检索结果-内蒙古大学图书馆

A voltage control strategy for preventing cascading trips of large-scale wind power in centralized area

Dianli Xitong Zidonghua/Automation of Electric power systems 2014年第11期38卷 7-12页

作者： Ding, Tao Guo, Qinglai Sun, Hongbin Xu, Fengda Xu, Xiaofei Jia, Lin Department of Electrical Engineering Tsinghua University Beijing China State Key Laboratory of Control and Simulation of Power Systems and Generation Equipments Tsinghua University Beijing China North China Power Grid Co. Ltd. Beijing China

Cascading wind farm trips have brought new challenge to the wind power integration. Traditional reactive power optimization can achieve a desirable control result, but voltage security violation usually happens after N-1 contingency because of the redistribution of power flow and slow response by the reactive power compensator. Therefore, a reactive power optimization model is set up with security constraints, aiming to maintain the voltage within the security region under both normal condition and N-1 contingency. Besides, Benders decomposition method is employed to solve the complex model, dividing into one master and some slave problems. Iterative method is used between master and slave problems to obtain the optimal solution. Practical power grid with nine wind farms is tested, and the comparison of security constrained optimal power flow (SCOPF) and traditional optimal power plow shows that the SCOPF has better effect, which can maintain the voltage security under both normal condition and N-1 contingency. So it is an effective method to prevent cascading faults of multiple wind farms integrated into power grid. Finally, the relationship of maximum wind power integration, wind farm capacity and reactive power capacity of wind units is fully studied to provide certain help for the operation of wind farm. ©2014 state Grid Electric power Research Institute Press

关键词： Wind farm

来源：评论

学校读者我要写书评

暂无评论

Expectative Modeling of Wide-area Damping Networked control systems with Long Stochastic Time Delay

Expectative Modeling of Wide-area Damping Networked Control ...

引用

第25届中国控制与决策会议

作者： Zhang Xinran Lu Chao Han Yingduo State Key Laboratory of Control and Simulation of Power System and Generation Equipments Tsinghua University

ISBN: (纸本)9781467355339

In this paper, the impact of stochastic time delay on wide-area damping networked control systems is analyzed. A disintegrate method of time-delay upon sampling period is approved. Furthermore, the expectative model of networked control systems with long and stochastic time delay, whose variance extent is larger than one sampling period, is theoretically proved and calculated. Finally, the effectiveness of this expectative model is confirmed on the simulation of a power system with 8 generators and 36 nodes.

关键词： Networked control system, Wide Area Damping control, Long Stochastic Time Delay, Expectative Model.

来源：评论

学校读者我要写书评

暂无评论

Dynamic simulation based on Jacobian-free Newton-GMRES methods with adaptive preconditioner for power systems

引用

Science China(Technological Sciences) 2013年第8期56卷 2037-2045页

作者： HUANG ShaoWei CHEN Ying SHEN Chen MEI ShengWei State Key Laboratory of Control and Simulation of Power Systems and Generation Equipments(Department of Electrical Engineering Tsinghua University)

Dynamic simulation is one of the most complex and important computations for power systems *** solutions based on normal Newton iterations almost all depend on evaluations of Jacobian matrixes,which increases the programming complexity of and limits the parallelizability of the whole *** this paper,a new adaptive preconditioned Jacobian-free Newton-GMRES(m)method is proposed to be applied to dynamic simulations of power *** new method has totally Jacobian-free characteristics,which saves calculations and storages of Jacobian matrixes and features strong ***,several speedup strategies are introduced to enhance efficiency and parallelizability of overall *** tests are carried out on IEEE standard test systems and results show that in series computing environment,simulations based on the proposed method have comparable speed to those based on classical Newton-Raphson methods.

关键词： dynamic simulation Newton-GMRES preconditioner power system

来源：评论

学校读者我要写书评

暂无评论

Low-carbon power grid index system and evaluation method

引用

Dianli Xitong Zidonghua/Automation of Electric power systems 2014年第17期38卷 157-162页

作者： Sun, Yanlong Kang, Chongqing Chen, Songsong Meng, Junxia Lu, Chang Luo, Jinshan Department of Electrical Engineering Tsinghua University Beijing100084 China State Key Laboratory of Control and Simulation of Power Systems and Generation Equipments Tsinghua University Beijing100084 China China Electric Power Research Institute Beijing100192 China State Power Economic Research Institute Beijing102209 China

