检索结果-内蒙古大学图书馆

A massive grid-connected power accumulator battery testing system using hybrid AC-DC microgrid

Diangong Jishu Xuebao/Transactions of China Electrotechnical Society 2014年 29卷 449-453页

作者： Long, Bo Sun, Hongbin Wang, Bin Yao, Shuqing Fang, Xu Yao, Gaoxiang University of Electronic Science and Technology Chengdu610054 China State Key Laboratory of Control and Simulation of Power System and Generation Equipments Tsinghua University Beijing100084 China Bohai New Century Machinery Manufacturing Co. Ltd. TianJin300280 China

Nowadays, the network mode of the most energy recovery power battery testing instruments adopts AC-microgrid, which has the drawbacks of low energy recovery efficiency, complicated power circuit topology, cumbersome of the control algorithms. Aiming at these issues, a hybrid AC-DC microgrid system which is based on the power battery testing system has been put forward in this paper. The proposed scheme is composed by an energy storing system, a bidirectional DC-DC converter for test experiment, the grid-side loads, compared with conventional scheme, the proposed scheme has the merits of higher energy recovery efficiency, simplified power circuit for testing instruments. ©, 2014, Diangong Jishu Xuebao/Transactions of China Electrotechnical Society. All right reserved.

关键词： DC-DC converters

来源：评论

学校读者我要写书评

暂无评论

Fast evaluation of the lightning electromagnetic field in the time domain with an adaptive piecewise approximation of channel base current

Fast evaluation of the lightning electromagnetic field in th...

引用

作者： Lee, Jae-Bok Zou, Jun Li, Mo Chang, Sughun Electrical Environment Research Center Korea Electrotechnology Research Institute Changwon Korea Republic of State Key Lab. of Control and Simulation of Power Systems and Generation Equipments Department of Electrical Engineering Tsinghua University Beijing China

Purpose - A fast algorithm is proposed to calculate the lightning electromagnetic field over a perfectly conducting earth surface. Design/methodology/approach - The channel base current is approximated by a number of sub-domain quadratic functions using the proposed adaptive sampling technique, and the derivative and integral of the channel base current with respect to time can be analytically expressed. With the help of these approximations, the ideal electromagnetic field of the lightning channel can be evaluated along the lightning channel with respect to the height. Findings - The computational time can be greatly reduced using the proposed approach to evaluate the electromagnetic field of a lightning channel in the time domain. Originality/value - The adaptive sampling technique is a general-purposed approach, which can be potentially used in other applications to fit a function with the minimal number of intervals. © Emerald Group Publishing Limited.

关键词： Electromagnetic fields

来源：评论

学校读者我要写书评

暂无评论

Nonlinear model predictive control for path following problems

引用

International Journal of Robust and Nonlinear control 2014年第8期25卷

作者： Shuyou Yu Xiang Li Hong Chen Frank Allgöwer Department of Control Science and Engineering Jilin University Changchun China Institute for Systems Theory and Automatic Control University of Stuttgart Stuttgart Germany State Key Laboratory of Automotive Simulation and Control Jilin University Changchun China

This paper presents a general nonlinear model predictive control scheme for path following problems. Path following problem of nonlinear systems is transformed into a parameter-dependent regulation problem. Sufficient conditions for recursive feasibility and asymptotic convergence of the given scheme are presented. Furthermore, a polytopic linear differential inclusion-based method of choosing a suitable terminal penalty and the corresponding terminal constraint are proposed. To illustrate the implementation of the nonlinear model predictive control scheme, the path following problem of a car-like mobile robot is discussed, and the control performance is confirmed by simulation results. Copyright © 2014 John Wiley & Sons, Ltd.

关键词： model predictive control nonlinear systems path following feasibility and convergence

来源：评论

学校读者我要写书评

暂无评论

Research on generation and execution of coordination strategy for bi-directional and interactive coordinated voltage control between provincial and district levels

引用

Dianwang Jishu/power System Technology 2013年第12期37卷 3426-3432页

作者： Wang, Bin Guo, Qinglai Sun, Hongbin Li, Haifeng Luo, Jianyu Zhang, Boming Wu, Wenchuan State Key Lab of Control and Simulation of Power Systems and Generation Equipments Dept. of Electrical Engineering Tsinghua University Haidian District Beijing 100084 China Jiangsu Electrical Power Dispatching and Control Center Nanjing 210024 Jiangsu Province China

