检索结果-内蒙古大学图书馆

2011 International Conference on Electrical, Information Engineering and Mechatronics, EIEM 2011

作者： Cheng, Shan Chen, Min-You Fleming, Peter J. Li, Xia State Key Laboratory of Power Transmission Equipment and System Security and New Technology School of Electrical Engineering Chongqing University Chongqing China Department of Automatic Control and Systems Engineering University of Sheffield Sheffield United Kingdom

ISBN: (纸本)9781447124665

This study presents the optimal allocation of distributed generators (DGs) in distribution network based on an adaptive multi-objective particle swarm optimization (AMPSO). In order to enable the DGs to make the best contribution to the distribution network, a multi-objective optimization model addressing power loss and a voltage stability index (VSI) is constructed, in which the capacity factor of DGs is taken into consideration. In the AMPSO, some adaptive techniques including the use of dynamically changing inertia weight, time-varying acceleration coefficients, mutation operation and circular crowding sorting have been integrated to improve the convergence and the diversity performance of the algorithm. The proposed algorithm has been used to determine the optimal allocation of DGs in a IEEE 33-bus distribution network. simulation results show that the proposed method can identify the optimal solutions with a good tradeoff between the power loss and the VSI. © 2012 Springer-Verlag London Limited.

关键词： Multiobjective optimization

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

A compact coaxial gas filled switch

A compact coaxial gas filled switch

引用

IEEE International Conference on Plasma Science (ICOPS)

作者： Xiaobing Zou Xinjing Cai Xinxin Wang Department of Electrical Engineering State Key Laboratory of Control and Simulation of Power System and Generation Equipment Tsinghua University Beijing China College of Electrical Engineering Northeast Dianli University Jilin China

Summary form only given. As we know, the risetime of the output voltage of a pulse power generator is mainly determined by the performance of the main discharge switch. Recently, to calibrate nanosecond pulse voltage dividers, A nanosecond pulse generator with an output voltage of 2–10 kV was constructed. The generator was composed of a DC charging source, a 50 Ohm coaxial cable as a pulse forming line (PFL), a self-breakdown coaxial gas filled switch, a 50 Ohm coaxial cable as pulse transmission line (PTL), and a matched load. The gas filled switch with two plate electrodes was made as compact as possible to reduce the switch inductance. The gap distance of the switch is fixed to be ∼0.5mm and filled with pressurized nitrogen gas. Extensive tests were made to measure the risetime of the output voltage as the filled gas pressure changed from 0.1MPa ∼0.6Mpa. the averaged risetime of the output voltage is ∼14 ns as the switch gas pressure is set to be 0.1MPa, while the risetime is ∼1.5 ns as the gas pressure increased to 0.6MPa. A CCD camera was used to take pictures of the discharge arc between the main electrodes. As the gas pressre is ∼0.1Mpa, only one single discharge channel was observed. While the gas pressure is above 0.5Mpa, the switch usually breaks down in multi-channel mode, which would result in a low switch inductance and a faster risetime of the output voltage.

关键词： Switches Educational institutions Discharges (electric) Voltage measurement Switching circuits Electrical engineering Generators

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

Evolution of the exploding titanium wire in 5-50 kPa ambient gas

Evolution of the exploding titanium wire in 5-50 kPa ambient...

引用

IEEE International Conference on Plasma Science (ICOPS)

作者： Xiaobing Zou Zhiguo Mao Xinxin Wang Weihua Jiang Department of Electrical Engineering State Key Laboratory of Control and Simulation of Power System and Generation Equipment Tsinghua University Beijing China Department of Physics and Chemistry College of Physics North China University of Technology Beijing China

Experiments of electrical wire explosions (EEW) for nano-powder production were performed on a small-scale pulsed power device, which consists of a low-inductance capacitor bank of 2-4 μF typically charged to 8-25 kV. Titanium wires, 85 mm in length and 175 μm in diameter, were installed inside a discharge chamber filled with 5-50 kPa air. The peak discharge current is about 8-20kA with a rise time of 6 μs. We investigated the evolution of the exploding titanium wire with a Mach-Zehnder interferometer. From the time sequence of the interferograms, we found that two different modes of wire explosion exist, depending on the ambient gas pressure. As the gas pressure is in the range of 5-20 kPa, more than one vapor burst was observed, which we called multi-burst mode. While the gas pressure is above 40 kPa, the whole wire would explode totally within one single vapor burst, which we called one-burst mode. Based on the calculated deposition energy of the exploding wire and the gas discharge theory, we explained the relationship between the exploding modes and the ambient gas pressure.

关键词： Wires Titanium Educational institutions Discharges (electric) Physics Explosions Electrical engineering

来源：评论

学校读者我要写书评

暂无评论

Substation switching electromagnetic transient analysis using the time domain integral equation with a high order implicit scheme

Substation switching electromagnetic transient analysis usin...

