期刊文献+
共找到21篇文章
< 1 2 >
每页显示 20 50 100
A super junction SiGe low-loss fast switching power diode 被引量:1
1
作者 马丽 高勇 《Chinese Physics B》 SCIE EI CAS CSCD 2009年第1期303-308,共6页
This paper proposes a novel super junction (S J) SiGe switching power diode which has a columnar structure of alternating p- and n- doped pillar substituting conventional n- base region and has far thinner strained ... This paper proposes a novel super junction (S J) SiGe switching power diode which has a columnar structure of alternating p- and n- doped pillar substituting conventional n- base region and has far thinner strained SiGe p+ layer to overcome the drawbacks of existing Si switching power diode. The SJ SiGe diode can achieve low specific on-resistance, high breakdown voltages and fast switching speed. The results indicate that the forward voltage drop of SJ SiGe diode is much lower than that of conventional Si power diode when the operating current densities do not exceed 1000 A/cm^2, which is very good for getting lower operating loss. The forward voltage drop of the Si diode is 0.66V whereas that of the SJ SiGe diode is only 0.52V voltages are 203 V for the former and 235 V for the latter. at operating current density of 10A/cm^2. The breakdown Compared with the conventional Si power diode, the reverse recovery time of SJ SiGe diode with 20 per cent Ge content is shortened by above a half and the peak reverse current is reduced by over 15%. The SJ SiGe diode can remarkably improve the characteristics of power diode by combining the merits of both SJ structure and SiGe material. 展开更多
关键词 super junction SiGe diode fast switching LOW-LOSS
下载PDF
Study of the Fast-Closing Switch Used for Fault Current Limiters in Power System 被引量:1
2
作者 邹积岩 董恩源 陈金祥 《Journal of Shanghai University(English Edition)》 CAS 2002年第1期92-96,共5页
This paper presents a new type of fault current limiter (FCL) based on fast closing switch, which is composed of a capacitor bank and a reactor in series. The main control component is a fast closing switch connecte... This paper presents a new type of fault current limiter (FCL) based on fast closing switch, which is composed of a capacitor bank and a reactor in series. The main control component is a fast closing switch connected in parallel with the capacitors, which is driven by the electromagnetic repulsion force. It can response the order within 1 ms. When fault occurs, the switch closes and the capacitors are bypassed, and the fault current is limited by the reactor. Simulation analysis and experiment show that the electromagnetic repulsion force actuator can meet the demand of fast closing switch, it is feasible to develop the FCL with low cost and high reliability. 展开更多
关键词 fault current limiter (FCL) electromagnetic repulsion force fast closing switch simulation.
下载PDF
Global Synchronization of Directed Networks with Fast Switching Topologies
3
作者 LU Xin-Biao QIN Bu-Zhi LU Xin-Yu 《Communications in Theoretical Physics》 SCIE CAS CSCD 2009年第12期1019-1024,共6页