To achieve the goal of bi-directional and interactive coordinated voltage control between provincial and district levels, the study is focused generation and execution of coordination strategy for bi-directional and interactive coordinated voltage control between provincial and district levels. Firstly, the method to generate the bi-directional and interactive coordination strategy between provincial and district levels is proposed, and the gateway coordination state transition diagram is designed to intuitionally express the criterion of the interaction between the AVC systems belonging to the upper and lower level systems respectively;then, the regularization method for expanded coordinated secondary voltage control suitable to provincial power network and the regularization method suitable to district power network are put forward respectively to realize mutual support between power networks in provincial level and district level. Results from simulation examples and on-site operations show that the proposed method is feasible and effective as well.

关键词： Electric power transmission networks

来源：评论

学校读者我要写书评

暂无评论

Resistance Characteristics of Arc in Long Air Gap

引用

高电压技术 2013年第8期39卷 1881-1885页

作者： YU Zhanqing YU Junjie ZENG Rong CHEN He PENG Xiang State Key Laboratory of Control and Simulation of Power System and Generation Equipments Department of Electrical Engineering Tsinghua University Beijing 100084 China Maintenance and Test Center of EHV Power Transmission Company China Southem Power Grid Co. Ltd. Guangzhou 510663 China

Arc resistance is an important parameter for characterizing long arcs in air, and its laboratory testing is of importance for accurate arc modeling of electromagnetic transient caused by short circuit fault. Therefore, we constructed an experimental system to study the cha- racteristics of long AC arc in air. Driven by currents of 10 kA or 40 kA (root mean square value), the system produces arcs with different initial lengths of 1 m, 2 m and 4 m, and the movement of the arcs are captured by a high-speed camera. After performing experiments using the system, we carried out analysis and comparisons of the arc resistance of arcs with different lengths and different currents, as well as a study of the relationship between the macro-morphology and the resistance of the arcs. Conclusions were drawn from the experimental re- sults: the arc voltage had obvious saturation characteristics; the arc resistance increased with the increase of arc length and the decrease of current; the arcs bended or extended significantly in time and the peak arc voltage within a single cycle increased correspondingly; the arcs had voltage and current in the same phase. In the end, a formula of arc resistance based on the experiment results is derived.

关键词：耐电弧性电阻特性空气间隙实验室测试电流驱动实验系统初始长度电弧电压

来源：评论

学校读者我要写书评

暂无评论

Estimation of the electromechanical characteristics of power systems based on a revised stochastic subspace method and the stabilization diagram

引用

Science China(Technological Sciences) 2012年第6期55卷 1677-1687页

作者： NI JingMin SHEN Chen LIU Feng State Key Laboratory of Control and Simulation of Power Systems and Generation Equipments Beijing 100084China

Estimating low-frequency oscillation modes and the corresponding mode shapes based on ambient data from WAMS measurements has a promising prospect in power system analysis and *** on the stochastic subspace method,this paper proposes a revised stochastic subspace method by introducing reference channels,which can estimate the modes and the mode shapes simultaneously with great computational ***,the accuracy of the estimated results is not *** discriminate the real modes from the spurious ones,the stabilization diagram is introduced.A novel algorithm is designed to deal with the stabilization diagram which can detect the real modes *** conducted on the IEEE-118 system indicate that the proposed method has good performance in terms of both computational efficiency and accuracy,and has the potential of being used on-line.

关键词： electromechanical oscillation ambient data stochastic subspace method reference channels stabilization diagram

来源：评论

学校读者我要写书评

暂无评论

Numerical Analysis of Space Charge Characteristics in Low-density Polyethylene Nanocomposite under External DC Electric Field

Numerical Analysis of Space Charge Characteristics in Low-de...