引用

IEEE International Symposium on Electromagnetic Compatibility (EMC)

作者： Hongjun Xiang Sughun Chang Jun Zou Jians heng Yuan Sergey V. Shenderey State Key Laboratory of Control and Simulation of Power Systems and Generation Equipments Department of Electrical Engineering Tsinghua University Beijing China Electrical Environment Group Korea Electrotechnology Research Institute Changwon South Korea

A fast electric field integral in time domain using the uneven discretization and the implicit scheme is proposed to calculate the switching electromagnetic transient at a substation. The switching transient currents and the resultant radiated electromagnetic field are calculated. The propose d approach has the strength to model the bus system at a substation with a more complicated and realistic configuration that is difficult to simulate using the circuit-based method, because all the electromagnetic couplings within the bus system are included globally. The proposed method might be one of good candidates to predicate the EMI level at a substation.

关键词： Transient analysis Switches Time domain analysis Wires Integrated circuit modeling Conductors

来源：评论

学校读者我要写书评

暂无评论

An Energy-based Methodology for Locating the Source of Forced Oscillations in power systems

An Energy-based Methodology for Locating the Source of Force...

引用

IEEE International Conference on power System Technology

作者： Li Ying Shen Chen Liu Feng State Key Lab of Control and Simulation of Power Systems and Generation Equipment Tsinghua University Beijing China

Recently, several power grids of china came across low frequency oscillations which are difficult to explain by the traditional negative damping mechanism. Some researchers suggest that those oscillations be caused by external periodic disturbances according to the forced oscillation mechanism. It takes no doubt that the oscillation source location (means locating the disturbances) is imperative and decisive to eliminate such a kind of oscillations. This paper proposes a location methodology based on Energy Supply on Port derived from the Port-controlled Hamiltonian theory. By calculating the energy injected to the network at corresponding ports, the oscillation sources can be effectively located, even in complicated systems containing various kinds of control devices such as governors and exciters. Different from the traditional methodology based on eigen-analysis, the proposed methodology is naturally decentralized without the dependency on global measurements. Case studies on the standard 4-machine 2-area system and the IEEE-118 bus system show the effectiveness and efficiency of the proposed methodology.

关键词： Oscillation Source Location Forced Oscillation Port-controlled Hamiltonian Energy Supply on Port

来源：评论

学校读者我要写书评

暂无评论

Effects of manganese dioxide additives on the electrical characteristics of Al-doped ZnO varistors

引用

Science china(Technological Sciences) 2011年第8期54卷 2204-2208页

作者： LONG WangCheng HU Jun HE JinLiang LIU Jun ZENG Rong State Key Laboratory of Control and Simulation of Power System and Generation Equipment Department of Electrical Engineering Tsinghua University Beijing 100084 China

The effects of manganese dioxide (MnO 2 ) additives on the electrical characteristics of the Al-doped ZnO varistors are investigated. The leakage current densities of the samples decrease first and then increase again with the increase of the amount of MnO 2 additives. Correspondingly, the nonlinear coefficients of the samples keep on increasing and then decrease. In addition, the donor densities increase monotonously with the amount of the doped MnO 2 increasing. The effects of MnO 2 additives on the electrical characteristics of the samples are different from the conclusion of previous literatures. The reasons of the distinct effects are supposed to be related with the donor and interface state densities of the samples.

关键词： ZnO varistots manganese dioxide electrical characteristics low residual voltage ratio simulation

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

Synergistic utilization of coal and other energy- key to low carbon economy

引用

能源前沿 2011年第1期5卷 1-19页

作者： Weidou NI Zhen CHEN State Key Laboratory of Control and Simulation of Power System and Generation Equipment Department of Thermal EngineeringTsinghua UniversityBeijing 100084China

In china, coal is a dominant component of energy mix, and it is expected to remain as such over the next 30 to 40 years. Coal is expected to be used even more in power generation. The direct combustion of coal already has been causing severe pollution and ecological degradation, and it is quite difficult to address the need to reduce greenhouse gas (GHG) given the direct combustion of coal. Therefore, the polygeneration system based on coal gasification, which is one of the major examples of synergistic utilization of coal, is proposed. It is a comprehensive solution to meet the energy challenges china is facing. Furthermore, the synergy of fossil fuels (especially coal) with renewable energy, the synergy of different kinds of energy for energy storage, the synergy of centralized and distributed supply of different kinds of energy, and the synergy of different kinds of energy in smart energy grid (power, gas, heat, and water) are the keys to making china a low-carbon economy. Carbon dioxide (CO2) mitigation in china should begin from the coalchemical industry given their accumulated relevant experiences. The mitigation process should gradually be transformed into the 'IGCC + polygeneration + CCUS'.The objectives of this paper are to describe the synergistic utilization of coal, and to analyze the synergy of coal with other energy resources, and to propose the scientific and technological problems to achieve these synergies.

关键词： synergy clean and efficient utilization of coal coal-based polygenration CO2 mitigation energy storage

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：