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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

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Probabilistic production simulation of a power system with wind power penetration based on improved UGF techniques

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Journal of Modern power systems and Clean Energy 2013年第2期1卷 186-194页

作者： Hongtao WANG Xu LIU Chunyi WANG Key Laboratory of Power System Intelligent Dispatch and Control of Ministry of Education Shandong UniversityJinan 250061China State Grid Zhejiang Electric Power Company Jiaxing Power Supply CompanyJiaxing 314001China State Grid Shandong Electric Power Company Jinan 250001China

Universal Generating Function(UGF)techniques have been applied to Multi-state system(MSS)reliability analysis,such as long term reserve expansion of power systems with high wind power ***,using simple steady-state distribution models for wind power and large generating units in reliability assessment can yield pessimistic *** more accurately assess the power system reliability,UGF techniques are extended to dynamic probabilistic simulation analysis on two aspects of modelling ***,a principal component analysis(PCA)combined with a hierarchal clustering algorithm is used to achieve the salient and time-varying patterns of wind power,then a sequential UGF equivalent model of wind power output is established by an apportioning ***,other than the traditional two-state models,the conventional generator UGF equivalent model is established as a four discrete-state continuous-time Markov model by *** the construction process of such a UGF model,the state values are transformed into the integral multiples of one common factor by choosing proper common factors,thus effectively restraining the exponential growth of its state number and alleviating the explosion *** method is suitable for reliability assessment with dynamic probabilistic distributed random *** addition,by acquiring the clustering information of wind power,the system reliability indices,such as fuel cost and CO_(2) emissions through different seasons and on different workdays,are ***,the effectiveness of the method is verified by a modified IEEE-RTS 79 system integrated with several wind farms of historical hourly wind power data of Zhangbei wind farm in North China.

关键词： Multi-state system Reliability Universal Generating Function(UGF) Probabilistic production simulation Wind power

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Finite-time stability and stabilization of It stochastic time-varying systems

Finite-time stability and stabilization of It stochastic t...

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第三十三届中国控制会议

作者： YAN Zhiguo ZHANG Weihai LIN Zhongwei School of Electrical Engineering and Automation Qilu University of Technology College of Electrical Engineering and Automation Shandong University of Science and Technology State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources School of Control and Computer EngineeringNorth China Electric Power University

This paper deals with the finite-time stability and stabilization for continuous-time linear stochastic time-varying systems. Several necessary and sufficient conditions and a sufficient condition for finite-time stability are derived. Moreover,a sufficient condition for the existence of state feedback controller is given. Such results involve the feasibility problems of differential linear matrix inequalities with terminal constraint.

关键词： Stochastic systems,time-varying systems,finite-time stability

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On Dispatching power systems with Significant Wind Generation Using Disturbance Feedbacks

On Dispatching Power Systems with Significant Wind Generatio...

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第三十二届中国控制会议

作者： WEI Wei MEI Shengwei LIU Feng State Key Laboratory of Control and Simulation of Power Systems and Generation Equipment Department of Electrical EngineeringTsinghua University

ISBN: (纸本)9781479900305

With the rapid development of renewable energies,especially wind power,how to manage unexpected generation variations economically and reliably in dispatch has become crucial for modern power *** address this issue,this paper presents an affine disturbance feedback robust dispatch(ADF-RD) methodology for power systems with large scale wind power integration in the framework of adjustable robust optimization(ARO).This methodology divides the dispatching process into pre-dispatch and ***-dispatch decision immunizes against all possible realizations of uncertainties in a set,while re-dispatch which can be regarded as a feedback will be adaptively adjusted using an affine function with respect to the realized uncertainty in real *** ADF-RD methodology is applied to an hourly ahead dispatch(HAD) *** effectiveness and efficiency of the proposed ADF-RD methodology are demonstrated by numerical experiments carried on a five-bus system.

关键词： Adjustable robust optimization affine disturbance feedback power system dispatch uncertainty wind power

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Research on platform for advanced contorl of energy storage system

Research on platform for advanced contorl of energy storage ...

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2nd IET Renewable power Generation Conference, RPG 2013

作者： Xu, Hanchen Yuan, Zhichang Lu, Chao Wang, Can Guo, Haifeng Li, Yongxing State Key Laboratory of Control and Simulation of Power System and Generation Equipments Tsinghua University Beijing 100084 China China Southern Power Grid Power Generation Company Guangzhou 510630 China

ISBN: (纸本)9781849197588

Advanced applications of energy storage system comprise load shifting, isolated island operation, frequency regulation and reactive support, etc. There are already algorithms and control strategies for advanced applications, but still lack an independent supporting software platform. This paper concentrates on the structure and realization of software platform for advanced application of large-scale energy storage system, including demand analysis, software architecture and module design, user interface and functionality development. An easy to operate and expand software platform, with a beautiful graphical user interface and support for visualization of data, was designed and implemented.

关键词： Energy storage

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Lightning overvoltage suppression to UHV power transformer by ferromagnetic ring

Lightning overvoltage suppression to UHV power transformer b...