Global synchronization of a class of directed dynamical networks with switching topologies is investigated.It is found that if there is a directed spanning tree in the fixed time-average of network topology and the ti... Global synchronization of a class of directed dynamical networks with switching topologies is investigated.It is found that if there is a directed spanning tree in the fixed time-average of network topology and the time-averageis achieved sufficiently fast,then the network will reach global synchronization for sufficiently large coupling strength. 展开更多
关键词 global synchronization directed network fast switch
下载PDF
Vacuum Switching Technology for Future of Power Systems 被引量:1
4
作者 Xiaofei Yao Jianhua Wang +3 位作者 Shaogui Ai Zhiyuan Liu Yingsan Geng Zhiguo Hao 《Engineering》 SCIE EI CAS 2022年第6期164-177,共14页
Even though switching in vacuum is a technology with almost 100 years of history,its recent develop-ments are still changing the future of power transmission and distribution systems.First,current switch-ing in vacuum... Even though switching in vacuum is a technology with almost 100 years of history,its recent develop-ments are still changing the future of power transmission and distribution systems.First,current switch-ing in vacuum is an eco-friendly technology compared to switching in SF 6 gas,which is the strongest greenhouse gas according to the Kyoto Protocol.Vacuum,an eco-friendly natural medium,is promising for reducing the usage of SF 6 gas in current switching in transmission voltage.Second,switching in vacuum achieves faster current interruption than existing alternating current(AC)switching technolo-gies.A vacuum circuit breaker(VCB)that uses an electromagnetic repulsion actuator is able to achieve a theoretical limit of AC interruption,which can interrupt a short-circuit current in the first half-cycle of a fault current,compared to the more common three cycles for existing current switching technologies.This can thus greatly enhance the transient stability of power networks in the presence of short-circuit faults,especially for ultra-and extra-high-voltage power transmission lines.Third,based on fast vacuum switching technology,various brilliant applications emerge,which are benefiting the power systems.They include the applications in the fields of direct current(DC)circuit breakers(CBs),fault current lim-iting,power quality improvement,generator CBs,and so forth.Fast vacuum switching technology is promising for controlled switching technology in power systems because it has low variation in terms of opening and closing times.With this controlled switching,vacuum switching technology may change the“gene”of power systems,by which power switching transients will become smoother. 展开更多
关键词 Controlled switching Electromagnetic repulsion actuator fast vacuum circuit breaker fast vacuum switching technology Vacuum interrupter
下载PDF
Stability and stabilisation of Markovian jump systems under fast switching: an averaging approach
5
作者 Guoliang Wang Yande Zhang Yunshuai Ren 《Journal of Control and Decision》 EI 2023年第4期572-583,共12页
