共查询到18条相似文献，搜索用时 93 毫秒
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分析了医院环境中浪涌产生的原因,以及在医疗设备和控制系统、计算机数据、病人和医护人员生命安全等方面的危害.指出了医院环境中电力浪涌防护的解决方案. 相似文献
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RCD型缓冲吸收电路仿真与实验研究 总被引：2，自引：0，他引：2
程一玮 《北京工业职业技术学院学报》2011,10(2):5-9
浪涌电压抑制是大功率逆变器设计过程中需要重点考虑的因素,设置缓冲电路是抑制浪涌电压的一种有效方法。首先分析了浪涌电压在IGBT开关过程中的成因,讨论了几种常见的缓冲吸收电路类型,详细分析了RCD限幅钳位型缓冲电路的工作原理,并给出了其参数计算的具体公式。仿真与实验结果表明RCD限幅钳位型缓冲电路可以有效地抑制IGBT开关过程中的浪涌电压,保护IGBT工作在安全工作区。 相似文献
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介绍了浪涌抗扰度实验的基本情况和现状,分析了浪涌抗扰度实验中振铃波信号电路中各元件对振铃波的影响,介绍一种产生振铃波信号的基本电路,对电路进行模拟,采集了大量的实验数据,并进行数据处理。然后进行电路实验,从而进一步验证得出相关结论,达到了设计的要求和目的。 相似文献
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曾睿 《中国石油大学胜利学院学报》2021,(2):34-37
浪涌保护器在石油化工装置中的应用主要体现在两个方面:一是限制雷电感应、雷电侵入波等产生的瞬时过电压;二是使由线路传送而来的雷电流得以泄放,从而达到保护电气或电子系统的目的.通过对浪涌保护器定义、分类和参数选取等内容的详细分析,结合石油化工装置项目的实际案例,指出在石化供电系统中浪涌保护器的合理选择方式,使浪涌保护器发挥... 相似文献
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孙晓婷 《宁德师专学报(自然科学版)》2007,19(2):119-122
分析了感应加热装置中逆变器的功率器件IGBT关断时浪涌电压产生的原因以及4种关断缓冲电路中功率器件通断时电路的工作过程和特点，给出了选取缓冲电路的注意事项． 相似文献
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电力系统频率是电力系统运行参数中最重要的参数之一,对系统频率控制的分析与研究是电力系统安全运行中一个不可忽视的环节。本文介绍了电力系统频率控制的基本概念及其特性,结合青海电网实际运行特性分析了影响青海电网频率的各种因素,在此基础上提出了青海电网频率控制策略。 相似文献
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应用Matlab／Simulink中的电力系统元件库SimPowerSystems构建电力系统仿真模型,设置了模型中各元件参数并对该电力系统发生多种短路故障进行仿真与分析．结果表明,其结果符合实际理论,波形能够准确直观地考察电力系统故障的动态特性．另外,通过不同故障问的仿真对比与分析可知,三相短路故障是电力系统中最为严重的故障,在实际生产生活中要极力避免．由此说明Matlab是电力系统仿真研究的有力工具． 相似文献
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袁宏 《江西电力职业技术学院学报》2013,26(1):38-41
电网全部或部分因故障停电后,采用黑启动方案,通过系统具有启动能力的机组,可迅速恢复供电。本文介绍了上犹江水电厂的黑启动实践,并根据该厂运行情况就下列几个方面进行了论述:一是机组调频调压带厂用电;二是机组递升加压开机恢复厂用电;三是通过柴油机带厂用电;四是零启动电源送电恢复厂用电;五是等待电网恢复电压后由系统倒送电或启动机组恢复厂用电。 相似文献
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瞬态电压抑制器在开关电源中的应用 总被引：1，自引：0，他引：1
姚文华 《南阳师范学院学报》2006,5(9):30-32
描述了瞬态电压抑制器(TVS管)的工作原理和性能参数,以及在开关电源电路中的应用和选管要求。 相似文献
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杨建湘 《广西梧州师范高等专科学校学报》2014,(2):143-146
介绍了一种用于织物表面处理常压低温等离子体电源的工作原理及控制方法。根据纺织物表面处理工艺要求,高压电源采用前级PWM控制Buck电路DC／DC变换,后级H桥逆变经变压器升压结构产生稳定、均匀、柔和的低温等离子体。自动调节以计算机为控制单元,利用传感器技术实现自动控制,提高电源的可靠性。实际应用等离子体高频高压电源在纺织材料中的结果表明：该技术在提高了电源效率的同时,快速有效地抑制浪涌电压和峰值电流,改善了纺织材料表面处理的性能。 相似文献
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It is imperative to develop a risk assessment system for quickly predicting storm surge disaster due to the vulnerability of Tianjin Binhai New Area. The flood routing model with user-defined breaches was firstly established based on the seed spread algorithm in order to achieve a rapid forecasting of storm surge flood information. Furthermore, fuzzy mathematics was utilized to identify the storm disaster grade, and the hazard mapping was conducted to visually obtain the hazard spatial and temporal distribution. Finally, the flood routing visualization method was proposed based on numerical simulation of storm surge to achieve the reappearance scene of dynamic evolution process. The developed system can play a vital role in the management and decision-making of sea dyke mitigation engineering in Tianjin Binhai New Area. 相似文献
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新颖的正激式高频环节交-交变换器(英文) 总被引：1，自引：0，他引：1
