检索结果-内蒙古大学图书馆

International Conference on Electric Utility Deregulation and Restructuring and power Technologies

作者： Xin Chen Zhiqian Bo Xinzhou Dong Shenxing Shi State Key Laboratory of Control and Simulation of Power System and Generation Equipments Tsinghua University Beijing China

ISBN: (纸本)9781467371070

The communication network of power system is often damaged after a disaster. To solve this problem, this paper uses ant colony algorithm to find the optimal circuitous route. simulation results show that the method is fast, which can accelerate the recovery of the communication network. Besides, this paper does some research on the dead end problem, and analyses relationship between degree of adjacency and ratio of coming to a dead end. The result shows that the efficiency of ant colony algorithm can be improved only if it tries to avoid coming to dead ends.

关键词： ant colony algorithm circuitous route degree of adjacency dead end

来源：评论

学校读者我要写书评

暂无评论

Short-term prediction model of module temperature for photovoltaic power forcasting based on support vector machine

Short-term prediction model of module temperature for photov...

引用

International Conference on Renewable power Generation, RPG 2015

作者： Sun, Yujing Wang, Fei Mi, Zengaiang Sun, Hongbin Liu, Chun Wang, Bo Lu, Jing Zhen, Zhao Li, Kangping State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power University Baoding Hebei Province071003 China State Key Laboratory of Control and Simulation of Power Systems and Generation Equipment Department of Electrical Engineering Tsinghua University Haidian District Beijing100084 China China Electric Power Research Institute Haidian District Beijing100192 China

ISBN: (纸本)9781785610400

To improve the prediction accuracy of photovoltaic (PV) power generation, the temperature of PV modules and its prediction is very important. A short-term step-wise temperature prediction model for PV module based on Support Vector Machine (SVM) is proposed in this paper. Firstly, the primary impact factors of PV module temperature are determined in terms of the PV module physical characteristics and the correlation coefficient between each factor and module temperature. Secondly, two kinds of prediction models, direct and step-wise models, are built to predict module temperature respectively. For direct model, the prediction model is based on SVM using the historical data. For step-wise one, the prediction models of the primary impact factors are built at the first step and then the mapping models between module temperature and the impact factors are established. In the end, the deviations of two different kinds of prediction models are analyzed and discussed based on actual operation data. The results indicate that the stepwise prediction model has better accuracy than the direct prediction model if other things are equal.

关键词： Forecasting

来源：评论

学校读者我要写书评

暂无评论

Photovoltaic plant Operating Statuses Identification model based on support vector machine using loss quantity of electricity feature parameters

Photovoltaic plant Operating Statuses Identification model b...

引用

International Conference on Renewable power Generation, RPG 2015

作者： Li, Kangping Wang, Fei Zhen, Zhao Sun, Yujing Mi, Zengqiang Sun, Hongbin Liu, Chun Wang, Bo Lu, Jing State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power University Baoding Hebei Province071003 China State Key Laboratory of Control and Simulation of Power Systems and Generation Equipment Department of Electrical Engineering Tsinghua University Haidian District Beijing100084 China China Electric Power Research Institute Haidian District Beijing100192 China

ISBN: (纸本)9781785610400

Operating Statuses Identification (OSI) can help operators to find fault timely and minimize the loss. So it is of great significance for optimal operation of photovoltaic (PV) plants. The loss quantity of electricity (LQOE) is defined as that should have been generated but actually not, which is caused by inverter fault, PV modules fault, dust stratification or combinations of them. Firstly, mathematical models of PV cells are proposed to figure out the LQOE of each PV module. Secondly, after analysing the relation between LQOE and operating statuses, an index set of LQOE describing the distinction of different operating statuses are defined including four statistical feature parameters and a user-defined index. Thirdly, Support Vector Classification models for OSI (OSI-SVC) are built with input features extracted from the index set. Lastly, simulations are carried out to verify the effectiveness and evaluate the performance of the OSI-SVC models. The results indicated that the operating statuses can be effectively recognized by the proposed model.

