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TC网控楼UPS直流电压高关机定值的分析与改进
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作者 潘永成 曾海云 +1 位作者 杨楠 毛华兴 《中国设备工程》 2023年第S02期8-10,共3页
UPS不间断电源系统作为核电厂直接与停机停堆以及涉网相关的设备,对其安全供电可靠性有着很严苛的要求。在调试阶段,需要模拟各种工况对其UPS设备的供电可靠性进行验证,本文就针对某核电站调试阶段TC网控楼UPS设备进行上游交流电压阶跃... UPS不间断电源系统作为核电厂直接与停机停堆以及涉网相关的设备,对其安全供电可靠性有着很严苛的要求。在调试阶段,需要模拟各种工况对其UPS设备的供电可靠性进行验证,本文就针对某核电站调试阶段TC网控楼UPS设备进行上游交流电压阶跃试验时逆变器出现直流电压高关机切旁路运行的问题进行分析,以及后续通过相关模拟试验提出定值改进,以提高TC网控楼UPS设备的安全可靠性。 展开更多
关键词 UPS 阶跃 逆变器 直流电关机 切旁路运行
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高压(V_(DC)≤3kV)下测量陶瓷电容器电容量的装置
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作者 李文兴 成海鸥 朱鑫彦 《电子测试》 2016年第8期6-7,38,共3页
为了满足陶瓷电容器在高电压(直流)状态下(VDC≤3k V)进行实际电容量测试的需要,设计了一种高压下(VDC≤3k V)测试陶瓷陶瓷电容器电容量的简易装置。结果表明,该测量装置在测量陶瓷圆板电容器和陶瓷片式多层电容器电容量时,施加直流电... 为了满足陶瓷电容器在高电压(直流)状态下(VDC≤3k V)进行实际电容量测试的需要,设计了一种高压下(VDC≤3k V)测试陶瓷陶瓷电容器电容量的简易装置。结果表明,该测量装置在测量陶瓷圆板电容器和陶瓷片式多层电容器电容量时,施加直流电压不大于3k V时由于大电容的隔直效果好,容量测试的误差小,满足实际需要。 展开更多
关键词 陶瓷电容器 电容量 高直流电压 容量测试仪
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提高酸度计测量精度新方法的研究 被引量:4
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作者 甘平 胡国虎 《中国医学物理学杂志》 CSCD 2002年第1期30-32,共3页
本文从降低酸度计探头部分的系统误差、提高其测量精度的研究出发,提出了一种解决酸度计测量精度新的设计方法。而且这一新方法从理论上讲也适用于解决PH计之类的高内阻直流电压信号源的测量精度这一难题。为此,定义了一种全新的实用传... 本文从降低酸度计探头部分的系统误差、提高其测量精度的研究出发,提出了一种解决酸度计测量精度新的设计方法。而且这一新方法从理论上讲也适用于解决PH计之类的高内阻直流电压信号源的测量精度这一难题。为此,定义了一种全新的实用传感器电路类型—电荷耦合传感电路(3C电路),并用自行设计的电路证实了该方法的可行性和实用性。该新方法为大量计低成本地升级换代提供了一个新的途径,具有很大的经济和实用价值。 展开更多
关键词 酸度计(PH计) 测量精度 电荷耦合电路 内阻直流电信号源
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提高酸度计测量精度新方法的研究
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作者 甘平 胡国虎 《医疗卫生装备》 CAS 2001年第6期3-5,共3页
从降低酸度计探头部分的系统误差、提高其测量精度的研究出发,提出了一种解决酸度计测量精度新的设计方法。而且这一新方法从理论上讲也适用于解决pH计之类的高内阻直流电压信号源的测量精度这一难题。为此,定义了一种全新的实用传感器... 从降低酸度计探头部分的系统误差、提高其测量精度的研究出发,提出了一种解决酸度计测量精度新的设计方法。而且这一新方法从理论上讲也适用于解决pH计之类的高内阻直流电压信号源的测量精度这一难题。为此,定义了一种全新的实用传感器电路类型———电荷耦合传感电路(3C电路),并用自行设计的电路证实了该方法的可行性和实用性。该新方法为大量pH计低成本地升级换代提供了一个新的途径,具有很大的经济和实用价值。 展开更多
关键词 酸度计 测量精度 PH计 电荷耦合电路 内阻直流电信号源
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Development and Prospect of China Power Grids 被引量:1
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作者 赵遵廉 《Electricity》 2004年第1期6-11,共6页
In this paper the growing process of China power grid from formation of local power grids to nationwide interconnection is reviewed. The scale and structure of power grid construction in the near future, especially th... In this paper the growing process of China power grid from formation of local power grids to nationwide interconnection is reviewed. The scale and structure of power grid construction in the near future, especially the planning on sending power from west to east, North-South supplementation and nationwide interconnection are introduced. In addition, the technologies to be extended in future grid development are briefed, such as HVDC, FACTS and compact transmission line, etc. 展开更多
关键词 power grid PLANNING in terconnection transmission technology
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A 1V,156.7μW,65.9dB Rail-to-Rail Operational Amplifier by Means of Negative Resistance Load and Replica-Amplifier Gain Enhancement 被引量:2
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作者 刘爱荣 杨华中 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2006年第12期2101-2105,共5页
A low-voltage, low-power, and high-gain rail-to-rail operational amplifier (OpAmp) is presented. The replica-amplifier gain enhancement technique is applied to improve the DC gain of the amplifier, which does not de... A low-voltage, low-power, and high-gain rail-to-rail operational amplifier (OpAmp) is presented. The replica-amplifier gain enhancement technique is applied to improve the DC gain of the amplifier, which does not degrade the output swing and is very suitable for low-voltage applications. In a 0. 18/μm standard CMOS process,a 1V OpAmp with rail-to-rail output is designed. For a load capacitance of 5 pF,simulation by HSPICE shows that this OpAmp achieves an effective open-loop DC gain of 65. 9dB,gain bandwidth of 70.28 MHz,and phase margin of 50 with a quiescent power dissipation of 156.7μW. 展开更多