The importance of establishment of the low-carbon power grid index system and its comprehensive evaluation model for the development of the low-carbon power grid is firstly discussed. Based on the concept of life cycle analysis, a comprehensive low-carbon power grid index system and a more refined central index system are designed in consideration of different aspects of coverage, and the meaning of each index explicated in detail. Furthermore, a comprehensive evaluation method is designed for the quantization of the low-carbon developing condition of different power grids. Finally, an example analysis is conducted based on the statistical data of some domestic power grids to demonstrate the actual application of the evaluation model. © 2014 state Grid Electric power Research Institute Press

关键词： Electric power transmission networks

来源：评论

学校读者我要写书评

暂无评论

Design optimization of ferrite rings for VFTO mitigation

引用

IEEE Transactions on power Delivery 2014年第99期PP卷 1-1页

作者： He, Jiaxi Guan, Yonggang Liu, Weidong Chen, Weijiang Li, Zhibing Department of Electrical Engineering State Key Lab of Control and Simulation of Power Systems and Generation Equipment Tsinghua University Beijing100084 China State Grid Corporation of China Beijing100031 China China Electric Power Research Institute Beijing100192 China

Very-fast transient overvoltage (VFTO)-related problems are raising growing concerns in China with the development of ultra-high voltage. The practice of fitting ferrite rings on gas-insulated switchgear busbars for VFTO mitigation has long been proposed but few investigations on its design optimization were conducted. Based on theoretical analysis of the simplified model, the optimal damping condition of ferrite rings is proposed, which is conducive to the type selection. The number of rings to be employed to ensure visible suppressing effects is given through simulations and the influence of the saturation is discussed. Impact on the power frequency is analyzed to be negligible. Finally, comparisons aremade between the theoretical conclusions and existing experiment results, which approve the optimal damping condition and agree with the number of rings to be employed. © 2014 IEEE.

关键词： Electric switchgear

来源：评论

学校读者我要写书评

暂无评论

Discussion on tower shunt coefficient of UHV DC transmission line under lightning stroke

Discussion on tower shunt coefficient of UHV DC transmission...

引用

International Conference on Lightning Protection (ICLP)

作者： S Chen J Hu B Zhang Y Yin M Hua State Key Lab of Control and Simulation of Power Systems and Generation Equipment Tsinghua University Beijing China China Electric Power Research Institute Beijing China Tibet Electric Power Research Institute Lhasa China

ISBN: (纸本)9781479935451

The development of UHV transmission technology brings longer transmission distance, higher towers and more complicated terrain along the transmission lines, which make the shunt performance of transmission line under lightning stroke more diversiform compared to conventional ones. This paper discusses the effects of factors, such as lightning current waveform, footing resistance, transmission line span etc., on the shunt coefficient of UHV DC transmission lines, which is of great significance for setting out lightning-proof measures as well as the location of lightning stroke point. It is referred that lightning current waveform especially its front time as well as tower footing resistance plays a significant role in determine of the tower shunt coefficient under lightning stroke. As the results indicates, the shunt coefficient of ground wire gets larger as the footing resistance increases while it decreases first and then increases as the front time of the lightning current waveform increases. The shunt coefficient of tower is just the opposite.

关键词： EMTDC Educational institutions Poles and towers Wires Wide area networks Lightning

来源：评论

学校读者我要写书评

暂无评论

Simplified mathematical model of inter-turn short circuit of field windings in hydro-generators and its application

引用

Science China(Technological Sciences) 2013年第4期56卷 898-909页

作者： HAO LiangLiang WU JunYong SUN YuGuang WANG XiangHeng School of Electrical Engineering Beijing Jiaotong University State Key Lab of Control and Simulation of Power Systems and Generation Equipment Tsinghua University

Inter-turn short circuit of field windings is a common electrical fault of *** is an important method of investigating the fault and providing data support for fault ***,huge numbers of pole pairs and damper loops in large hydro-generators would lead to lengthy calculation time,hindering scientific research and engineering *** deal with this problem,we analyze a theoretical basis for a damper winding simplified model and then propose an equivalent treatment *** the analysis of steady-state current harmonic characteristics of generators with different stator winding configurations during the fault,the simplified models suitable for steady-state calculation are derived from two aspects,namely,additional rotor harmonic current frequency characteristics and the relationship of the amplitude as well as the phase of each branch current of the *** calculation and experimental results of the two simplified models are then compared to verify the models' correctness.A calculation example of the Three Gorges left bank VGS generator shows few deviations between the calculation results of the simplified model and the original ***,the calculation time using the simplified model is 1/1500 that using the original model,which provides a more effective tool for on-line fault ***,the sensitivity-verification application of the fault-monitoring scheme based on the stator steady-state unbalanced current RMS is *** result shows that the scheme can monitor two-turn short circuits of field windings in the Three Gorges generator and provide high sensitivity.

