检索结果-内蒙古大学图书馆

Traveling-wave-based fault location in electrical distribution systems with digital simulations

Telkomnika (Telecommunication Computing Electronics and Control) 2014年第2期12卷 297-304页

作者： Tang, Jinrui Yin, Xianggen Zhang, Zhe State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and Technology Luoyu Road 1037 Wuhan 430074 Hubei Province China

Traveling-wave-based fault location in electrical distribution systems is an important safeguard for the distribution network reliability. The effectiveness of the methods is verified directly in power grid in the early stages, while different fault types can't appear in a short time. And normal dynamic physical simulation cannot meet the teaching demand either because of the limitation of transmission line model and other factors. So PSCAD/EMTDC and MATLAB are used to illustrate the the fault location methods in this paper, which can promote the traveling-wave-based fault-location technology. Meanwhile, the traveling-wave-based fault-location method based on characteristic frequencies is analyzed in this paper.

关键词： Electric lines

来源：评论

学校读者我要写书评

暂无评论

Numerical Simulation on the Production Mechanism of Surface-Wave Plasmas Sustained along a Metal Rod

引用

Chinese Physics Letters 2014年第3期31卷 103-106页

作者： ZHU Long-Ji CHEN Zhao-Quan YIN Zhi-Xiang WANG Guo-Dong XIA Guang-Qing HU Ye-Lin ZHENG Xiao-Liang ZHOU Meng-Ran CHEN Ming LIU Ming-Hai College of Electrical and Information Engineering Anhui University of Science and Technology Huainan 232001 State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and Technology Wuhan 430074 State Key Laboratory of Structural Analysis for Industrial Equipment Dalian University of Technology Dalian 116024

For interpreting the production mechanism of surface-wave plasmas sustained along a metal rod, electromagnetic simulation on the electromagnetic field distributions and particle-in-cell/Monte Carlo collision （PIC/MCC） simulation of the ionization process are present. The results show that the enhanced electric field of surface plasmon polaritons （SPPs） can be excited in the ion sheath layer between the negative-voltage metal rod and the surface-wave plasmas, which is responsible for maintaining the plasma discharge. Moreover, the spatio-temporal evolutions of plasma density and electric fields are simulated by the PIC/MCC model. It is further suggested that the expanded ion sheath layer can extend the length of plasma domain by increasing the plasma absorbed energy from SPPs.

关键词： SURFACE waves (Fluids) RESEARCH PLASMA (Ionized gases) -- Research ELECTROMAGNETISM electromagnetic theory PHYSICS research

来源：评论

学校读者我要写书评

暂无评论

Transmission Network Expansion Planning Considering Uncertainties in Loads and Renewable Energy Resources

引用

CSEE Journal of Power and Energy Systems 2015年第1期1卷 78-85页

作者： Jinyu Wen Xingning Han Jiaming Li Yan Chen Haiqiong Yi Chang Lu State Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Electrical and Electronic EngineeringHuazhong University of Science and TechnologyWuhan430074China China South Power Grid International Co. LTDGuangzhou510080China State Power Economic Research Institute Beijing102209China

This paper proposes a novel method for transmission network expansion planning(TNEP)that take into account uncertainties in loads and renewable energy *** goal of TNEP is to minimize the expansion cost of candidate lines without any load curtailment.A robust linear optimization algorithm is adopted to minimize the load curtailment with uncertainties considered under feasible expansion ***,the optimal planning scheme obtained through an iterative process would be to serve loads and provide a sufficient margin for renewable energy *** this paper,two uncertainty budget parameters are introduced in the optimization process to limit the considered variation ranges for both the load and the renewable *** results obtained from two test systems indicate that the uncertainty budget parameters used to describe uncertainties are essential to arrive at a compromise for the robustness and optimality,and hence,offer a range of preferences to power system planners and decision makers.

