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Organic X-Ray Image Sensors Using a Medium Bandgap Polymer Donor with Low Dark Current
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作者 Jong-Woon Ha Seung Hun Eom +11 位作者 Bo Kyung Cha Seyeong Song Hyeong Ju Eun Jong H.Kim Jong Mok Park BongSoo Kim Byoungwook Park Seo-Jin Ko Sung Cheol Yoon Changjin Lee In Hwan Jung Do-Hoon Hwang 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2024年第6期230-237,共8页
The development of portable X-ray detectors is necessary for diagnosing fractures in unconscious patients in emergency situations.However,this is quite challenging because of the heavy weight of the scintillator and s... The development of portable X-ray detectors is necessary for diagnosing fractures in unconscious patients in emergency situations.However,this is quite challenging because of the heavy weight of the scintillator and silicon photodetectors.The weight and thickness of X-ray detectors can be reduced by replacing the silicon layer with an organic photodetectors.This study presents a novel bithienopyrroledione-based polymer donor that exhibits excellent photodetection properties even in a thick photoactive layer(~700 nm),owing to the symmetric backbone and highly soluble molecular structure of bithienopyrroledione.The ability of bithienopyrroledione-based polymer donor to strongly suppress the dark current density(Jd~10−10 A cm^(−2))at a negative bias(−2.0 V)while maintaining high responsivity(R=0.29 A W−1)even at a thickness of 700 nm results in a maximum shot-noise-limited specific detectivity of D_(sh)^(*)=2.18×10^(13)Jones in the organic photodetectors.Printed organic photodetectors are developed by slot-die coating for use in X-ray detectors,which exhibit D_(sh)^(*)=2.73×10^(12)Jones with clear rising(0.26 s)and falling(0.29 s)response times upon X-ray irradiation.Detection reliability is also proven by linear response of the X-ray detector,and the X-ray detection limit is 3 mA. 展开更多
关键词 low dark current low detection limit organic photodetector printable X-RAY
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Application of fractal theory in detecting low current faults of power distribution system in coal mines 被引量:5
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作者 LIU Jian-hua LIANG Rui WANG Chong-lin FAN Di-peng 《Mining Science and Technology》 EI CAS 2009年第3期321-325,共5页
Single-phase low current grounding faults areoften seen in power distribution system of coal mines.These faults are difficult to reliably identify.We propose a new method of single-phase ground fault protection based ... Single-phase low current grounding faults areoften seen in power distribution system of coal mines.These faults are difficult to reliably identify.We propose a new method of single-phase ground fault protection based upon a discernible matrix of the fractal dimension associated with line currents.The method builds on existing selective protection methods.Faulted feeders are distinguished using differences in the zero-sequence transient current fractal dimension.The current signals were first processed through a fast Fourier transform and then the characteristics of a faulted line were identified using a discernible matrix.The method of calculation is illustrated.The results show that the method involves simple calculations, is easy to do and is highly accurate.It is, therefore, suitable for distribution networks having different neutral grounding modes. 展开更多
