Results 41 to 50 of about 9,516 (147)
Design of Photovoltaic Tracking System Based on Fourier Fitting [PDF]
[Introduction] In order to improve the power generation efficiency of photovoltaic brackets, the research and design focus is on a photovoltaic tracker based on Fourier fitting algorithm for apparent solar motion trajectory.
Jianyun ZHANG +3 more
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Rare Metals, EarlyView.ABSTRACT The development of sodium‐ion batteries (SIBs) is limited by slow charge transfer kinetics and large material volume changes caused by the large radius of Na+. Leveraging the excellent physicochemical properties and unique heterostructures of metal selenides, ultrafine hetero‐CuFeSe2‐CoSe2 nanoparticles are in situ wrapped by ...
Ying Zhu +5 more
wiley +1 more source
500 kV耦合负压换流型混合式直流断路器原理与研制 [PDF]
全球能源互联网, 2018 多端柔性直流系统在分布式能源和直流负荷接入、网络柔性互联、电能质量等方面具有显著优势，成为未来电网的重要发展趋势。为了保证多端柔性直流系统安全稳定可靠运行，需要能够在数毫秒内开断故障电流的直流断路器。本文面向张北±500 kV柔性直流电网示范工程的应用需求，开展了500 kV直流断路器原理研究与样机研制。首先，提出500 kV耦合负压换流型混合式直流断路器系统方案，给出其拓扑结构、工作原理和控制逻辑；进而，设计基于电磁斥力操动机构和电磁缓冲机构的快速机械开关 ...
张翔宇 +7 more
doaj +1 more source
Overview of ionospheric currents inversion by using low Earth orbit satellite magnetic observations [PDF]
With the development of satellite technology, low-orbit satellites equipped with high-resolution magnetometers have become an important tool for measuring the Earth's magnetic field, which provides continuous observations around the world regardless of ...
bohao Qian +8 more
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Rare Metals, EarlyView.ABSTRACT The development of highly efficient and stable nonprecious metal electrocatalysts for the acidic oxygen evolution reaction (OER) is crucial to advance proton exchange membrane (PEM) water electrolysis. In this work, a dual synergistic strategy was proposed by constructing a Ce‐modified MnO2/MnO heterostructure.
Chuanbin Li +7 more
wiley +1 more source
±500 kV柔直电网与新能源和常规发电机组的协调控制研究 [PDF]
全球能源互联网, 2018 张北±500 kV四端柔直电网工程的送端张北站和康保站作为新能源外送的汇集站，分别连接大规模风电场群，受端北京站和丰宁站分别作为新能源消纳中心和柔直电网的功率平衡节点与华北地区交流电网相连接，丰宁站建有抽蓄机组为系统提供紧急功率支撑。整个工程结构复杂，风电场群出力间歇性、随机性大，柔直系统直流电压对多端有功功率的吞吐平衡量敏感性强，受端负荷中心对电能质量要求高，这为柔直换流器、新能源风电机组和抽蓄机组的控制提出了严峻挑战。针对三者的协调控制展开研究，为柔直送端换流器设计了带频率附加控制的V-f控制 ...
王炳辉 +6 more
doaj +1 more source
Study on PMSM Servo System Algorithms and System Design [PDF]
, 2008 永磁同步电机现在已经成为伺服驱动的发展方向。研究高性能，宽调速范围的永磁同步电机伺服系统，必须研究先进的控制策略和控制手段，使系统具有较强的适应性和抗干扰能力。本文的主要工作就是围绕着高性能，宽调速范围永磁同步电机伺服系统的研究而展开。 本文对永磁同步电机的矢量控制原理和技术进行了分析和研究，指出矢量控制技术可以实现电机交轴和直轴之间的解耦，具有转矩控制的线性特性。能够比较平稳的输出转矩，且调速范围宽。结合伺服系统设计要求，确定系统的控制方案为矢量控制。 详细分析了伺服系统各部分的构成和数学模型 ...
洪涛
core
Rare Metals, EarlyView.ABSTRACT The development of efficient and stable bifunctional catalysts remains a key challenge for green hydrogen production via electrochemical water splitting. In this study, a bimetallic Mo/Fe‐doped CoP2 nanoleaf array anchored on carbon cloth (Mo, Fe‐CoP2@CC) was synthesized from zeolitic imidazolate framework‐L (ZIF‐L) via an ion‐exchange and low‐
Xiangqun Zeng +6 more
wiley +1 more source
基于ADPSS的锦苏特高压直流接入的江苏电网机电—电磁混合建模与仿真
Gaoya dianqi, 2013 为了精确地分析锦苏特高压直流接入后江苏电网,特别是直流换流站附近苏南电网的运行情况,在2013年江苏电网预计夏高负荷的基础上,基于电力系统全数字实时仿真平台（ADPSS）搭建了锦苏特高压直流系统的电磁暂态模型和江苏电网其余部分的机电模型。利用搭建的机电—电磁混合模型进行了特高压直流接入的江苏电网稳态仿真验证。在双极闭锁情况下对比了采用纯机电模型和机电—电磁混合模型的暂态仿真结果。仿真结果表明:机电—电磁混合模型能够有效地反映锦苏特高压直流输电系统的电磁暂态特性,适合于研究直流系统中十分复杂快速的暂态过程。
卫鹏, 汪成根, 周前
doaj
Rare Metals, EarlyView.ABSTRACT Expanding near‐infrared (NIR) spectral response and utilizing ultraviolet (UV) photons are effective strategies for enhancing the power conversion efficiency (PCE) of lead halide perovskite solar cells (PSCs). However, the range of NIR spectral response extension and the utilization of UV light for devices are not enough, and the loss of ...
Li He +9 more
wiley +1 more source