关键词： hydro-generator field windings inter-turn short circuit simplified model on-line monitoring

来源：评论

学校读者我要写书评

暂无评论

Modeling and analysis of unit commitment considering RCAES system

Modeling and analysis of unit commitment considering RCAES s...

引用

Chinese control Conference (CCC)

作者： Bin Liu Laijun Chen Yu Zhang Chen Fang Shengwei Mei Yuan Zhou State Key Lab of Control and Simulation of Power Systems and Generation Equipment Tsinghua University Beijing Beijing CN Electric Power Research Institute State Grid Shanghai Municipal Electric Power Company China Key Laboratory of Cryogenics Technical Institute of Physics and Chemistry Chinese Academy of Sciences Beijing CN

Regenerative compressed air energy storage (RCAES) system is a practical and efficient solution to large-scale integration of renewable energy problems faced by power systems currently. Appropriately modeling of RCAES system is critical to its practical application, whereas research in this area has been very limited. According to the energy storage and transformation process, a concise model of RCAES system applicable to power scheduling field is proposed. Then, a unit commitment model with RCAES system is formulated as a MILP problem which can be accurately solved with high computation efficiency by CPLEX. A modified IEEE 39 bus system is used to study the impacts of parameters of RCAES system on unit commitment and the effectiveness of the proposed model is then validated. Furthermore, the proposed model can also be employed to optimize key parameters of RCAES system, e.g. efficiency and capacity of each part in an integrated way.

关键词： Energy storage Heating Computational modeling Wind power generation power grids Schedules

来源：评论

学校读者我要写书评

暂无评论

采用Fisher判别法对GIS中局部放电类型的识别(英文)

引用

高电压技术 2013年第4期39卷 805-812页

作者： DING Dengwei GAO Wensheng LIU Weidong State Key Laboratory of Control and Simulation of Power System and Generation Equipment Department of Electrical EngineeringTsinghua University

To monitor the condition of online power apparatus accurately and provide appropriate guidance on their maintenance,a fundamental ultra-high frequency(UHF) database of partial discharges corresponding to different types of defects is presented for the observation of insulation state of gas insulated switchgear(GIS).In order to imitate the defects in a GIS online,five types of typical partial discharge(PD) sources(*** metal,protrusion,bouncing particles,void in spacer,and particle on the surface of solid insulation) were designed and fabricated.A wideband UHF sensor and an amplifier were applied to obtain UHF *** on the characteristics of the five different defects,nine meaningful parameters which were independent of the phase of the applied voltage were extracted from the PD samples and then *** this paper,Fisher discriminant analysis(FDA),a pattern recognition algorithm,was applied for the purpose of classifying the *** this way,there was no need to set complicated parameters and kernel function,and the total discrimination accuracy of test samples was 97.6%.It indicates that based on the nine especial parameters,the typical defects in GIS can be identified exactly by means of *** the analysis method could be possibly regarded as a universal classification method.

关键词： Fisher判别分析绝缘缺陷局部放电 GIS 气体绝缘开关地理信息系统在线监测识别算法

来源：评论

学校读者我要写书评

暂无评论

Nanopowder production by gas-embedded electrical explosion of wire

引用

Chinese Physics B 2013年第4期22卷 350-353页

作者：邹晓兵毛志国王新新江伟华 State Key Laboratory of Control and Simulation of Power System and Generation Equipments Department of Electrical Engineering Tsinghua University Department of Physics and Chemistry College of Science North China University of Technology

A small electrical explosion of wire （EEW） setup for nanopowder production is constructed. It consists of a low inductance capacitor bank of 2 μF–4 μF typically charged to 8 kV–30 kV, a triggered gas switch, and a production chamber housing the exploding wire load and ambient gas. With the EEW device, nanosize powders of titanium oxides, titanium nitrides, copper oxides, and zinc oxides are successfully synthesized. The average particle size of synthesized powders under different experimental conditions is in a range of 20nm–80nm. The pressure of ambient gas or wire vapor can strongly affect the average particle size. The lower the pressure, the smaller the particle size is. For wire material with relatively high resistivity, such as titanium, whose deposited energy Wd is often less than sublimation energy W s due to the flashover breakdown along the wire prematurely ending the Joule heating process, the synthesized particle size of titanium oxides or titanium nitrides increases with overheat coefficient k （k = W d /Ws ） increasing.

关键词： electrical explosion of wire nanosized powders particle size

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：