关键词 low current faults zero sequence transient current fractal dimension discernible matrix selective protection
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An NMOS output-capacitorless low-dropout regulator with dynamic-strength event-driven charge pump 被引量:1
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作者 Yiling Xie Baochuang Wang +1 位作者 Dihu Chen Jianping Guo 《Journal of Semiconductors》 EI CAS CSCD 2024年第6期23-34,共12页
In this paper,an NMOS output-capacitorless low-dropout regulator(OCL-LDO)featuring dual-loop regulation has been proposed,achieving fast transient response with low power consumption.An event-driven charge pump(CP)loo... In this paper,an NMOS output-capacitorless low-dropout regulator(OCL-LDO)featuring dual-loop regulation has been proposed,achieving fast transient response with low power consumption.An event-driven charge pump(CP)loop with the dynamic strength control(DSC),is proposed in this paper,which overcomes trade-offs inherent in conventional structures.The presented design addresses and resolves the large signal stability issue,which has been previously overlooked in the event-driven charge pump structure.This breakthrough allows for the full exploitation of the charge-pump structure's poten-tial,particularly in enhancing transient recovery.Moreover,a dynamic error amplifier is utilized to attain precise regulation of the steady-state output voltage,leading to favorable static characteristics.A prototype chip has been fabricated in 65 nm CMOS technology.The measurement results show that the proposed OCL-LDO achieves a 410 nA low quiescent current(IQ)and can recover within 30 ns under 200 mA/10 ns loading change. 展开更多
关键词 output-capacitorless low-dropout regulator fast transient low quiescent current event-driven charge pump
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Numerical Simulation of Low Current Vacuum Arc Supersonic Flow 被引量:2
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作者 王立军 贾申利 +2 位作者 史宗谦 张玲 荣命哲 《Plasma Science and Technology》 SCIE EI CAS CSCD 2007年第6期661-665,共5页
Based on a two-dimensional axisymmetric magneto-hydrodynamic (MHD) model, low current vacuum arc (LCVA) characteristics are studied. The influence of cathode process under different axial magnetic fields and diffe... Based on a two-dimensional axisymmetric magneto-hydrodynamic (MHD) model, low current vacuum arc (LCVA) characteristics are studied. The influence of cathode process under different axial magnetic fields and different anode radii on LCVA characteristics is also simulated. The results show that the influence of both cathode process and anode radii on LCVA is significant. The sign of anode sheath potentials can change from negative to positive with the decrease of anode radii. The simulation results are in part verified by experimental results. Especially, as the effect of ion kinetic energy is considered, ion temperature is improved significantly; which is in agreement with experimental results. 展开更多
关键词 low current vacuum arc MODEL SIMULATION
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Single-mode low threshold current multi-hole vertical-cavity surface-emitting lasers 被引量:1
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作者 赵振波 徐晨 +3 位作者 解意洋 周康 刘发 沈光地 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第3期232-235,共4页