关键词 low-voltage low-power high DC gain replica-amplifier gain enhancement negative resistance load
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Modern Travelling Wave Based Fault Location Techniques for HVDC Transmission Lines 被引量:6
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作者 陈平 徐丙垠 +1 位作者 李京 葛耀中 《Transactions of Tianjin University》 EI CAS 2008年第2期139-143,共5页
The modern travelling wave based fault location principles for transmission lines are analyzed.In order to apply the travelling wave principles to HVDC transmission lines,the special technical problems are studied.Bas... The modern travelling wave based fault location principles for transmission lines are analyzed.In order to apply the travelling wave principles to HVDC transmission lines,the special technical problems are studied.Based on this,a fault locating system for HVDC transmission lines is developed.The system can support modern double ended and single ended travelling wave princi- ples simultaneously,and it is composed of three different parts:travelling wave data acquisition and processing system,communication network and PC based master station.In the system,the fault generated transients are induced from the ground leads of the over-voltage suppression capacitors of an HVDC line through specially developed travelling wave couplers.The system was applied to 500 kV Gezhouba-Nanqiao(Shanghai)HVDC transmission line in China.Some field operation experiences are summarized,showing that the system has very high reliability and accuracy,and the maximum location error is about 3 km(not more than 0.3%of the total line length). Obviously,the application of the system is successful,and the fault location problem has finally been solved completely since the line operation. 展开更多
关键词 fault location global positioning system HVDC transmission lines REPEATERS
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High voltage DC leakage detection for double-lined hazardous waste landfill based on finite element method
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作者 赵晓慈 张以都 +1 位作者 杨萍 能昌信 《Journal of Shanghai University(English Edition)》 CAS 2007年第6期585-590,共6页
According to the structural characteristics of hazardous waste landfill, a new model based on the finite element method (FEM) is developed. The detection layer is considered as a sealed space and it is assumed that ... According to the structural characteristics of hazardous waste landfill, a new model based on the finite element method (FEM) is developed. The detection layer is considered as a sealed space and it is assumed that total current flows through the leak for the high resistivity of geomembrane liner. The leak current is regarded as a positive point current +I and the other current source is -I. Electrical potential of an arbitrary point in detection layer satisfies Poisson equation. Experiments for detecting leaks in liner were carried out. Excellent agreement between experimental data and simulated model data validates the new model. Parametric curves for a single leak show that with optimum selection of field survey parameters leaks can be detected effectively. For multiple leaks, the simulated results indicate that they are detectable when leak separation is larger than measurement spacing. 展开更多
关键词 double-liner landfill leakage detection finite element method (FEM) parameter curve.