ABSTRACTThis paper addresses the problems of stability and stabilisation of Markovian jump systems(MJSs) with fast switching. First, a novel model by applying an averaging approach to the fastswitching is proposed. Th... ABSTRACTThis paper addresses the problems of stability and stabilisation of Markovian jump systems(MJSs) with fast switching. First, a novel model by applying an averaging approach to the fastswitching is proposed. Then, a new method for constructing an auxiliary system is given to makethe stability analysis. It is proved that the stability of the originally fast switching MJS couldbe guaranteed by an MJS with an average switching, if the fast switching achieves its averageapproximation sufficiently fast. Based on the proposed results, some extensions about generally stabilising controllers are considered, where the fault-tolerant situation is involved too.All the conditions are presented in terms of LMIs. Finally, two numerical examples are used todemonstrate the effectiveness and superiority of the method. 展开更多
关键词 Markovian jump systems fast switching averaging approach STABILITY stabilisation linear matrix inequalities(LMIs)
原文传递
快速响应磁控电抗器抑制特高压操作过电压研究 被引量:10
6
作者 邢海瀛 陈柏超 +2 位作者 张亚迪 田翠华 袁佳歆 《电力自动化设备》 EI CSCD 北大核心 2009年第1期15-18,共4页
针对高电压等级电网的过电压限制与无功补偿存在矛盾的问题,提出了一种大容量并具有快速响应能力的磁控电抗器的设计方案。磁控电抗器的本体采用单相双绕组结构,保证了运行可靠性;接入电网的三相电抗器组的工作绕组以星形联结,中性点接... 针对高电压等级电网的过电压限制与无功补偿存在矛盾的问题,提出了一种大容量并具有快速响应能力的磁控电抗器的设计方案。磁控电抗器的本体采用单相双绕组结构,保证了运行可靠性;接入电网的三相电抗器组的工作绕组以星形联结,中性点接小电抗,控制绕组为三角形联结以减小输出谐波;通过对低压控制回路直流电压的调节实现对电抗器输出容量的控制。提出2种励磁方式实现了磁控电抗器响应速度的大幅提高;也可采用控制绕组短接的方法实现电抗器容量的突增,以限制线路的操作过电压水平。应用一条1000 kV特高压线路模型,对采用常规并联高压电抗器和磁控高压电抗器时对三相对称合闸过电压的限制效果进行了计算分析,结果表明应用快速响应磁控电抗器可以对特高压线路操作过电压进行有效限制。 展开更多
关键词 磁控电抗器 特高压 操作过电压 过电压抑制 快速响应
下载PDF
GIS中快速暂态过电压的研究 被引量:5
7
作者 高有华 孙彤 +1 位作者 申力 梁秦 《沈阳工程学院学报(自然科学版)》 2008年第1期32-34,共3页
阐述了气体绝缘开关装置(GIS)中隔离开关操作所产生的特快速瞬变过程(VFT),分析了快速暂态过电压(VFTO)形成的机理、特性及其对GIS本身和相连的电力变压器可能带来的危害.讨论了变压器入口电容、母线残余电荷以及支撑绝缘子的参数变化... 阐述了气体绝缘开关装置(GIS)中隔离开关操作所产生的特快速瞬变过程(VFT),分析了快速暂态过电压(VFTO)形成的机理、特性及其对GIS本身和相连的电力变压器可能带来的危害.讨论了变压器入口电容、母线残余电荷以及支撑绝缘子的参数变化对快速暂态过电压幅值的影响,并给出了VFTO的变化规律.探究了VFTO下电力变压器的模型及不同变压器模型对GIS内部元件处VFTO数值的影响,指出了影响VFTO数值的关键因素是变压器的等值入口电容值. 展开更多
关键词 气体封闭组合电器(GIS) 快速暂态过电压 隔离开关
下载PDF
GIS中VFTO影响因素的分析 被引量:3
8
作者 孙彤 高有华 《沈阳师范大学学报(自然科学版)》 CAS 2008年第4期429-431,共3页
针对实际500kV GIS中隔离开关分合母线充电电流电路,确定了数值模拟快速暂态过电压(VFTO)的等值电路,对VFTO进行了数值模拟,并讨论了变压器入口电容、母线残余电荷等元件参数的变化对VFTO幅值的影响.
关键词 气体绝缘开关装置(GIS) 快速暂态过电压(VFTO) 数值模拟
下载PDF
高压厂用备用电源是否需要装设快切装置的分析 被引量:4
9
作者 龚大德 《电力勘测设计》 2006年第6期35-39,共5页
“火力发电厂设计技术规程”(DL5000-2000)(以下称为《大火规》)的适用范围是“汽轮发电机组容量为125MW^600MW级机组的凝汽式火力发电厂,600MW级及以上可参照使用。”“火力发电厂厂用电设计技术规定”(DL/T 5153-2002)(以下称为《厂... “火力发电厂设计技术规程”(DL5000-2000)(以下称为《大火规》)的适用范围是“汽轮发电机组容量为125MW^600MW级机组的凝汽式火力发电厂,600MW级及以上可参照使用。”“火力发电厂厂用电设计技术规定”(DL/T 5153-2002)(以下称为《厂用电技规》)的适用范围是“汽轮发电机组容量为125MW及以上新建或扩建的凝汽式发电厂。”两规程都不能提供明确的解决方案。或者说,两规程对600MW机组工程的设计,在厂用备用电源的设计方面,尚存在一些不足之处,使得在目前的1000MW机组的设计中,出现了一些难于处理的问题,需要在实践中解决。 展开更多
关键词 厂用电 备用电源 快切 装置
下载PDF
GIS中VFTO、VFTC统计特性试验和仿真方法研究 被引量:19
10
作者 段韶峰 赵琳 +3 位作者 李志兵 詹花茂 李成榕 姚林志 《电网技术》 EI CSCD 北大核心 2015年第12期3634-3640,共7页
针对现有的特快速瞬态过电压(very fast transient over-voltage,VFTO)仿真模型,未考虑实际开关触头间隙击穿电压曲线、击穿电压随机性、工频初始相位随机性等因素,不能准确反映开关动作全过程中VFTO、特快速瞬态电流(very fast transie... 针对现有的特快速瞬态过电压(very fast transient over-voltage,VFTO)仿真模型,未考虑实际开关触头间隙击穿电压曲线、击穿电压随机性、工频初始相位随机性等因素,不能准确反映开关动作全过程中VFTO、特快速瞬态电流(very fast transient current,VFTC)的统计特性的问题,首先,建立了252 kV特快速瞬态试验回路,进行了数百次隔离开关分/合闸操作试验,通过统计分析获得了隔离开关触头间隙击穿电压随开距的变化曲线;其次,结合双指数型高频电弧电阻模型,建立了试验平台的暂态仿真电路,并采用基于Matlab控制EMTP/ATP的方式和变步长技术,实现了隔离开关分/合闸全过程的高效准确仿真;最后,利用N-W回归算法获得了实测和仿真中VFTO、VFTC波形的统计特性。研究结果表明:2个统计特性吻合良好,验证了该仿真方法的有效性。 展开更多