A multi-hole vertical-cavity surface-emitting laser (VCSEL) operating in stable single mode with a low threshold current was produced by introducing multi-leaf scallop holes on the top distributed Bragg-refleetor of... A multi-hole vertical-cavity surface-emitting laser (VCSEL) operating in stable single mode with a low threshold current was produced by introducing multi-leaf scallop holes on the top distributed Bragg-refleetor of an oxidation- confined 850 nm VCSEL. The single-mode output power of 2.6 mW, threshold current of 0.6 mA, full width of half maximum lasing spectrum of less than 0.1 nm, side mode suppression ratio of 28.4 dB, and far-field divergence angle of about 10% are obtained. The effects of different hole depths on the optical characteristics are simulated and analysed, including far-field divergence, spectrum and lateral cavity mode. The single-mode performance of this multi-hole device is attributed to the large radiation loss from the inter hole spacing and the scattering loss at the bottom of the holes, particularly for higher order modes. 展开更多
关键词 single mode low threshold current multi-hole vertical-cavity surlace-emitting laser
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Influence of Jet Angle and Ion Density of Cathode Side on Low Current Vacuum Arc Characteristics
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作者 王立军 贾申利 史宗谦 《Plasma Science and Technology》 SCIE EI CAS CSCD 2008年第2期193-197,共5页
In this study, the influence of the initial jet angles (IJAs) and ion number densities (INDs) at the cathode side on the low current vacuum arc (LCVA) characteristics is simulated and analysed. The results show ... In this study, the influence of the initial jet angles (IJAs) and ion number densities (INDs) at the cathode side on the low current vacuum arc (LCVA) characteristics is simulated and analysed. The results show that the ion temperature, electron temperature, ion number density, axial current density and plasma pressure all decrease with the increase of the cathode IJAs. It is also shown that LCVA can cause a current constriction for lower cathode IND, and the anode sheath potential is more nonuniform, which is mainly related to the nonuniform distribution of the axial current density at the anode side. 展开更多
关键词 low current vacuum arc initial jet angles ion number density simulation
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Development of Surface Grating Distributed Feedback Quantum Cascade Laser for High Output Power and Low Threshold Current Density
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作者 刘颖慧 张锦川 +3 位作者 江建民 孙素娟 李沛旭 刘峰奇 《Chinese Physics Letters》 SCIE CAS CSCD 2015年第2期60-62,共3页
We report on the room-temperature cascade laser (QCL) at λ -4.7μm. cw operation of a surface grating Both grating design and material distributed feedback (DFB) quantum optimization are used to decrease the thre... We report on the room-temperature cascade laser (QCL) at λ -4.7μm. cw operation of a surface grating Both grating design and material distributed feedback (DFB) quantum optimization are used to decrease the threshold current density and to increase the output power. For a high-reflectivity-coated 13-μm-wide and 4- mm-long laser, high wall-plug efficiency of 6% is obtained at 20℃ from a single facet producing over I W of ew output power. The threshold current density of DFB QCL is as low as 1.13kA/cm^2 at 10℃ and 1.34kA/cm2 at 30℃ in cw mode. Stable single-mode emission with a side-mode suppression ratio of about 30 dB is observed in tile working temperature range of 20-50℃. 展开更多