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Study on Transmission Planning of Cascade Hydropower Stations along Lancang River Basin
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作者 Cui Wenjia Du Zhongming Dai Jianfeng 《Electricity》 2012年第1期26-31,共6页
Most of the hydropower projects in Southwest China and the adjacent foreign regions will be put into operation between 2015 and 2020, which will bring some difficulties for reasonable accommodation and delivery of ele... Most of the hydropower projects in Southwest China and the adjacent foreign regions will be put into operation between 2015 and 2020, which will bring some difficulties for reasonable accommodation and delivery of electric energy. In this paper the author studies the development scale, development schedule, accommodation and transmission schemes of the cascade hydropower stations along the Lancang River basin, one of the five large basins in China, based on the load characteristics of grids at both the sending end and the receiving end, the strategy of complementary utilization of thermal power and hydropower, the advanced transmission technologies, and the optimal economic performance. The study results show that, the cascade hydropower stations on the upper reaches of the Lancang River in Yunnan should mainly serve Guangdong Province, with proper planning of partly serving Yunnan Province during dry seasons. The transmission schemes should adopt UHVDC, UHVAC, and single-tower double-circuited HVDC transmission scheme according to the transmission capacity and distance. 展开更多
关键词 hydropower station transmission scheme electric energy accommodation
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Research on Multi Level Dynamic Voltage Compensator based on MMC
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作者 Runfeng Zhang 《International Journal of Technology Management》 2014年第1期38-40,共3页
The modular multilevel converter (MMC) is a highly modular, easy to expand; the output voltage waveform is good, especially suitable for application in high voltage power system. This article first introduces the ci... The modular multilevel converter (MMC) is a highly modular, easy to expand; the output voltage waveform is good, especially suitable for application in high voltage power system. This article first introduces the circuit topology and principle of MMC, and the main technical characteristics of MMC. And according to the relationship between the drop power voltage and the load power factor, proposed three working modes of the minimum energy compensation strategy. It is shown that MMC has good application prospect in future medium or high- voltage high power applications, especially be one of candidates for HVDC system application. 展开更多
关键词 Voltage sag MMC cascade multilevel technology compensation strategy
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Research on Common Grounding Electrode Technique in HVDC
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作者 Chenglian MA 《International Journal of Technology Management》 2015年第1期4-6,共3页
This paper discusses the characteristics of DC transmission common system ground electrode type and shared ground electrode, established the mathematical model of two circuit DC systems share ground electrode, analyze... This paper discusses the characteristics of DC transmission common system ground electrode type and shared ground electrode, established the mathematical model of two circuit DC systems share ground electrode, analyze effects of the shared loop ground DC transmission system electrode on the operation of HVDC system size under different operation modes, and compare with the independent ground electrode, ground electrode impact on environment under different operation mode, and the paper finally puts forward some solving measures for the influence of the shared ground electrode on the environment and public ground electrode effects on DC system operation problems. 展开更多
关键词 HVDC ground electrode line protection DC transmission system TRANSIENT
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Research on Intelligent Control and protection of flexible HVDC
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作者 Runfeng Zhang 《International Journal of Technology Management》 2014年第2期29-31,共3页
This paper introduces the working principle of HVDC control and protection system. And the paper summarizes the flexible HVDC technology features and application fields and describes the composition and software intel... This paper introduces the working principle of HVDC control and protection system. And the paper summarizes the flexible HVDC technology features and application fields and describes the composition and software intelligent flexible HVDC control and protection system configuration. Finally, the simulation results are also given, experimental results show: HVDC flexible intelligent control and protection has a good control effect in the steady state and transient process, suitable for practical engineering application. 展开更多
关键词 Flexible DC transmission Pulse Wide Module Intelligent control
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Stability Enhancement and Blackout Prevention by VSC Based HVDC
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作者 Ying Jiang-Hafner Rolf Palsson +3 位作者 Malin Agren Thomas Nordlander Pehr Hjalmarsson ManfredManchen 《Journal of Energy and Power Engineering》 2012年第11期1891-1900,共10页
This paper deals with the operation and performance of VSC (voltage source converter) based HVDC (high voltage direct current) interconnecting two extremely weak AC networks, the experience of Caprivilink project.... This paper deals with the operation and performance of VSC (voltage source converter) based HVDC (high voltage direct current) interconnecting two extremely weak AC networks, the experience of Caprivilink project. It is shown in the paper that the HVDC converter automatically provides the supreme voltage and frequency stabilizing function when a critical situation is detected, no matter the disturbances appeared in sending end or receiving end AC networks. This supreme voltage and frequency stabilizing function makes it possible to avoid the blackout even if all the generators are tripped under an extra-ordinary worst contingency. By plots of recorded transients, the paper will show how the eventual blackouts are avoided. 展开更多
关键词 HVDC VSC transmission system BLACKOUT weak AC system stability.