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作者： Zhang, Xiao He, Jinliang State Key Laboratory of Control and Simulation of Power System and Generation Equipments Department of Electrical Engineering Tsinghua University Beijing 100084 China

Lightning overvoltage protection is of great importance to the safety of devices in UHV GIS. In practice, insulation failure of UHV transformer due to lightning strike is often reported. The widely used UHV metal-oxide arresters can suppress the magnitude of lightning overvoltage but lack effectiveness on alleviating the steepness. A new protection method is proposed in this paper using ferromagnetic ring as supplement to the arresters in suppressing lightning overvoltage within UHV GIS. Moreover, equivalent model based on the characteristic of ferromagnetic material and factual dimensions of the ring is established. simulation of an actual 1000 kV GIS is carried out to thoroughly evaluate the lightning overvoltage suppressing effect of ferromagnetic rings with different materials and structure parameters. © 2012 Elsevier B.V. All rights reserved.

关键词： power transformers

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control of parallel grid-connected photovoltaic inverters with common dc bus

Control of parallel grid-connected photovoltaic inverters wi...

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2nd IET Renewable power Generation Conference, RPG 2013

作者： He, F. Zhao, Z. Yuan, L. Lu, T. State Key Laboratory of Control and Simulation of Power System and Generation Equipment Department of Electrical Engineering Tsinghua University Beijing 100084 China

ISBN: (纸本)9781849197588

This paper proposes a hierarchical control scheme for parallel grid-connected PV inverters with a common dc bus. Droop control and group coordination are implemented to achieve equal power sharing between inverters as well as zero steady-state error for dc voltage regulation. The implementation is specifically designed for distributed control to promote modularization and system reliability. Experimental results have verified that the proposed scheme is effective.

关键词： Electric power transmission networks

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A sensor network modeling and fault detection method for large wind farms by using neural networks

A sensor network modeling and fault detection method for lar...

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International Conference on control and Automation (ICCA)

作者： Qing Wang Fan Yang Quanbo Ge Qinmin Yang Zhejiang Windey Co. Ltd State Key Laboratory of Wind Power System Hangzhou Zhejiang China School of Automation Hangzhou Dianzi University Hangzhou China Department of Control Science and Engineering Zhejiang University Hangzhou China

Sensor networks have been widely utilized in various applications. In large wind farms, numerous sensor nodes are deployed across the field for monitoring purpose. They are required to work in harsh environment and usually undergo unexpected failures. This paper introduces a new method to model nodes of sensor networks by using two-layer neural networks (NN). Each node's dynamics and interconnections with other sensor network nodes are integrated into the model, whose accuracy is guaranteed by the NN's universal approximation property. Furthermore, the model can be subsequently employed to detect any incipient failures which can be modeled as a nonlinear function of state and input variables. An additional NN along with a novel simplified updating law is utilized for self-diagnostics, whose output can declare a failure alarm if it exceeds a certain threshold. Mathematical analysis is substantiated with simulation results.

关键词： Conferences Automation

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Determination of the principal components for the optimal detection performance of a combined index

Determination of the principal components for the optimal de...

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第25届中国控制与决策会议

作者： Tian Qiu Xiaojing Bai Xiyu Zheng Xiang Zhu State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources School of Control and Computer Engineering North China Electric Power University

ISBN: (纸本)9781467355339

In process monitoring, faults might be completely detected by or or both of them. However, one index rather than two indices is preferred to monitor a process in practice. The number of principal components (PCs) in principal component analysis (PCA) impacts the fault detection performance obviously. In this paper, we focus on developing a selection criterion for the number of the PCs based on the best detection performance of the combined index and discussing the uncertainty of PCA model through cross validation. The simulation demonstrates that one index has a good detection performance and simplifies the detection system.

关键词： principal component analysis (PCA), fault detection, detection performance, fault amplitude

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A coordination control strategy of voltage source converter based MTDC for offshore wind farms

A coordination control strategy of voltage source converter ...

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Conference Record of the IEEE Industry Applications Society Annual Meeting (IAS)

作者： Jing-guo Ren Ke-Jun Li Lijun Sun Jian-guo Zhao Yong-liang Liang Wei-Jen Lee Zhao-hao Ding Ying Sun Key Laboratory of Power System Intelligent Dispatch Control of Ministry of Education Shandong University Jinan P.R. China Shandong Electric Power Research Institute State Grid of China Technology College Jinan P.R. China Energy Systems Research Center The University of Texas at Arlington Arlington TX USA

This paper proposes a coordination control strategy of voltage source converter based multi-terminal DC (VSC-MTDC) transmission system for integrating large-scale offshore wind power. Using a typical five-terminal DC transmission system as an example, coordination control strategy based on local controller among converter stations is proposed. Based on the DC voltage-active power characteristic, improved control strategy for auxiliary converter station and APC converter station are proposed respectively. Also the working mode of the two converter stations is analyzed. The basis of parameter selection of auxiliary converter station and APC converter station is presented due to DC power flow distribution and maximum and minimum operational mode. Finally, simulations in PSCAD/EMTDC are conducted to validate the multi-point DC voltage control method under various operating state in normal, master converter station fault and auxiliary converter station fault conditions respectively. Results show that this method can guarantee the active power allocation of VSC-MTDC transmission system and good control effects are obtained.

关键词： Voltage control power conversion Wind farms control systems power transmission Load flow

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