关键词 DFB QCL Development of Surface Grating Distributed Feedback Quantum Cascade Laser for High Output Power and low Threshold current Density
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Temperature-Dependent Drain Current Characteristics and Low Frequency Noises in Indium Zinc Oxide Thin Fihn Transistors
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作者 刘远 吴为敬 +3 位作者 强蕾 王磊 恩云飞 李斌 《Chinese Physics Letters》 SCIE CAS CSCD 2015年第8期208-211,共4页
The I-V characteristics and low frequency noises for indium zinc oxide thin film transistor are measured between 250 K and 430 K. The experimental results show that drain currents are thermally activated following the... The I-V characteristics and low frequency noises for indium zinc oxide thin film transistor are measured between 250 K and 430 K. The experimental results show that drain currents are thermally activated following the Meyer Neldel rule, which can be explained by the multiple-trapping process. Moreover, the field effect electron mobility firstly increases, and then decreases with the increase of temperature, while the threshold voltage decreases with increasing the temperature. The activation energy and the density of localized gap states are extracted. A noticeable increase in the density of localized states is observed at the higher temperatures. 展开更多
关键词 TFT Temperature-Dependent Drain current Characteristics and low Frequency Noises in Indium Zinc Oxide Thin Fihn Transistors
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LOW TEMPERATURE ALUMINUM FLOATING ELECTROLYSIS IN HEAVY ELECTROLYTE Na_3AlF_6-AlF_3-BaC1_2-NaCl BATH SYSTEM 被引量:4
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作者 H.M. Lu and K.M. Fang Metallurgy School, University of Science and Technology Beijing, Beijing 100083, China Z.X. Qiu Department of Nonferrous Metallurgy, Northeastern University, Shenyang 110006, China 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2000年第4期949-954,共6页
Multiple regression equations of liquidus temperature, electrical conductivity and bath density of the Na_3AlF_6-AlF_3-BaC1_2-NaCl system were obtained from experiments by using orthogonal regression method. The exper... Multiple regression equations of liquidus temperature, electrical conductivity and bath density of the Na_3AlF_6-AlF_3-BaC1_2-NaCl system were obtained from experiments by using orthogonal regression method. The experiments were carried out in 100A cell with low melting point electrolyte, the influences of cathodic current density, electrolytic temperature, density differences of bath and liquid aluminum on current efficiency (CE) were studied; when the electrolyte cryolite ratio was 2.5, w(BaC1_2) and w(NaCl) were 48% and 10%, respectively, CE reached 90% and specific energy consumption was 10.97k Wb/kg/kg. Because of the fact that aluminum metal obtained floated on the surface of molten electrolyte, this electrolysis method was then defined as low temperature aluminum floating electrolysis. The results showed that the new low temperature aluminum electrolysis process in the Na_3AlF_6-AlF_3-BaC1_2-NaCl bath system was practical and promising. 展开更多
关键词 low temperature aluminum floating electrolysis Na_3AlF_6- AlF_3BaC1_2-NaCl bath system current efficiency physico-chemical property
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Modeling of Residential Photovoltaic (PV) System Connected to Low Voltage (LV) Network: Application to Public Distribution Network of Burkina Faso
