检索结果-内蒙古大学图书馆

2012 2nd International Conference on Electronic and Mechanical Engineering and Information Technology, EMEIT 2012

作者： Zhu, Xiaolin Gao, Qing Wang, Youtang Yu, Ming State Key Lab. of Automotive Simulation and Control Jilin University Changchun 130025 China Department of Thermal Energy Engineering Jilin University Changchun 130025 China College of Materials Science and Engineering Jilin University Changchun 130025 China

ISBN: (纸本)9789078677604

During long-time operation, thermal deformation of heat exchange pipe weaken the capability and reduce the reliability of heat transfer system, especially the heat exchange pipe with initial bending in high temperature storage condition will make problem more seriously. The finite element simulation study based on ABAQUS code was carried out to explore thermal deformation behavior of heat exchange pipe and interaction between pipe-soil interfaces, through establishing the typical initial bending model of pipe body and the description of the basic equations The distribution law of effective stress, displacement and plastic strain at feature edges and the cross section were obtained. The result showed that value of effective stress, displacement and plastic strain distribution of soil are cyclical fluctuation change with different bending deflection and bending direction, the location of maximum bending deflection is the most serious heat transfer attenuation areas. © the authors.

关键词： Finite element method

来源：评论

学校读者我要写书评

暂无评论

The study on measuring method of heat exchange pipe deformation and displacement based on thermal strain

The study on measuring method of heat exchange pipe deformat...

引用

2012 2nd International Conference on Electronic and Mechanical Engineering and Information Technology, EMEIT 2012

作者： Wang, Youtang Gao, Qing Zhu, Xiaolin Yu, Ming State Key Lab. of Automotive Simulation and Control Jilin University Changchun 130025 China Department of Thermal Energy Engineering Jilin University Changchun 130025 China College of Materials Science and Engineering Jilin University Changchun 130025 China

ISBN: (纸本)9789078677604

Thermal deformation of heat exchange pipe is the significant source of structural variation in ground heat exchange system, which could weaken the capability and reduce the reliability of heat transfer system after long-time operation. The experimental study of thermal deformation of heat exchange pipe should be carried out to explore its thermal behavior. The strain measuring method was applied to the study on thermal deformation and displacement, which was deduced from the measured strain in heat exchange pipe. The verifying experiment was carried out to analyse its feasibility in preliminary simulation environment. The result showed that strain measuring method is applicable and could be conducive to the deformation monitoring of heat exchange pipe in practical projects. © the authors.

关键词： Deformation

来源：评论

学校读者我要写书评

暂无评论

Equivalent capacity of the lower voltage ride through for wind farm from overcurrent protection in power collection lines

Equivalent capacity of the lower voltage ride through for wi...

引用

11th IET International Conference on Developments in Power Systems Protection, DPSP 2012

作者： Wang, Bin Dong, Xinzhou Bo, Zhiqian State Key Lab. of Control and Simulation of Power Systems and Generation Equipments Dept. of Electrical Engineering Tsinghua University Haidian District Beijing 100084 China Alstom Grid Stafford ST17 4LX United Kingdom

ISBN: (纸本)9781849196208

Magnitude and duration of voltage sags are the most important two factors to the Lower Voltage Ride Through (LVRT) capacity of the wind generator. Since most voltage sags are caused by the system faults, and sag durations are controlled by the tripping time of overcurrent relay in power collection lines based on the sags' magnitude. The specification of the LVRT capacity of wind generator is introduced into the operation characteristics of the relay in power collection lines. The evaluation model of equivalent LVRT capacity to overcurrent protection is proposed in paper, and the equivalent LVRT capacities from zone I and zone II relay are quantified. Improvement measures are also proposed.

关键词： Overcurrent protection

来源：评论

学校读者我要写书评

暂无评论

Positive-sequence component based three-phase unbalanced power flow solution for distribution system with PV nodes

引用

Zhongguo Dianji Gongcheng Xuebao/Proceedings of the Chinese Society of Electrical Engineering 2012年第1期32卷 115-121页

作者： Li, Hongwei Sun, Hongbin Zhang, An'an Liu, Qingyou State Key Laboratory of Oil and Gas Reservoirs Geology and Exploitation Southwest Petroleum University Chengdu 610500 Sichuan Province China State Key Lab. of Control and Simulation of Power Systems and Generation Equipments Dept. of Electrical Engineering Tsinghua University Haidian District Beijing 100084 China

