Results 21 to 30 of about 17,121 (168)
The study of bidirectional DC-DC converter in the DC microgrid [PDF]
, 2016 作为新能源的有效利用方式之一的直流微电网没有无功功率的损耗，不需要跟踪频率和相位，可靠性和可控性有较大程度的提高，更适合分布式能源的接入和应用。双向DC-DC变换器承担着母线与储能之间能量双向流动的重要作用。同时，它还可以作为直流微电网之间的互联元件，具有十分重要的研究价值。 本文针对全桥拓扑结构的双向DC-DC变换器展开较为深入的研究。 首先，详细分析了在移相控制方式下，双向DC-DC变换器的在降压方向和升压方向的工作原理及零电压开关（ZVS，Zerovoltageswitching）的具体过程 ...
纪承承
core
High Voltage Crossing Strategy of Wind Farm Considering Active and Reactive Coordinated Recovery [PDF]
ObjectivesTo address the serious high voltage ride-through (HVRT) problem faced by wind farms as a result of the large voltage surge at the grid-connected point after a DC fault, a recovery mechanism of “active priority balancing - reactive power dynamic
HAN Lu +4 more
core +1 more source
Laser‐Driven Halide Exchange and High‐Resolution Multicolor Patterning of Perovskite Films
Rare Metals, EarlyView.ABSTRACT Translating the excellent properties of metal halide perovskites (MHPs) into practical flexible optoelectronic devices requires high‐resolution multicolor patterning techniques that are compatible with post‐fabrication processing. However, such a capability has remained elusive.
Shu Yang +6 more
wiley +1 more source
Research and application on induction heating technology based on the technique of quasi-resonant [PDF]
, 2016 感应加热作为新兴学科，在近30年来得到了真正应用，顾名思义，感应加热是利用电磁感应的原理使被加热的对象内部产生涡流，然后利用涡流做功来达到加热的目的。由于感应加热具有加热效率高、速度快、可控性好并且容易实现机械化、自动化的优点，已在加热、铸造、焊接、热锻和表面热处理等行业得到广泛的应用。 本文首先介绍了感应加热技术在国内外的发展现状和未来发展趋势，紧接着介绍了电磁感应加热技术的基本原理和实现方式。详细分析了串、并联谐振逆变电路的优缺点，并对各种逆变器进行比较 ...
戴立业
core
柔性直流并入城市电网后对换流站近区短路电流的影响研究 [PDF]
, 2023 大型城市供电电网短路电流已经接近断路器遮断容量，柔性直流接入系统后，会在故障期间提供工作电流，导致交流系统短路电流超标，柔性直流输送功率受限。从柔性直流内外环控制方式及交流系统短路电流计算原理出发，分析得出柔性直流短路电流的幅值和相位对并网点的短路电流影响均较大，其中幅值受外环电流限幅环节的影响易于控制，因此需着重对相位进行控制。基于此提出了一种降低柔性直流输电换流站两端PCC点短路电流的控制策略。以厦门柔性直流工程为例，开发了交直流混合模型，与实测波形对比验证了模型的正确性。通过对不同类型故障下 ...
寇龙泽, 朱琳, 范征, 谷怀广
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High‐Brightness Delayed Imaging Realized by Embedding Zinc Gallate Nanocrystals Into Glass
Rare Metals, EarlyView.ABSTRACT X‐ray delayed imaging technology leverages an “irradiation‐storage‐thermally stimulated readout” mode, demonstrating unique advantages in intermittent monitoring scenarios such as high‐temperature/high‐radiation environments. This typically requires materials combining abundant carrier‐trapping energy levels with structural thermostability ...
Jun‐Xiao Wu +6 more
wiley +1 more source
Gaoya dianqi, 2021 单芯电缆的结构参数和运行环境影响都会导致电缆的无功损耗变化。为了探究单芯电缆结构和运行环境对电缆无功损耗的影响,文中从电缆内部结构出发,建立了电缆等效电路模型。通过分析电缆内部无功损耗形式,研究了单芯电缆在特殊工况下的无功损耗变化情况。结果表明:单端接地电缆内部损耗以容性无功损耗为主;电缆电压等级越高时,输送一定功率的极限传输距离反而越短,并给出了66、110、220、330、500 kV电缆的极限传输距离;电缆内部进水后容性无功损耗会增大10%～30%,电压等级越高或者电缆截面积越大 ...
李瑞芳 +5 more
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Research on Tidal Optimization of Voltage Overrun Problem in Photovoltaic Distribution Network With Electrical Energy Router [PDF]
ObjectivesWith the access of high-penetration distributed photovoltaic to the distribution network, the problems of power back-feeding and voltage overrun become more and more serious.
FENG Zining +3 more
core +1 more source
Electrolyte With Functionalized Boron Nitride Nanosheets for Dendrite‐Free Lithium Metal Anodes
Rare Metals, EarlyView.ABSTRACT Lithium metal batteries (LMBs) are regarded as promising candidates for the next‐generation high‐energy‐density storage systems due to their unparalleled theoretical energy density and low redox potential. However, the commercialization of LMBs is tremendously plagued by the barbaric growth of lithium dendrite and the intricate decomposition ...
Ji Zhou +5 more
wiley +1 more source
Gaoya dianqi, 2017 针对变压器的直流偏磁问题,分析了特高压变压器直流偏磁时无功损耗的响应机理,给出无功损耗计算方法,进行无功损耗特性分析。采用增加串联电阻的方法,提高计算电流中直流分量的计算精度。结合电压补偿,消除增加串联电阻后导致的电压下降问题。根据特高压变压器的实际参数,建立变压器的场路耦合模型,进行特高压变压器不同直流偏磁电流下的仿真计算。研究表明,变压器直流偏磁时,励磁电流波形严重畸变。随着直流偏磁电流的增加,特高压变压器的空载无功功率逐渐增加,直流偏磁电流超过一定范围后 ...
王泽忠, 谭瑞娟, 刘连光, 邓涛
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