关键词： Support vector machines

来源：评论

学校读者我要写书评

暂无评论

Cloud identification model for sky images based on Otsu

Cloud identification model for sky images based on Otsu

引用

International Conference on Renewable power Generation, RPG 2015

作者： Li, Hongping Wang, Fei Ren, Hui Sun, Hongbin Liu, Chun Wang, Bo Lu, Jing Zhen, Zhao State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power University Baoding Hebei Province071003 China State Key Laboratory of Control and Simulation of Power Systems and Generation Equipment Department of Electrical Engineering Tsinghua University Haidian District Beijing100084 China China Electric Power Research Institute Haidian District Beijing100192 China

ISBN: (纸本)9781785610400

Irradiance changes caused by clouds movement are the mam factors, which lead to mutation of photovoltaic power. In order to increase the accuracy of the ultra-short-term photovoltaic power prediction, based on of clouds images, the cloud identification for sky images is one of the primary aspects for improving photovoltaic power accuracy. A cloud identification model for sky images is established based on Otsu. Firstly, a series of sky images are collected by Total Sky Imager (TSI) with the regions of clouds and sky are distinguished. Secondly, the color features (based on RGB values) of pixels in sample images and the spectral and texture features of the whole image are extracted;Finally, we established a cloud identification model for sky images based on Otsu according to the clouds' and sky areas' division and the general characteristics featured by pixels and images. The simulated results show that the model in this paper can identify the clouds in a sky images effectively.

关键词： Pixels

来源：评论

学校读者我要写书评

暂无评论

Wind Turbine Fault Diagnosis system Based on A Fuzzy Expert system

Wind Turbine Fault Diagnosis System Based on A Fuzzy Expert ...

引用

2015 International power,Electronics and Materials Engineering Conference(IPEMEC 2015)

作者： Wenguang Yang Dongxiang Jiang State Key Laboratory of Control and Simulation of Power System and Generation Equipments Department of Thermal EngineeringTsinghua University

ISBN: (纸本)9781510806474

A fuzzy expert system which can simultaneously support many kinds of rules including fuzzy production rule,fault tree and decision tree in a unified framework are *** rete algorithm is adopted to speed up the fuzzy reasoning chain.A wind turbine diagnosis expert system is developed based on the fuzzy expert *** data is employed to verify the feasibility of the inference engine,and the results show that with proper knowledge imported the misdiagnosis rate is low,the inference process can be exported and the match degree of the health rule can be used as a health state indicator.

关键词： Wind turbine Fault diagnosis system Fuzzy expert system Fuzzy Rete algorithm

来源：评论

学校读者我要写书评

暂无评论

Dynamic Response of Rubbing Happening in a Flexible Rotor-Bearing system

Dynamic Response of Rubbing Happening in a Flexible Rotor-Be...

引用

2015 International Conference on Electrical, Automation and Mechanical Engineering(EAME 2015)

作者： J.M.Chen D.X.Jiang T.T.Deng J.S.Wang J.L.Zhong S.B.Wang State Key Laboratory of Control and Simulation of Power System and Generation Equipments Department of Thermal Engineering Tsinghua University Guizhou Electric Power Research Institute

ISBN: (纸本)9781510806528

To reduce the steam loss and raise the efficiency of the steam turbine,the vapour seals are applied in the inner cylinder of the steam *** small gap may easily results in the rubbing happening in the inner ***,the rotor is a flexible *** this paper,dynamic response of rubbing happening in a flexible rotor-bearing system was studied.A simplified flexible rotor-bearing system was constructed,whose rotating speed was between the 1st and 2nd critical rotating *** effect was considered in the analysis,*** rubbing introduce heat and result in the thermally induced *** transient thermal bow was treated as a pair of moments functioning on the shaft segment where rubbing *** shows the amplitude and phase of vibration would be stable after a long *** severity of rubbing affect the stabilization time,which could be regarded as a diagnostic feature to identify the severity of rub happening in a flexible rotor-bearing system.

关键词： thermally induced vibration equivalent thermal moment stabilization time rubbing flexible rotor-bearing system

来源：评论

学校读者我要写书评

暂无评论

Ambient signal based load model parameter identification using optimization method

Ambient signal based load model parameter identification usi...

引用

IEEE General Meeting power& Energy Society

作者： Xinran Zhang Chao Lu Yingduo Han Songtai Yu Jifeng Wang He Huang Yinsheng Su State Key Laboratory of Control and Simulation of Power System and Generation Equipments Tsinghua University Beijing China China Southern Power Grid Guangzhou China

Load modelling is a crucial part in modelling a power system. The complex, nonlinear and stochastic characteristics of power load increase the difficulty of modelling. In this paper, a new approach of ambient signal based load model parameter identification method is proposed to solve this problem. With the proposed method, load model parameter can be identified in any time regardless of the existence of fault. First, Z+M model is simplified to reduce the number of parameters to be identified. Then, parameters of Z+M model are identified with an optimization method, the objective function of which is calculated from WAMS measured power and voltage data. An iterative process is proposed to solve the problem of initial value sensitivity in optimization problems. Finally, the effectiveness of this identification method is validated through the simulation results on WSCC three machines nine nodes system under different operation situation including both small disturbance and large disturbance.