The traditional power flow methods aren't appropriate to the electrical distribution systems with distributed generators (DG). Therefore, a direct unbalanced three-phase power flow algorithm was presented in this paper. The proposed approach which was developed based on the path matrix, utilized the special topological structure of distribution systems and established the incident matrix of node voltages and injection currents. Based on the assumption that the positive-sequence voltage magnitudes of PV nodes are invariable, the relation of reactive power and compensation voltage for the PV nodes had been derived by the positivesequence component and path matrix. As a result, a new approach handling PV nodes of DG had been proposed and could be integrated into the proposed power flow method. It needn't introduce any additional active power at PV nodes and kept the positive-sequence voltage magnitudes on their scheduled values, considering that reactive power limits were not violated. The results of the 6-bus and the 69-bus test systems verified the validity and universality of the proposed methods. © 2012 Chin. Soc. for Elec. Eng.

关键词： Reactive power

来源：评论

学校读者我要写书评

暂无评论

Application and benefit analysis of substation state estimation

引用

Dianli Xitong Baohu yu Kongzhi/Power System Protection and control 2012年第12期40卷 56-61页

作者： Li, Qing-Xin Wang, De-Xing Sun, Hong-Bin Wu, Wen-Chuan Wang, Jing Guo, Qing-Lai Zhang, Bo-Ming State Key Lab. of Control and Simulation of Power Systems and Generation Equipments Dept. of Electrical Engineering Tsinghua University Beijing 100084 China East China Electric Power Dispatch and Control Sub-Center East China Grid Company Limited Shanghai 200002 China

A substation three-phase nonlinear state estimation method based on zero impedance branches helps to identify topology and analogy errors at substation level and accordingly enhances the control center's state estimation reliability and accuracy. Some issues during the practical implementation process of the technology are reported, such as the hardware configuration, measurement integration, the communication between substation and control center, time setting and period selection. The benefits of the proposed technology have also been analyzed. It is shown that this technology has high reliability and low burden on communication, and improves the ability of monitoring of power grids and the reliability of the real-time power network model significantly. The proposed technology is verified effective by both simulation experiments and field-site applications in East China Power Grid, and is well qualified for real-time online applications, which has broad popularization and application prospects.

关键词： state estimation

来源：评论

学校读者我要写书评

暂无评论

A comprehensive rule based method for substation topology error identification

引用

Dianwang Jishu/Power System Technology 2012年第5期36卷 166-172页

作者： Wang, Jing Ge, Minhui Sun, Hongbin Li, Qingxin Wu, Wenchuan Guo, Qinglai Zhang, Boming State Key Lab. of Control and Simulation of Power Systems and Generation Equipments Dept. of Electrical Engineering Tsinghua University Haidian District Beijing 100084 China East China Electric Power Dispatch and Control Sub-Center East China Grid Company Limited Huangpu District Shanghai 200002 China

A substation topology error identification method based on comprehensive rules, including rules in different spatial scales such as element level, bay level and voltage level as well as rules in time sequence, is presented. Utilizing the superiority in multi-source, redundancy and rapid measurement in the substation, the multi spatial scale relevant rules of element, bay and voltage level as well as multi time sequence rules are proposed, and concrete implementation approach for such a method is given. The proposed method can improve the ability to identify the topology error, especially ability to identify switches without analog measurement, thus more reliable topological structure can be provided to control centre to improve the reliability of state estimation for the whole power system. Results of simulation and practical application show that the proposed method is effective.

关键词： Topology

来源：评论

学校读者我要写书评

暂无评论

Frequency dependent network equivalent based electromagnetic and electromechanical decoupled hybrid simulation

引用

Zhongguo Dianji Gongcheng Xuebao/Proceedings of the Chinese Society of Electrical Engineering 2012年第16期32卷 107-114页

作者： Zhang, Yi Wu, Wenchuan Zhang, Boming Gole, Aniruddha M. State Key Lab. of Control and Simulation of Power Systems and Generation Equipments Dept. of Electrical Engineering Tsinghua University Haidian District Beijing 100084 China Department of Electrical and Computer Engineering University of Manitoba Winnipeg R3T 5V6 Canada

Neither electromechanical transient stability analysis (TSA) program nor electromagnetic transient (EMT) programs can be used individually for the transient stability studies of the large scale AC/DC systems. This paper presented an electromagnetic and electromechanical hybrid simulation system, based on a frequency dependent network equivalent. Firstly, the framework and the main modules of the proposed hybrid simulation system were introduced. Secondly, the methods to calculate the equivalents of the electromagnetic side and the electromechanical side were introduced. The discussion on the difference between the traditional method and frequency dependent network equivalent (FDNE) and the flowchart of the hybrid simulation were also given. In the last part of the paper, AC system and AC-DC hybrid system are both used as examples to demonstrate the accuracy of the proposed hybrid simulation system's simulation results. © 2012 Chinese Society for Electrical Engineering.

