect of rigid-flexible management (short for the rigid management and flexible management in this paper) of experiment teaching and management in the digital electronic technology of our University ...
Li-mei Wang
semanticscholar +1 more source

[A method for determining spatial resolution of phantom based on automatic contour delineation]. [PDF]

Sheng Wu Yi Xue Gong Cheng Xue Za Zhi
Liu Y, Sun M, Zhang H, Liu H.
europepmc +1 more source

[Cross-session motor imagery-electroencephalography decoding with Riemannian spatial filtering and domain adaptation]. [PDF]

Sheng Wu Yi Xue Gong Cheng Xue Za Zhi
Pan L, Sun X, Wang K, Cao Y, Xu M, Ming D. +5 more
europepmc +1 more source

[A low-dose CT image restoration method based on central guidance and alternating optimization]. [PDF]

Nan Fang Yi Ke Da Xue Xue Bao
Zhang X, Wang H, Zeng D, Bian Z.
europepmc +1 more source

[Research on a portable electrical impedance tomography system for evaluating blood compatibility of biomaterials]. [PDF]

Sheng Wu Yi Xue Gong Cheng Xue Za Zhi
Peng P +7 more
europepmc +1 more source

[Design and validation of an automated testing system for essential performance parameters of ventilators]. [PDF]

Sheng Wu Yi Xue Gong Cheng Xue Za Zhi
Li Y +5 more
europepmc +1 more source

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