提出新颖的正激式高频环节交交变换器电路结构和电路拓扑族 ,这类电路结构由输入周波变换器、高频变压器、输出周波变换器以及输入、输出滤波器构成 ,电路拓扑族包括全桥全波式等8种电路 .深入研究了这类变换器的双极性移相控制策略和稳态原理 ,获得了外特性曲线 .采用具有输出周波变换器与输入周波变换器之间移相、输出周波变换器换流重叠、输出滤波电感电流和输入电压极性选择的双极性移相控制策略 ,这类交交变换器的周波变换器上的尖峰电压和环流得到抑制 .这类变换器具有电路拓扑简洁、两级功率变换 (低频交流 /高频交流 /低频交流 )、双向功率流、高频电气隔离、输出波形质量好和稳压能力强等优点 ,为实现新型的正弦交流稳压器和电子变压器奠定了关键技术基础 .原理试验很好地证实了这类变换器的正确性和先进性 . 相似文献
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荆淑萍 《辽宁科技学院学报》2004,6(1):28-31
介绍本钢铁业公司电动鼓风机及控制系统概况,对ABB公司Freelnce2000DCS自动控制系统在高炉鼓风机上的应用进行了简介,对防喘振调节,做了详细分析和探讨,并对这套系统的设计存在的不足提出了改进的措施. 相似文献
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Theoretical and technical research in structural equation modeling (SEM) focuses on the procedures per se rather than on substantive applications of the procedures. An earlier bibliography annotated nearly 300 technical publications about latent variable models. Since that bibliography was published in 1991, there has been a distinct surge in theoretical‐technical publications, organized around model evaluation, multifaceted extensions to levels, groups, and occasions, ordinal level data, statistical power, categorical data, and new computer programs (Mx, MECOSA, RAMONA, SEPath). This article updates the earlier bibliography to acknowledge the growth of more specialized refinements of SEM and to guide developers, researchers, and instructors. As an indicator of the surge in this literature, over 320 new publications are annotated in this version within a 9‐part categorization system. The groupings were selected to be reasonably exhaustive and not too extensive, resulting in this set: (a) Model Specification and Identification, (b) Model Estimation (including asymptotics), (c) Model Testing, Evaluation, and Modification, d) Monte Carlo/Simulation, (e) Reviews and Critiques/Debates, (0 Introductory and Pedagogical, (g) Philosophical, (h) Special Purpose Models (e.g., multitrait‐multimethod, multilevel, behavior genetics, developmental/change), and (i) Computer Programs and Programming. 相似文献
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A two-dimensional numerical model of extratropical storm surge and inundation in Bohai Bay was built based on the unsteady flow Navier-Stokes equations. The model included two sections, one was for the simulation of storm surge tidal level and the other for the simulation of storm surge inundation in the coastal area. While simulating the storm surge tidal level, the alternating direction implicit (ADI) method was applied to dispersing and solving 2D storm surge equations. In the simulation of storm surge inundation, the 2D unsteady flow equations were dispersed and solved using the structureless grids of finite volume method (FVM). A coupling calculation mode of the process of inundation and storm surge tidal level variation was proposed, therefore the storm surge inundation process and area could be calculated while simulating and forecasting the process of storm surge tidal setup. Furthermore, an extratropical storm surge and inundation in Bohai Bay were simulated using this numerical model. Simulation results are in good agreement with the measured data, which shows that this numerical model provides a new method of simulating and forecasting storm surge and inundation in Bohai Bay. 相似文献