关键词： Hybrid systems

来源：评论

学校读者我要写书评

暂无评论

Research on the effectiveness evaluation method of dynamic traffic information in UTFGS

Research on the effectiveness evaluation method of dynamic t...

引用

1st International Conference on Transportation Information and Safety: Multimodal Approach to Sustained Transportation System Development - Information, Technology, Implementation, ICTIS 2011

作者： Gao, Peng Yang, Zhaosheng Gao, Xueying College of Traffic and Transportation Jilin University Changchun 130022 China State Key Lab. of Automobile Dynamic Simulation Jilin University Changchun 130022 China

ISBN: (纸本)9780784411773

Traffic information has been dynamically provided by variable message signs (VMS), on-board equipment, traffic radio etc. in urban traffic flow guidance system (UTFGS) to help balance the traffic flow in the net, however, the impacts have not been well evaluated by taking the daily OD demand fluctuation in to consideration. Therefore, from discussing the impact of dynamic traffic information on driver's choice behavior and pointing out the key factors need to be considered, the paper proposes a realistic evaluation method of dynamic traffic information in considering of OD demand fluctuation and carries out a real urban network test for a week to show the possibility that the information provided in UTFGS may lead to a increase in total travel time. To sum up, it is confirmed that dynamic traffic information provision would not be effective under regular traffic condition except at the beginning of a peak;meanwhile, the benefit arises in unusual traffic condition caused by incidents. © 2011 ASCE.

关键词： Information management

来源：评论

学校读者我要写书评

暂无评论

A hierarchical control model for regional traffic signal coordination

A hierarchical control model for regional traffic signal coo...

引用

1st International Conference on Transportation Information and Safety: Multimodal Approach to Sustained Transportation System Development - Information, Technology, Implementation, ICTIS 2011

作者： Zhou, Huxing Yang, Zhaosheng Gao, Peng College of Traffic and Transportation Jilin University Changchun Jilin 130022 China State Key Lab. of Automobile Dynamic Simulation Jilin University Changchun Jilin 130022 China

ISBN: (纸本)9780784411773

In the traditional traffic control system, there is no coordination between different regions. This paper analyses the significance of coordination of the region boundary, brings out the condition for coordination and proposes two traffic control situation discrimination models of region boundary. After that, a dynamic hierarchical coordination control model of region boundary is proposed. Finally, a simulation test is carried out to validate the dynamic hierarchical coordination model with the help of VISSIM 4.2. Through evaluation index comparison of the traditional traffic control and the coordination model, it is concluded that the dynamic hierarchical coordination model is more efficient and produces better traffic control benefit than the traditional traffic control system. © 2011 ASCE.

关键词： control systems

来源：评论

学校读者我要写书评

暂无评论

Discriminant method of urban road traffic conditions based on cloud model

Discriminant method of urban road traffic conditions based o...

引用

1st International Conference on Transportation Information and Safety: Multimodal Approach to Sustained Transportation System Development - Information, Technology, Implementation, ICTIS 2011

作者： Yang, Qingfang Zhang, Biao State Key Lab. of Automobile Dynamic Simulation Jilin University Changchun Jilin 130022 China College of Traffic and Transportation Jilin University Changchun Jilin 130022 China

ISBN: (纸本)9780784411773

Urban road traffic conditions identifying can discriminate the road conditions using quantitative data of road network. A new urban road traffic conditions identifying method based on cloud model was proposed according to the cloud model's feature that it can achieve the natural conversion from quantitative data to qualitative concept;it can convert from the data of traffic parameters to traffic state smoothly. When classifying the regional traffic state, first, the state of intersections and links are classified respectively, second, with weighted average the state of intersections and links, the regional traffic state was given. A simulation was proposed by software VISSIM finally. A comparative analysis showed positive and encouraging results. © 2011 ASCE.

关键词： Roads and streets

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：