关键词： Expansion planning renewable generation robust linear optimization transmission network uncertainty

来源：评论

学校读者我要写书评

暂无评论

Finite Element Method Applied to Fuse Protection Design

引用

Plasma Science and technology 2014年第3期16卷 294-299页

作者：李森宋执权张明许留伟李金超傅鹏王敏董琳 College of Electrical and Electronic Engineering Huazhong University of Science and Technology State Key Laboratory of Advanced Electromagnetic Engineering and Technology Institute of Plasma Physics Chinese Academy of Sciences China International Nuclear Fusion Energy Program Execution Center

In a poloidal field （PF） converter module, fuse protection is of great importance to ensure the safety of the thyristors. The fuse is pre-selected in a traditional way and then verified by finite element analysis. A 3D physical model is built by ANSYS software to solve the thermal- electric coupled problem of transient process in case of external fault. The result shows that this method is feasible.

关键词： PF converter thyristor protection fuse verification finite element method

来源：评论

学校读者我要写书评

暂无评论

Generating wind power time series based on its persistence and variation characteristics

引用

Science China(Technological Sciences) 2014年第12期57卷 2475-2486页

作者： LI Jing Hua LI Jia Ming WEN Jin Yu CHENG Shi Jie XIE Hai Lian YUE Cheng Yan China State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and TechnologySchool of Electrical and Electronic Engineering School of Electrical Engineering Guangxi University ABB (China) Ltd. Corporate Research Center

Generation of wind power time series is an important foundational task for assisting electric power system planning and mak- ing decision. By analyzing the characteristics of wind power persistence and variation, th!.s paper proposes an improved Mar- kov chain Monte Carlo （MCMC） method, identified as the PV-MC method, for the direct generation of a synthetic series of wind power output. On the basis of the MCMC method, duration time and variation features are concluded in PV-MC method, gaining a more comprehensive reflection of wind power characteristics in the generated wind power time series. First, the wind power state series is generated to meet the state transition matrix based on the definition of the wind power state. Then, the time duration of each state in the series is determined by its respective duration character. Finally, the variation characteristic is used to convert the state series to a wind power time series. A significant amount of simulations are performed based on the PV-MC and MCMC methods and are then compared for 25 wind farms at 6 different locations throughout the world. The sim- ulation results show that the PV-MC method offers an excellent fit for the time domain features （persistence and variation characteristic） while holding other statistic features （mean value, variance, autocorrelation coefficient （ACC） and probability density function （PDF）） close to the MCMC method.

关键词： wind power time series generation persistence characteristic variation characteristic markov chain monte carlomethod

来源：评论

学校读者我要写书评

暂无评论

Research on fast solid state DC breaker based on a natural current zero-crossing point

引用

Journal of Modern Power Systems and Clean Energy 2014年第1期2卷 30-38页

作者： Wang XIANG Yu HUA Jinyu WEN Meiqi YAO Naihu LI State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and TechnologyWuhan 430074China Alstom Grid China Technology Center(CTC) Minhang DistrictShanghai 201114China

The DC fault characteristics of voltage source converter based high voltage direct current(VSC-HVDC)systems are analyzed in this *** phenomenon whereby the capacitor on DC side discharges quickly during a DC fault contributes to a large short-circuit fault *** traditional DC breakers nor DC switches can cut off the fault current under this condition.A fast solid state DC breaker design method is proposed in this *** method is based on the fault current characteristics of the inverter in multi-terminal HVDC systems(MTDC),where a fault current appears at the natural zerocrossing point near the *** this point,by coordinating the AC breakers near the rectifier,the DC breaker could reliably cut off the DC fault current and protect the system.A detailed model for this fast solid state DC breaker and its operation sequence are studied,based on this design *** modeling a five-terminal meshed DC grid and a fast DC breaker were carried out with PSCAD/EMTDC using this design *** results from the simulations confirmed the validity of the design method.