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作者 Abdoulaye Zongo Daouda Konane Frédéric Ouattara 《Journal of Applied Mathematics and Physics》 2022年第9期2698-2707,共10页
Residential photovoltaic (PV) systems connected to the grid are used for self-consumption. Any surplus production is fed into the grid and contributes to improving the voltage. Several techniques are developed to mode... Residential photovoltaic (PV) systems connected to the grid are used for self-consumption. Any surplus production is fed into the grid and contributes to improving the voltage. Several techniques are developed to model their connection. However, studies on methods of injecting energy production into the Low Voltage (LV) network are nowadays a problem. This paper proposes a mathematical model to determine the current to be injected and calculate each node’s voltage. The current equation is a recurrence relation with an initial condition. This initial condition is for the case of a single PV system connected to the LV grid. The equation can also be written in matrix form. Similarly, the voltage solution is a recurrence relation. It also has an initial condition for the first node. Both mathematical formulae with the proposed initial conditions are consistent and can be used for the determination of the current and voltage of the different nodes in the grid. 展开更多
关键词 Residential PV system low Voltage Grid NODE Mathematical Model Electric current
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Current Source Converter Based Wind Energy Conversion Systems
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作者 Samir Kouro Jing-ya DAI Bin WU 《电力电子技术》 CSCD 北大核心 2011年第8期3-10,共8页
The increase in the installed capacity of wind energy conversion systems(WECS) has triggered the devel-opment of more demanding grid codes and additional requirements on performance.In order to meet these require-ment... The increase in the installed capacity of wind energy conversion systems(WECS) has triggered the devel-opment of more demanding grid codes and additional requirements on performance.In order to meet these require-ments the industry trend has shifted to full-scale power converter interfaces in modern multi-megawatt WECS.As con-sequence,a wide variety of new power converter topologies and WECS configurations have been introduced in recent years.Among them,current source converter(CSC) based configurations have attracted attention due to a series of advantages like:simple structure,grid friendly waveforms,controllable power factor,and reliable grid short-circuit pro-tection.This paper presents the latest developments in CSC interfaces for WECS and related technologies such as modulation methods,control schemes and grid code compatibility. 展开更多
关键词 摘要 编辑部 编辑工作 作者
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柔性低频输电系统的主变稳态负序差动保护 被引量:1
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作者 顾乔根 张晓宇 +2 位作者 吕航 莫品豪 孙仲民 《电力系统保护与控制》 EI CSCD 北大核心 2024年第5期168-177,共10页
为了解决常规纵差保护难以适用于低频系统的问题,通过分析低频系统的序分量抑制策略,并根据低频系统故障进入稳态后单侧有负序注入的特征,提出一种基于稳态负序分量的主变差动保护方法。为防止该差动保护在区外故障时因电流互感器饱和... 为了解决常规纵差保护难以适用于低频系统的问题,通过分析低频系统的序分量抑制策略,并根据低频系统故障进入稳态后单侧有负序注入的特征,提出一种基于稳态负序分量的主变差动保护方法。为防止该差动保护在区外故障时因电流互感器饱和出现误动,通过对比分析三类制动电流计算方式的制动性能,得到了差动保护的制动方程和制动系数。为解决励磁涌流、电流互感器断线可能导致误动的问题,提出了相电压突变量的差动保护开放条件。仿真分析表明,该方法能够灵敏反映区内金属性故障及轻微故障,在区外故障伴随电流互感器饱和时有可靠的制动裕度。 展开更多
关键词 低频输电系统 负序差动 励磁涌流 互感器饱和 零启升压
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高速列车弓网受流系统放电实验平台设计
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作者 曾晗 符思雨 +3 位作者 朱彦锦 韦宝泉 李泽文 邓芳明 《实验技术与管理》 CAS 北大核心 2024年第1期171-177,共7页