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Sealed model and computation of hazardous waste landfill high voltage DC leakage detection
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作者 杨萍 Tian Jinwen +1 位作者 Wang Yanni Xue Lin 《High Technology Letters》 EI CAS 2015年第4期457-464,共8页
According to the structural characteristics of hazardous waste landfill and the leakage current model of high voltage DC Landfill leakage detection, a sealed model is established detail. The detection layer of the haz... According to the structural characteristics of hazardous waste landfill and the leakage current model of high voltage DC Landfill leakage detection, a sealed model is established detail. The detection layer of the hazardous waste landfill is considered as a sealed assumed that the source current flows through the leak entirely. The leak is regard and analyzed in space and it is ed as a positive current resource + I located at the current entrance or a negative resource - I located at the current exit, which depends on the placement of the current supply. The electrical potential of an arbitrary in detection layer satisfies Poisson equation. The boundary condition is regarded as a natural bound- ary condition for the high resistivity of high density polyethylene (HDPE) membrane. Based on which a numerical calculation method is developed. Satisfactory agreement between experimental da- ta and simulated data validates the analysis. Parametric studies show that a larger horizontal distance between the power supply electrode and leak and a smaller distance between the detector electrodes and the detected liner are helpful to leak location. More parametric curves show that parameters leaks can be detected effectively with optimum selection of field survey. 展开更多
关键词 hazardous waste landfill high voltage DC method sealed space model
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Brushless Doubly-Fed Induction Machine as a Variable Frequency Transformer
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作者 Ayman Abdel-Khalik Ahmed Elserougi +1 位作者 Ahmed Massoud Shehab Ahmed 《Journal of Energy and Power Engineering》 2013年第1期110-117,共8页
VFT (variable frequency transformer) has been recently used as art alternative to HVDC (high voltage direct current) to control power flow between asynchronous networks. VFT consumes less reactive power than a bac... VFT (variable frequency transformer) has been recently used as art alternative to HVDC (high voltage direct current) to control power flow between asynchronous networks. VFT consumes less reactive power than a back-to-back HVDC system, provides faster initial transient recovery, and has better natural damping capability. VFT is simply a DFIM (doubly-fed induction machine) where the machine torque controls the power flow from stator to rotor and vice versa. The main disadvantage of this VFT is the slip rings and brushes required for the rotor circuit, especially in bulk power transmission. The BDFM (brushless doubly-fed machine) with nested cage rotor machine is proved to be a comparable alternative to conventional DFIM in many applications with the advantage that all windings being in the stator frame with fixed output terminals. In this paper, the BDFM is used as a BVFT (brushless variable frequency transformer). A prototype machine is designed and simulated to verify the system validity. 展开更多
关键词 Variable frequency transformer brushless doubly-fed machines AC machines induction machine.
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FPGA-Based Real-Time Simulation of Modular Multilevel Converter HVDC Systems
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作者 Luc-André Grégoire Jean Bélanger Wei Li 《Journal of Energy and Power Engineering》 2012年第7期1119-1125,共7页
AC-HVDC-AC energy conversion systems using MMC (modular multilevel converters) are becoming popular to integrate distributed energy systems to the main grid. Such multilevel converters pose a serious problems for H... AC-HVDC-AC energy conversion systems using MMC (modular multilevel converters) are becoming popular to integrate distributed energy systems to the main grid. Such multilevel converters pose a serious problems for HIL (hardware in the loop) simulators required for control, protection design and testing due to the large number of cells that must be simulated individually using very small time steps. This paper demonstrates the advantages of using a very small time step to simulate a MMC topology. The MMC is implemented on FPGA (fiel-programmable gate array) to simulate fast transient with a time step of 250 ns. The AC network and HVDC bus is simulated on the PC, with a slower time step of 10 μs to 20 μs. The simulator architecture and the components simulated on the FPGA and on the PC will be discussed, as well as the method allowing the interconnection of this slow and fast system. 展开更多
关键词 FPGA simulation modular multi-level voltage source converters (MMC) MMC converter real-time simulation HIL(hardware-in-the-loop).
