Results 21 to 30 of about 13,073 (198)

基于KEMA电弧模型的SF6断路器直流分量开断能力研究

open access: yesGaoya dianqi, 2020
电力系统短路电流中直流分量的衰减时间常数超过现有断路器的标准时间常数将导致断路器实际开断能力下降,因此亟需研究直流分量对高压断路器的影响以准确评估其开断能力,防止开断失败造成重大损失。文中提出基于KEMA电弧模型研究SF6断路器直流分量开断能力的方法。首先,将KEMA模型引入直流分量开断仿真中,给出额定开断能力对应的临界电弧参数获取方法,然后使用临界参数仿真实际含更高直流分量的短路电流,最后用该方法验证宁夏电网断路器的实际开断能力。研究结果表明,当断路器的额定开断能力包含20%的直流分量时 ...
丁培   +6 more
doaj  

Research on Methods of Modeling and Fault Diagnosis for Micro Direct-Current Motors [PDF]

open access: yes, 2015
直流微电机以体积小、重量轻、便于控制等优点被广泛应用于生产消费领域,在微型精密仪器中尤为重要。为了保证产品出厂品质,生产过程必须对直流微电机进行100%检测。目前检测主要依靠人工的经验来判断电机的好坏,其工作量大,生产效率低,漏检现象严重,导致电机出厂质量不稳定。因此有必要寻找一种简便和可靠的直流微电机在生产线上的故障检测技术。该技术即可以对出厂前的直流微电机进行自动在线检测,以保证直流微电机的出厂合格率;又可以推广应用于其他永磁直流电机的故障检测与诊断。 通过分析空载下直流电机的动态数学模型 ...
谢志平
core  

Tunable Redox‐Active Anhydride‐Based Linear Polymer as Organic Cathodes for Chemically Self‐Charging Aqueous Zinc–Ion Batteries

open access: yesRare Metals, Volume 45, Issue 3, March 2026.
ABSTRACT Chemically self‐charging aqueous zinc‐ion batteries (AZIBs) have emerged as promising candidates for energy storage technologies owing to their environmental autonomy and structural simplicity. Nonetheless, the self‐charging performance is significantly compromised by the limited potential difference between cathodes and oxygen, as well as the
Yan Wang   +5 more
wiley   +1 more source

Application of Magnetic Coupling Resonance Wireless Power Transfer in Power System [PDF]

open access: yes, 2022
Wireless power transfer (WPT) can transmit electric wirelessly. It performs better under some paticular circumstances compared with the traditonal transmission mode.
HE Hao   +4 more
core   +1 more source

Surface Sulfate Modification Promoted Excitons Extraction of BiOBr Nanosheets for Efficient 1O2 Photosynthesis and Chlorophenols Dechlorination

open access: yesRare Metals, Volume 45, Issue 2, February 2026.
ABSTRACT Photocatalytic molecular oxygen (O2) activation provides a sustainable approach to produce singlet oxygen (1O2) for organic contaminants detoxification. However, the charge carriers‐involved pathway usually suffers from unsatisfactory 1O2 production efficiency owing to energy loss caused by photogenerated hole‐mediated superoxide species (•O2−
Yan‐Biao Shi   +8 more
wiley   +1 more source

±500 kV高压直流XLPE电缆温度分布及其影响因素研究

open access: yesGaoya dianqi, 2023
温度分布是直流电缆运维检修的重要参数之一。由于高压直流输电起步较晚,高压直流电缆的研究不如交流电缆丰富、深入,因此对其温度分布影响因素的研究具有重要意义。通过Comsol有限元软件建立二维对称模型,计算±500 kV高压直流XLPE电缆稳态运行时的温度分布,求出适合电缆长期运行的载流量,并从载流量和环境温度两方面研究温度分布变化。仿真结果表明:载流量对温度分布变化具有较大的影响,当环境温度高于15℃时,导体温度约束载流量大小,环境温度低于15℃时,绝缘层最大允许温差约束载流量大小 ...
吴晶晶, 陈丽安, 严有祥, 赵鹏
doaj  

Study on properties of armature current for micro DC motors and multiple features of fault diagnosis [PDF]

open access: yes, 2015
针对直流微电机生产线上故障检测环节难以自动化的问题,提出一种基于故障多特征量的直流微电机故障诊断模型。通过分析空载和稳态下直流微电机的动态数学模型,推导出电枢电流的时域解析式,确定基于电枢电流的频域故障多特征量。以数台直流微电机为实验样本,分析其电枢电流时频域特征,对典型故障直流微电机运用定义的故障多特征量进行故障分析。实验结果表明不同故障电机的多特征量变化率明显不同,该故障多特征量可以被用来诊断直流微电机。A fault diagnostic model for the micro direct ...
伍卫, 洪剑锋, 谢志平
core  

Crystallization Engineering of GaAs/Sb2S3 Core‐Shell Nanowires for Gain Manipulation of Photodetectors

open access: yesRare Metals, Volume 45, Issue 2, February 2026.
ABSTRACT Photodetectors, based on GaAs nanowires (NWs), hold significant promise in the fields of high integration micro‐ and nano‐optoelectronics applications because of their outstanding electronic and optical properties. To date, significant efforts have been directed toward enhancing the performance of photodetectors, aiming for high detectivity ...
Yu Hao   +11 more
wiley   +1 more source

Objective assessment of communication speech interference effect based on feature fusion [PDF]

open access: yes, 2023
In view of the objective assessment problem of the effect of communication speech interference, methods based on multi-measurements and multimodal fusion were proposed.First, the interfered speech was preprocessed by the endpoint detection algorithm and ...
Huaitao XU   +4 more
core   +1 more source

Gravity‐Driven Inclination Sensor Based on Liquid Metal Interface Migration in Anisotropic Microchannels for Information Transmission and Continuous Surface Topography Scanning

open access: yesRare Metals, Volume 45, Issue 2, February 2026.
ABSTRACT With the continuous advancement of materials science and technology, the rare metal gallium has increasingly emerged as a promising alternative to the toxic metal mercury. Although existing research has predominantly focused on the high electrical conductivity and excellent deformability of liquid metal (LM), its intrinsic fluidic property ...
Feifan Guo   +6 more
wiley   +1 more source

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