为掌握外环境下高速列车的运行特点,开展弓网电弧变化特性研究,该文设计并研制了高速列车弓网受流系统放电实验平台,其风洞系统由风洞结构、风扇转子系统、风洞控制系统、弓网电弧发生系统、观测系统组成。测试结果表明:低速直流风洞风... 为掌握外环境下高速列车的运行特点,开展弓网电弧变化特性研究,该文设计并研制了高速列车弓网受流系统放电实验平台,其风洞系统由风洞结构、风扇转子系统、风洞控制系统、弓网电弧发生系统、观测系统组成。测试结果表明:低速直流风洞风速可达50 m/s,湍流度低于1%,速度不均匀性小于1%,流场稳定性不超过1%,气流偏角不超过0.5°,满足《低速风洞和高速风洞流场品质要求》(GJB 1179A—2012)中所规定的参数指标。该系统为探究强气流场环境下弓网电弧物理特性的变化规律提供了良好的实验环境,可为高速运行环境下列车弓网电弧研究提供参考数据。 展开更多
关键词 低速直流风洞 风洞系统 强气流场环境 弓网电弧
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基于线路容流暂态信号能量流向特征的小电流单相接地故障区段定位算法 被引量:1
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作者 谭卫斌 吴浩波 +2 位作者 张志华 隆博 张敏 《现代电子技术》 北大核心 2024年第2期121-126,共6页
针对配电网小电流系统单相接地故障定位难的问题,提出一种基于线路容流暂态信号能量流向特征的小电流单相接地故障定位算法。该算法能够在故障发生时准确识别故障线路并定位故障区间,同时对故障前后波形的离散采样数据进行软件滤波,得... 针对配电网小电流系统单相接地故障定位难的问题,提出一种基于线路容流暂态信号能量流向特征的小电流单相接地故障定位算法。该算法能够在故障发生时准确识别故障线路并定位故障区间,同时对故障前后波形的离散采样数据进行软件滤波,得到线路的容流暂态信号分量,利用其能量流向特征对单相接地故障进行识别和区段定位。实验结果表明,所提算法能够准确区分出故障与非故障线路区段,具有自举性,可方便应用于就地型馈线自动化开关节点,具有较好的实用性。 展开更多
关键词 配电网 小电流系统 单相接地故障 容流暂态信号 故障定位 傅里叶变换
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基于低频暂态零序电流畸变率的灵活接地系统高阻接地保护
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作者 李晓波 张世乐 彭超红 《电力系统自动化》 EI CSCD 北大核心 2024年第13期171-183,共13页
灵活接地系统中,基于稳态故障特征构成的单相接地保护普遍存在耐过渡电阻能力低的问题,并联小电阻投入后该问题进一步突出。文中研究了并联小电阻投入后故障线路与非故障线路低频暂态零序电流中暂态直流分量比值关系,发现暂态直流分量... 灵活接地系统中,基于稳态故障特征构成的单相接地保护普遍存在耐过渡电阻能力低的问题,并联小电阻投入后该问题进一步突出。文中研究了并联小电阻投入后故障线路与非故障线路低频暂态零序电流中暂态直流分量比值关系,发现暂态直流分量比值仅与对地电容有关。分析了故障线路与非故障线路低频暂态零序电流畸变率之间比值关系,进一步提出了一种基于低频暂态零序电流畸变率的灵活接地系统单相高阻接地故障选线方法。通过比较特定时间窗口内各馈线低频暂态零序电流畸变率的大小实现故障选线,并可准确区分母线故障与出线故障。该方法能够避免零序电压互感器断线与零序电流互感器极性反接的影响,且受故障距离影响小。同时,该方法采用暂态故障特征构成选线判据,有利于克服并联小电阻投入后稳态故障分量微弱的问题,对互感器精度要求不高。最后,通过实时数字仿真和实验平台分别验证了所述方法的准确性和有效性。 展开更多
关键词 配电网 灵活接地系统 低频暂态 零序电流 零序电压 高阻接地故障
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小电流接地配电网馈线单相接地故障零序阻抗特性分析
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作者 李纳纳 王宾 《电测与仪表》 北大核心 2024年第6期58-64,共7页
文章以暂态零序特征为着眼点,从频域角度对小电流接地系统发生单相接地故障后的特性进行详细探讨。从线路入端零序阻抗这一随频率变化的特征量入手,深入挖掘了配电网系统中各馈线零序阻抗的阻抗特性,详细探讨了零序阻抗的幅值、相角随... 文章以暂态零序特征为着眼点,从频域角度对小电流接地系统发生单相接地故障后的特性进行详细探讨。从线路入端零序阻抗这一随频率变化的特征量入手,深入挖掘了配电网系统中各馈线零序阻抗的阻抗特性,详细探讨了零序阻抗的幅值、相角随频率的变化规律,并针对不同的中性点接地方式以及线路是否健全加以分析,为更好地利用零序暂态信号,提高故障检测正确率夯实了基础。最后通过PSCAD搭建仿真模型验证了该特性。 展开更多
关键词 小电流接地 暂态 单相接地故障 零序阻抗 仿真
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北太平洋低纬度西边界流系湍流混合的微观结构测量和参数化方法评估
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作者 孙斌 周慧 +4 位作者 汪嘉宁 杨文龙 刘恒昌 于晓彤 董焕河 《海洋与湖沼》 CAS CSCD 北大核心 2024年第4期817-829,共13页
湍流混合在调控海洋垂向物质、能量交换以及气候变化中都起着重要作用,尤其是在北太平洋低纬度西边界流系,湍流混合通过调节温跃层及海气相互作用,在西太平洋暖池结构及演化和厄尔尼诺与南方涛动的发生、发展中都起着关键作用。然而,由... 湍流混合在调控海洋垂向物质、能量交换以及气候变化中都起着重要作用,尤其是在北太平洋低纬度西边界流系,湍流混合通过调节温跃层及海气相互作用,在西太平洋暖池结构及演化和厄尔尼诺与南方涛动的发生、发展中都起着关键作用。然而,由于湍流观测的高风险性和高费船时特征,直接的湍流观测资料非常稀缺,因此,对该海域的湍流混合认知大多数来自细尺度参数化估计。鉴于湍流的高时变特征及该海域海洋环流结构的复杂性及西边界流区动力环境的特殊性,验证不同细尺度参数化方法对该海域湍流估算的适用性对于我们准确了解该海域的垂向混合特征、提升其在数值模拟的精度具有重要作用。本研究利用2020年9月在北太平洋低纬度西边界流系沿130°E,10°~18°N进行的直接的微结构观测剖面仪和同期获取的细尺度温盐流测量,研究该海域湍流混合的特征及两种常用的参数化方法--GHP(Gregg-Henyey-Polzin)参数化方法、MG(MacKinnon-Gregg)参数化方法在该海域的适用性。观测结果表明,该海域上200 m湍流混合总体较强,直接观测得到的平均湍动能耗散率约为10^(-8)W/kg。在温跃层中,某些站点观测的湍动能耗散率可达10^(-7)W/kg,特别是在14°N附近,24.5σθ与25.5σθ之间发现一块强湍动能耗散区,初步分析表明其机制与全日内潮的参数化次谐波不稳定有关。参数化评估结果显示,MG方法与观测值相差0.5个数量级的比例为95%,而基于应变的GHP方法和基于剪切的GHP方法与观测值相差0.5个数量级的比例分别为55%和58%,表明MG方法能较好地估算低纬度西边界流系的湍流混合特征并在水平分布和垂直分布表现出一致的分布特征。该评价结果可为研究人员选择细尺度参数化来探讨北太平洋低纬度西边界流系湍流混合的强度和空间分布提供有益参考。 展开更多
关键词 北太平洋低纬度西边界流系 微结构观测 GHP参数化方法 MG参数化方法
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基于BP神经网络算法的小电流接地选线研究