关键词： VSC-HVDC Multi-terminal HVDC DC short circuit fault DC breaker

来源：评论

学校读者我要写书评

暂无评论

Multi-band microwave metamaterial absorber based on coplanar Jerusalem crosses

引用

Chinese Physics B 2014年第1期23卷 437-442页

作者：王国栋刘明海胡希伟孔令华程莉莉陈兆权 State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and Technology Wuhan 430074 China School of Physics Huazhong University of Science and Technology Wuhan 430074 China College of Electrical and Information Engineering Anhui University of Science and Technology Huainan 232001 China

The influence of the gap on the absorption performance of the conventional split ring resonator(SRR) absorber is investigated at microwave frequencies. Our simulated results reveal that the geometry of the square SRR can be equivalent to a Jerusalem cross(JC) resonator and its corresponding metamaterial absorber(MA) is changed to a JC absorber. The JC MA exhibits an experimental absorption peak of 99.1% at 8.72 GHz, which shows an excellent agreement with our simulated results. By simply assembling several JCs with slightly different geometric parameters next to each other into a unit cell, a perfect multi-band absorption can be effectively obtained. The experimental results show that the MA has four distinct and strong absorption peaks at 8.32 GHz, 9.8 GHz, 11.52 GHz and 13.24 GHz. Finally, the multi-reflection interference theory is introduced to interpret the absorption mechanism.

关键词： Jerusalem cross multi-band metamaterial absorber multi-reflection interference theory

来源：评论

学校读者我要写书评

暂无评论

Operating Parameters Optimization of SMES Considering Transient Thermal Stability

Operating Parameters Optimization of SMES Considering Transi...

引用

IEEE International Conference on Applied Superconductivity and electromagnetic Devices

作者： Kang Gong Jing Shi Li Ren Yin Xu Yi Zhang Yang Liu Li Hui Zhang Xiao Zhou Ao Bo Zhou State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and Technology

ISBN: (纸本)9781467381086

In this paper, an operating parameters optimization method for SMES considering transient thermal stability is proposed. Firstly, based on the analysis of transient thermal characteristics of SMES, a neural network based transient thermal analysis model is established to test the transient thermal stability of SMES for particular application scenarios. Then, based on the proposed model, a procedure is designed to find the best operating parameters of SMES, which can maintain the transient thermal stability of HTS magnet and meet the demand of power system as far as possible. Finally, the effectiveness of operating parameters optimization for SMES are verified by co-simulation based on MATLAB and COMSOL.

关键词： Component SMES Reliability Transient thermal stability Current maintain

来源：评论

学校读者我要写书评

暂无评论

Research on the security risk assessment system for regional complex power grid

Research on the security risk assessment system for regional...

引用

International Conference on Electric Utility Deregulation and Restructuring and Power Technologies (DRPT)

作者： Faqi Yan Yang Wang Xianggen Yin Jinhui Li Wen Yang Biao Xu Cheng Jian Central China Electric Power Dispatching and Control Sub-center of State Grid Wuhan Hubei Province China State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and Technology Wuhan China

In order to guarantee the safe and stable operation of the complex power grid and prevent wide-area blackouts, safety and risk assessment of power grid, which is carried out by charge of the third party independent evaluation agency, is an important means of safety risk management and conducive to satisfy the respective requirements and interests of government, power enterprise and power user. Besides, it will promote the progress of deregulation of power grid under the present electric power system. Considering the current situation of regional power grids of China and the requirement of power grid security risk control, this paper introduces the framework and methods of safety and risk assessment for large power grid and analyzes one case of the application in a trans-provincial regional power grid of China.

关键词： Decision support systems Power industry Risk management Power systems Radio frequency

来源：评论

学校读者我要写书评

暂无评论

Design of a DC Busbar for the ITER PF Converter

引用

Plasma Science and technology 2014年第4期16卷 406-409页

作者：郭斌宋执权许留伟张明李金超蒋力傅鹏王敏董琳 College of Electrical and Electronic Engineering Huazhong University of Science and Technology State Key Laboratory of Advanced Electromagnetic Engineering and Technology Institute of Plasma Physics Chinese Academy of Sciences China International Nuclear Fusion Energy Program Execution Center

The DC busbar is an important component for the ITER PF converter module to connect the converter and the reactor. This paper analyzes different cross-sections and different thermodynamic properties under natural-cooling and water-cooling conditions, and simulation is carried out by the software of the finite element method （FEM）. The result of the analysis shows that the water-cooling method is the better choice for the DC busbar.

关键词： cross-section temperature natural-cooling water-cooling DC busbar

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：