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Flexible HVDC Transformer for Next Generation Renewable Energy Industry
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作者 Chong Ng Paul McKeever 《Journal of Energy and Power Engineering》 2013年第9期1625-1633,共9页
The growing demand on non-fossil fuel energy has escalated the desire for mega-scale renewable energy power generation, which can no longer be satisfied solely by relying on onshore renewable energy power plants. Outc... The growing demand on non-fossil fuel energy has escalated the desire for mega-scale renewable energy power generation, which can no longer be satisfied solely by relying on onshore renewable energy power plants. Outcomes from a recent project funded by the Sixth European Union Framework Programme (FP6), Project "Upwind" concluded that larger offshore wind turbines (i.e., 〉 10 MW) are feasible and cost effective. It will be beneficial for such future large scale renewable energy power generators (i.e., large offshore turbines) and plant (i.e., large offshore wind farms) to have a dedicated high efficiency, robust, flexible and low cost power collection, transmission and distribution technology. Proposed in this paper is a compact and effective hybrid HVDC (high voltage direct current) transformer that allows realisation of a highly robust and financially rewarding next generation multi-terminal HVDC system for future offshore renewable energy power plant. This concept, potentially, allows the elimination or minimisation of the need for a centralised local offshore HVDC platform or substation in each wind farm, solar farm, or tidal farm. This paper discusses the study outcome of the proposed hybrid HVDC transformer and the application of a multi-terminal HVDC system in the renewable energy industry, compared to the existing HVAC and VSC (voltage source converters) type HVDC systems. 展开更多
关键词 HVDC WIND power OFFSHORE SUBSTATION PV (photovoltaic) VSC.
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Research on the control method for voltage-current source hybrid-HVDC system 被引量:13
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作者 GUO ChunYi LIU WenJing ZHAO ChengYong 《Science China(Technological Sciences)》 SCIE EI CAS 2013年第11期2771-2777,共7页
The hybrid-HVDC topology,which consists of line-commutated-converter(LCC)and voltage source converter(VSC)and combines their advantages,has extensive application prospects.A hybrid-HVDC system,adopting VSC on rectifie... The hybrid-HVDC topology,which consists of line-commutated-converter(LCC)and voltage source converter(VSC)and combines their advantages,has extensive application prospects.A hybrid-HVDC system,adopting VSC on rectifier side and LCC on inverter side,is investigated,and its mathematic model is deduced.The commutation failure issue of the LCC converter in the hybrid-HVDC system is considered,and a novel coordinated control method is proposed to enhance the system commutation failure immunity.A voltage dependent voltage order limiter(VDVOL)is designed based on the constant DC voltage control on the rectifier side,and constant extinction angle backup control is introduced based on the constant DC current control with voltage dependent current order limiter(VDCOL)on the inverter side.The hybrid-HVDC system performances under normal operation state and fault state are simulated in the PSCAD/EMTDC.Then,system transient state performances with or without the proposed control methods under fault condition are further compared and analyzed.It is concluded that the proposed control method has the ability to effectively reduce the probability of commutation failure and improve the fault recovery performance of the hybrid-HVDC system. 展开更多
关键词 line commutated converter (LCC) voltage source converter (VSC) hybrid-HVDC system voltage dependent voltageorder limiter (VDVOL) constant extinction angle backup control commutation failure
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A Spectral Method for the Electrohydrodynamic Flow in a Circular Cylindrical Conduit 被引量:1
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作者 Mohsen MOGHTADAEI Hassan SABERI NIK Saeid ABBASBANDY 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2015年第2期307-322,共16页
This paper presents a combination of the hybrid spectral collocation technique and the spectral homotopy analysis method(SHAM for short) for solving the nonlinear boundary value problem(BVP for short) for the electroh... This paper presents a combination of the hybrid spectral collocation technique and the spectral homotopy analysis method(SHAM for short) for solving the nonlinear boundary value problem(BVP for short) for the electrohydrodynamic flow of a fluid in an ion drag configuration in a circular cylindrical conduit. The accuracy of the present solution is found to be in excellent agreement with the previously published solution. The authors use an averaged residual error to find the optimal convergence-control parameters. Comparisons are made between SHAM generated results, results from literature and Matlab ode45 generated results, and good agreement is observed. 展开更多
关键词 Spectral collocation Spectral homotopy analysis method Optimal convergence-control parameters Electrohydrodynamic flow
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Modeling of an ionized electric field on the building near the UHVDC transmission line 被引量:8
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作者 ZHEN YongZan CUI Xiang LU TieBing 《Science China(Technological Sciences)》 SCIE EI CAS 2014年第4期747-753,共7页
In this paper,a 3D upstream finite element method is developed to analyze the ionized electric field around the UHVDC transmission lines including the building near it.The ionized electric field around the building is... In this paper,a 3D upstream finite element method is developed to analyze the ionized electric field around the UHVDC transmission lines including the building near it.The ionized electric field around the building is reduced due to the shielding effect of the building and the shielding distance is about three times its height.The ionized electric field including the human body model on the building and away from the building is also taken into account.The ionized electric field distortion ratio of the human body model is discussed in this paper.The distortion ratios for the positions on the building are less than those on the ground. 展开更多
关键词 BUILDING finite element method (fem) human body HVDC ionized electric field
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