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作者 孙冰 李长星 《电工技术》 2024年第8期139-143,共5页
现有的传统方法对小电流接地系统单相接地故障的选线正确率较低,为了解决这一问题,首先对小电流接地系统发生单相接地故障时的零序信号进行分析,然后选取3种传统选线方法,分析其选线原理并进行选线仿真,最后建立基于BP神经网络的综合选... 现有的传统方法对小电流接地系统单相接地故障的选线正确率较低,为了解决这一问题,首先对小电流接地系统发生单相接地故障时的零序信号进行分析,然后选取3种传统选线方法,分析其选线原理并进行选线仿真,最后建立基于BP神经网络的综合选线算法,将3种传统方法进行融合,使其具有更强的针对性和适用性,从而提高选线的准确率。 展开更多
关键词 小电流接地系统 单相接地 BP神经网络
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Low Voltage Direct Current Supply and Utilization System:Definition,Key Technologies and Development 被引量:1
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作者 Zhao Ma Yahui Li +1 位作者 Yuanyuan Sun Kaiqi Sun 《CSEE Journal of Power and Energy Systems》 SCIE EI CSCD 2023年第1期331-350,共20页
With rapid increase of distributed solar power generation and direct current(DC)based loads such as data centers,electric vehicles(EVs),and DC household appliances,the development trend of the power system is changed ... With rapid increase of distributed solar power generation and direct current(DC)based loads such as data centers,electric vehicles(EVs),and DC household appliances,the development trend of the power system is changed from conventional alternate current(AC)to DC.Traditional AC power systems can scarcely meet the development demand of new DC trends,especially since both the generation side and load side are comprised of DC-based electronic power components.With this background,low voltage direct current supply and utilization system(LVDCSUS)has attracted more and more attention for its great advantages over an AC grid to overcome challenges in operation,reliability,and energy loss in renewable energy connection,DC load power utilization and a number of other aspects.However,the definition of the LVDCSUS is still not clear even though many demonstration projects have been put into planning and operation.In order to provide a clear description of LVDCSUS,first,the characteristics of LVDCSUS are illustrated in this paper to show the advance of the LVDCSUS.Second,the potential application scenarios of LVDCSUS are presented in this paper.Third,application of LVDCSUS technologies and some demonstration projects in China are introduced.Besides the development of the LVDCSUS,key technologies,including but not limited to planning and design,voltage levels,control strategies,and key equipment of LVDCSUS,are discussed in this paper.Finally,future application areas and the research orientations of LVDCSUS are analyzed. 展开更多
关键词 Distributed energy resource information communication technology Internet of Things low voltage direct current supply and utilization system renewable energy
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自触型低压混合式直流断路器系统设计与开断特性研究 被引量:1
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作者 张照资 高偲智 +3 位作者 汪倩 陈思磊 葛世伟 李兴文 《中国电机工程学报》 EI CSCD 北大核心 2024年第11期4544-4555,I0032,共13页
低压混合式直流断路器具有低功耗、高开断性能、选择性保护等优点,能更好地满足光伏和储能系统以及零碳建筑等应用需求。该文提出一种自触型低压混合式直流开关拓扑,首先通过对混合式断路器工作原理分析,建立基于电弧供能、驱动的机电... 低压混合式直流断路器具有低功耗、高开断性能、选择性保护等优点,能更好地满足光伏和储能系统以及零碳建筑等应用需求。该文提出一种自触型低压混合式直流开关拓扑,首先通过对混合式断路器工作原理分析,建立基于电弧供能、驱动的机电系统耦合设计方法,该方法利用电弧能量为电子电路供能,并将电弧电压作为换流支路导通的控制信号,从而实现短路故障下系统的自动触发,并提出核心功能模块设计的理论依据。在此基础上,研制低压混合式断路器样机并验证设计方案的有效性,并对比分析不同因素对开断特性的影响规律。试验表明,相较于传统机械开关,小电流开断时间缩短85.4%、电弧能量减少94.1%,提升了断路器电气寿命,同时实现1.1 kA短路电流开断,发现系统总体响应时间与燃弧初期电压上升速率成正相关,电弧电导、支路寄生电感增大均会延长换流时间,电弧重燃概率则主要受外部系统参数影响。结果可为低压直流混合式断路器的优化设计和性能提升提供一定参考。 展开更多
关键词 低压直流系统 混合式断路器 断路器寿命 小电流开断 短路开断
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