关键词 隔离开关 特快速瞬态电压 特快速瞬态电流 变步长 多次重复击穿 随机性模拟 统计特性
下载PDF
Ferroelectric liquid crystals for fast switchable circular Dammann grating [Invited] 被引量:1
11
作者 Qi Guo Tian Liu +5 位作者 Xiaoqian Wang Zhigang Zheng Aleksey Kudreyko Huijie Zhao V.Chigrinov Hoi-Sing Kwok 《Chinese Optics Letters》 SCIE EI CAS CSCD 2020年第8期2-5,共4页
Diffractive optical elements attract a considerable amount of attention, mainly due to their potential applications in imaging coding, optical sensing, etc. Application of ferroelectric liquid crystals(FLCs) with phot... Diffractive optical elements attract a considerable amount of attention, mainly due to their potential applications in imaging coding, optical sensing, etc. Application of ferroelectric liquid crystals(FLCs) with photoalignment technology in diffractive optical elements results in a high efficiency and a fast response time. In this study we demonstrate a circular Dammann grating(CDG) with a diffraction efficiency of 84.5%. The achieved response time of 64 μs is approximately two orders of magnitude faster than the existing response time of nematic liquid crystal devices. By applying a low electric field(V = 6 V) to the FLC CDG, it is switched between the eight-order diffractive state and the transmissive diffraction-free state. 展开更多
关键词 ferroelectric liquid crystals PHOTO-ALIGNMENT fast switching diffractive optical elements
原文传递
主变压器倒送电前快切系统动态调试的新方法 被引量:1
12
作者 陈淑琴 张献辉 +1 位作者 刘宏 李兴照 《华电技术》 CAS 2011年第10期66-68,85,共3页
针对调度不建议进行主变压器倒送电试验的情况,设计了一种新的快切调试方法。该方法可实现机组启动前厂用电动态切换,提高机组正常投运后快切系统动态切换的准确性。
关键词 主变压器 快切系统 动态切换 动态调试 新方法
下载PDF
西塞山发电厂母线充电保护快速切换的改进 被引量:2
13
作者 杨挺 《湖北电力》 2004年第5期58-59,62,共3页
 介绍了对西塞山发电厂母线充电保护装置的改进,解决了充电保护的动作时间不能快速切换的问题,提高了保护装置的可靠性和使用寿命,减少了运行人员的操作程序。
关键词 充电保护 改进 快速切换
下载PDF
A snapback-free and high-speed SOI LIGBT with double trenches and embedded fully NPN structure
14
作者 Chenxia Wang Jie Wei +2 位作者 Diao Fan Yang Yang Xiaorong Luo 《Journal of Semiconductors》 EI CAS CSCD 2020年第10期50-55,共6页
A novel 600 V snapback-free high-speed silicon-on-insulator lateral insulated gate bipolar transistor is proposed and investigated by simulation.The proposed device features an embedded NPN structure at the anode side... A novel 600 V snapback-free high-speed silicon-on-insulator lateral insulated gate bipolar transistor is proposed and investigated by simulation.The proposed device features an embedded NPN structure at the anode side,and double trenches together with an N-type carrier storage(N-CS)layer at the cathode side,named DT-NPN LIGBT.The NPN structure not only acts as an electron barrier to eliminate the snapback effect in the on-state within a smaller cell pitch but also provides an extra electron extracting path during the turn-off stage to decrease the turnoff loss(E_(off)).The double cathode trenches and N-CS layer hinder the hole from being extracted by the cathode quickly.They then enhance carrier storing effect and lead to a reduced on-state voltage drop(V_(on)).The latch-up immunity is improved by the double cathode trenches.Hence,the DT-NPN LIGBT obtains a superior tradeoff between the V_(on)and E_(off).Additionally,the DT-NPN LIGBT exhibits an improved blocking capability and weak dependence of breakdown voltage(BV)on the P+anode doping concentration because the NPN structure suppresses triggering the PNP transistor.The proposed LIGBT reduces the E_(off)by 55%at the same V_(on),and improves the BV by 7.3%compared to the conventional LIGBT. 展开更多