引用

中国物理学会第十八届全国静电学术会议

作者： ZHOU Yuanxiang ZHANG Ling SHA Yanchao TIAN Jihuan State Key Laboratory of Control and Simulation of Power System and Generation Equipments Tsinghua University ABB (China) Limited Universal

In this work, we are interested in space charge dynamics characteristics in the low-density polyethylene(LDPE) nanocomposite mixed with some mass fraction of inorganic nanofillers. Different with all previous qualitatively theoretical works, numerical simulation based on the bipolar charge transport model was performed to systematically investigate the influence of trap depth, trap concentration, and injection barrier height on the space charge and electric field distributions under DC external electric field of 100 k V/mm. Our simulation results showed that increasing the trap depth would severely distort the electric field distribution at the balanced status with the highest and lowest electric field of 119 k V/mm and 47 k V/mm, respectively. Due to the introduction of nanofillers, more deep traps were created and blocked the space charge movement, capturing most of space charge in the vicinity of the electrode and largely declining the local electric field further. In addition, our theoretical analysis also showed both the high permittivity and low local electric field contributed to the increase of injection barrier height. Once the injection barrier height surpassed 1.25 e V, there was almost no charge that could overcome the injection barrier. At last, a mechanism of space charge suppression in the LDPE nanocomposite was presented.

关键词： LDPE nanocomposite space charge bipolar charge transport model trap depth Schottkyinjection barrier height

来源：评论

学校读者我要写书评

暂无评论

Tube MPC scheme based on robust control invariant set with application to Lipschitz nonlinear systems

引用

systems & control Letters 2013年第2期62卷 194-200页

作者： Shuyou Yu Christoph Maier Hong Chen Frank Allgöwer Department of Control Science and Engineering Jilin University PR China Institute for Systems Theory and Automatic Control University of Stuttgart Germany State Key Laboratory of Automotive Simulation and Control Jilin University PR China

The paper presents a tube model predictive control (MPC) scheme of continuous-time nonlinear systems based on robust control invariant sets with respect to unknown but bounded disturbances. The cost functional of the optimization problem is not necessarily quadratic. The scheme has the same online computational burden as the standard MPC with guaranteed nominal stability. Robust stability, as well as recursive feasibility, is guaranteed if the optimization problem is feasible at the initial time instant. In particular, we consider a scheme to obtain robust control invariant sets for a class of Lipschitz nonlinear systems, and to show the effectiveness of the proposed schemes by a simple example.

关键词： Robust model predictive control Robust invariant set Bounded disturbances Lipschitz nonlinear systems

来源：评论

学校读者我要写书评

暂无评论

Comparison of Two Basic Structures in Magnetically-Coupled Resonant Wireless power Transfer

Comparison of Two Basic Structures in Magnetically-Coupled R...

引用

第十五届中国科协年会

作者： ZHANG Yiming ZHAO Zhengming CHEN Kainan State Key Lab of Control and Simulation of Power Systems and Generation Equipments Department of Electrical EngineeringTsinghua UniversityBeijing 100084China

Wireless power transfer (WPT) has been a research focus in recent *** on magnetically-coupled resonant wireless power transfer (MCR-WPT),this paper made a comparison of 2 basic structures in MCR-WPT,namely the 2-coil structure and the 4-coil *** equivalent electric circuits were *** illuminate the difference between these 2 structures,the input impedance,the transfer efficiency,and the load matching were studied and verified by experimental *** conclusion can be drawn that without reducing the transfer efficiency,the additions of the source coil and the load coil in the 4-coil structure make it easier for the system to perfectly match the source and the load.

关键词： wireless power transfer magnetic resonance comparison structure

来源：评论

学校读者我要写书评

暂无评论

Optimization of the magnetic property of a magnetorheological squeeze mount

Optimization of the magnetic property of a magnetorheologica...

引用

FISITA 2012 World Automotive Congress

作者： Zhang, Xinjie Ma, Fangwu Zhao, Fuquan Guo, Konghui Ahmadian, Mehdi State Key Laboratory of Automotive Simulation and Control Jilin University Jilin China Zhejiang Geely Automobile Research Institute Co. Ltd. Zhejiang China Center for Vehicle Systems and Safety Virginia Tech. Blacksburg VA 24060 United States

ISBN: (纸本)9783642338342

Magneto-rheological fluid squeeze mode investigations have shown that MR fluids show large force capabilities in squeeze mode and it can be used for isolating vibration. An MR squeeze mount's magnet system will be designed and optimized in this research. An FEM model of the magnetic supply system of a Magnetorheological squeeze mount is developed and the parameters are studied firstly. And then, the magnetic property is optimized by the co-simulation of the Matlab and FEMM, which will be used to improve the range of the damping of a Magnetorheological squeeze mount. At last, a mathematical model for this magnetic system is proposed for solving the applied current in the real time control. © Springer-Verlag 2013.

关键词： Sensitivity analysis

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：