关键词 snapback-free fast switching SOI LIGBT trench gate E_(off)
下载PDF
大型发电机组厂用电事故切换问题的探讨 被引量:1
15
作者 罗平 《湖北电力》 2004年第5期55-57,共3页
 大型发电机组高压厂用电自动切换存在的问题会导致厂用电事故扩大,其后果非常严重。为保证发电设备安全、可靠、稳定运行,对PZH 1A型微机厂用电快速切换装置事故切换所存在的问题进行探讨。
关键词 厂用电 BZT装置 快速切换
下载PDF
GIS隔离开关开合短母线型式试验方式1中VFTO测量系统构建及波形解析 被引量:7
16
作者 申萌 丁登伟 +1 位作者 李强 刘宸 《高压电器》 CAS CSCD 北大核心 2022年第7期207-213,共7页
开合短母线方式1试验是考核GIS隔离开关电气性能的关键型式试验之一。在方式1试验中,需要准确测量隔离开关在试验操作过程中所产生的全过程对地瞬态电压。为此文中构建了基于电容分压传感的超宽频瞬态电压测量系统,用于方式1试验。系统... 开合短母线方式1试验是考核GIS隔离开关电气性能的关键型式试验之一。在方式1试验中,需要准确测量隔离开关在试验操作过程中所产生的全过程对地瞬态电压。为此文中构建了基于电容分压传感的超宽频瞬态电压测量系统,用于方式1试验。系统包括VFTO传感器、监测终端以及控制单元,模拟带宽和系统采样率分别是100 MHz和250 MS/s。监测终端采用隔离变压器进行供电,有效提升了系统的抗干扰能力。文中以1100 kV GIS隔离开关作为试品,全过程监测了隔离开关方式1试验过程中交流侧和直流侧的瞬态电压波形。结合被试品的结构尺寸,分析了被试品两侧全过程瞬态电压的时域和频域特征。同时还分析了被试品的内部发生击穿时,隔离开关两侧所测电压信号的异常变化特征,形成了有效的内部击穿判据。通过1100 kV GIS隔离开关方式1试验,验证了文中所构建瞬态电压监测系统优异的测量和抗干扰性能,为GIS隔离开关的性能考核和优化设计提供了有力的支撑。 展开更多
关键词 GIS隔离开关 开合短母线 特快速瞬态过电压 超宽频电压测量 波形解析
下载PDF
A Quantitative LC-MS/MS Study of the Partitioning, Transport, and Fate of Pesticide Residues on Soil
17
作者 Heather A. Gamble Donald S. Gamble 《Journal of Environmental Protection》 2016年第3期331-340,共10页
Titration of pesticides onto sorption sites can determine sorption capacities on soils. Previous studies have tracked the sorption capacities and detailed kinetics of the uptake of atrazine and its decomposition bypro... Titration of pesticides onto sorption sites can determine sorption capacities on soils. Previous studies have tracked the sorption capacities and detailed kinetics of the uptake of atrazine and its decomposition byproduct hydroxyatrazine on different soils, including measurements made using LC-MS/MS. These studies have now been extended to explore sorption-desorption equilibria for a mixture of pesticides from soil using LC-MS/MS. Desorption of sorbed pesticide residues has environmental regulatory implications for pesticide levels in runoff, or for longer term sequestration, partitioning, and transport. The uptake of pesticides by the soil at equilibrium was measured for a number of different concentrations, and sorption capacities were estimated. Pesticide-soil interaction studies were conducted by exposing standard stock solutions of pesticide mixtures to a characterized Nova Scotia soil. The mixture contained atrazine and dicamba. Initial aqueous mixture concentrations ranging from 5 × 10<sup>-9</sup> to 10<sup>-5</sup> M or greater were exposed to 25 mg aliquots of soil and allowed to reach equilibrium. The total uptake of each pesticide was measured indirectly, by measuring the concentration remaining in solution using an IONICS 3Q 120 triple quadrupole mass spectrometer. These sorption capacities have been supplemented by studies examining equilibrium recovery rates from soil aliquots with different initial uptakes. This gives insight into the fraction of easily recoverable (reversibly sorbed) pesticides on the soil. Proper quantification of equilibrium constants and kinetic rate coefficients using high performance LC-MS/MS facilitates the construction of accurate, predictive models. Predictive kinetic models can successfully mimic the experimental results for solution concentration, labile sorption, and intra-particle diffusion, and could be used to guide regulatory practices. 展开更多
关键词 Pesticide-Soil Interactions Sorption Kinetics LC-MS/MS fast Polarity switching Predictive Modeling
下载PDF
岳城煤矿快切装置拒动故障分析与改进
18
作者 田志勇 《山西焦煤科技》 2016年第6期16-18,26,共4页
对于煤矿主通风机等大型设备,连续可靠的供电是保证煤矿安全的基本条件,工作电源与备用电源之间的快速切换是实现可靠供电的重要手段。分析了对岳城煤矿主通风机供电系统快切装置出现的两起典型拒动故障的原因,提出快切装置中新增"... 对于煤矿主通风机等大型设备,连续可靠的供电是保证煤矿安全的基本条件,工作电源与备用电源之间的快速切换是实现可靠供电的重要手段。分析了对岳城煤矿主通风机供电系统快切装置出现的两起典型拒动故障的原因,提出快切装置中新增"过流闭锁经方向"控制字,适当调整和选择整定值的改进措施,与传统的备用电源自动切换装置相比,有很大的优越性。 展开更多
关键词 快切装置 拒动故障 “过流闭锁经方向”控制字 整定值
下载PDF
光/蒸气协同构建交联多孔聚合物复合结构基超稳定高速阻变存储器
19
作者 班超逸 尹宇航 +9 位作者 罗旭 刘正东 陈康 唐明华 董雪梅 张登峰 李子凡 吴月悦 刘举庆 黄维 《Science China Materials》 SCIE EI CAS CSCD 2023年第5期2023-2031,共9页
有机阻变存储器由两个电极及夹在其间的阻变聚合物层组成,具有湿法制备和功能可调的优点.然而,该类存储器还存在结构稳定性差、开关速度慢和图案化困难等问题.在本文中,我们利用光/蒸汽协同方法制备了一种具有交联多孔复合结构的非晶态... 有机阻变存储器由两个电极及夹在其间的阻变聚合物层组成,具有湿法制备和功能可调的优点.然而,该类存储器还存在结构稳定性差、开关速度慢和图案化困难等问题.在本文中,我们利用光/蒸汽协同方法制备了一种具有交联多孔复合结构的非晶态聚合物薄膜,并将其作为阻变活性材料构建了一种具有高稳定性和高读取速度特征的存储阵列.所制备的聚合物二极管表现出非易失性的FLASH存储特性,具有高开关比、长维持时间以及快速信息写入(70 ns)和擦除(845 ns)等特征.令人印象深刻的是,该存储器件能够承受紫外辐射和极端温度等恶劣环境的考验.通过将存储阵列和特定传感器集成,构建了能模拟视觉/热感知和记忆功能的人造感知记忆系统,表明该系统在仿生神经形态电子领域具有巨大的应用潜力.该工作为制备具有高稳定性和高读取速度特征的聚合物存储阵列提供了一种可靠的策略. 展开更多
关键词 memristive polymer porous crosslink ultrastable operation fast switching sensory memory
原文传递
A high performance carrier stored trench bipolar transistor with a field-modified P-base region 被引量:2
20
作者 齐跃 汪志刚 +1 位作者 陈万军 张波 《Journal of Semiconductors》 EI CAS CSCD 2013年第4期54-59,共6页
A novel high performance carrier stored trench bipolar transistor (CSTBT) with a field- modified P-base region is proposed. Due to the p-pillars inserted into the drift region extending the P-base region to the bott... A novel high performance carrier stored trench bipolar transistor (CSTBT) with a field- modified P-base region is proposed. Due to the p-pillars inserted into the drift region extending the P-base region to the bottom of the trench gate, the electric field around the trench gate is modified, preventing the CSTBT from breakdown in advance caused by a concentration of the electric field at the edge of the trench gate. The p-pillars under the p-well forming the novel P-base region also provide extra paths for hole transportation. Thus, the switching time is also reduced. Simulation results have shown that the blocking voltage (BV) of the novel CSTBT is almost 430 V higher exhibiting avalanche breakdown properties compared with the conventional CSTBT. Moreover, the turn-off time of the novel structure is 0.3μs (17%) shorter than the conventional CSTBT with the same gate length. 展开更多
关键词 field-modified P-base region high breakdown voltage fast switching CSTBT
原文传递
上一页 1 2 下一页 到第
使用帮助 返回顶部