关键词： Load modeling Optimization Integrated circuit modeling Parameter estimation Data models Reactive power power measurement

来源：评论

学校读者我要写书评

暂无评论

Natural Frequency and Dynamic Response of Rotor system of Steam Turbine Modelled with Euler-Bernoulli Beam

Natural Frequency and Dynamic Response of Rotor System of St...

引用

2015 International power,Electronics and Materials Engineering Conference(IPEMEC 2015)

作者： T.T.Deng J.S.Wang X.J.Li J.L.Zhong S.B.Wang S.P.An W.G.Yang D.X.Jiang Guizhou Electric Power Test and Research Institute State Key Laboratory of Control and Simulation of Power System and Generation Equipments Department of Thermal EngineeringTsinghua University

ISBN: (纸本)9781510806474

Based on Finite element method(FEM),analysis of natural frequency and dynamics response is carried out in this ***,modeling of rotor system in steam turbines is analyzed with Euler-Bernoulli beam ***,natural frequency of the rotor system is obtained and ***,dynamic response of the rotor system is simulated and the vibration of the rotor system is *** results show that the proposed model can obtain results with high accuracy,and the model is *** modeling approach presented in this work provides a fast and accurate method in analyzing dynamic characteristics of the practical rotor system in steam turbine units

关键词： Natural frequency transient response rotor system steam turbine Euler-Bernoulli Beam

来源：评论

学校读者我要写书评

暂无评论

A real-time wind power control method for power systems with high wind power penetration and its implementation

引用

Dianli Xitong Zidonghua/Automation of Electric power systems 2015年第21期39卷 23-29页

作者： Wang, Bin Sun, Yong Wu, Wenchuan Zheng, Taiyi Zhang, Boming State Key Laboratory of Control and Simulation of Power System and Generation Equipments Tsinghua University Beijing100084 China Department of Electrical Engineering Tsinghua University Beijing100084 China State Grid Jilin Electric Power Supply Company Changchun130021 China

A real-time wind power control method is proposed to accommodate the severe fluctuation of wind power, which can be used in power systems with high wind power penetration. The maximum allowable wind power generation is estimated online according to the automatic generation control (AGC) downward spinning reserve and the tie-line power deviation. Considering the different priorities for wind farms and the transmission security constraints, different control strategies, such as corrective control to eliminate the transmission congestion, optimal dispatch considering the trade-off between minimum curtailment of wind power and the fairness among wind farms, are integrated in the proposed method. The numerical simulation on the test system and the results of field operation in a provincial power grid show that the method is efficient and practical. © 2015 Automation of Electric power systems Press.

关键词： Wind farm

来源：评论

学校读者我要写书评

暂无评论

Automatic voltage control of wind farms based on model predictive control theory

引用

Dianli Xitong Zidonghua/Automation of Electric power systems 2015年第7期39卷 59-67页

作者： Xu, Fengda Guo, Qinglai Sun, Hongbin Lan, Haibo Liu, Haitao Liu, Xiaomin Department of Electrical Engineering Tsinghua University Beijing100084 China State Key Laboratory of Control and Simulation of Power System and Generation Equipments Tsinghua University Beijing100084 China State Grid North Hebei Grid Company Limited Beijing100053 China

Voltage fluctuations occur frequently in wind farms as a result of wind power perturbation, while reactive power control of various devices is always uncoordinated and often has a time lag when the system operates in the traditional control mode that only uses the current data for decision-making. In this case, a method for coordinated control of the reactive power of wind turbine generators (WTGs) and static var generators is proposed based on model predictive control (MPC). Unlike the traditional voltage control method, the control method proposed has the realization of optimization of the voltage control curve and the dynamic process of reactive power regulation in the future window of time as its objective. An auto regression moving average (ARMA) model is used to predict the active power of WTGs while the reactive power of WTGs and the SVG is forecasted using a first-order inertia link and a proportional integral (PI) link, respectively. Voltages in the wind farm are solved with the help of a sensitivity matrix. Thus an optimization model is developed for both the minimization of PCC voltage deviation and the maximization of SVG reactive power reservation in a future window of time. The optimizing model is solved using CPLEX tools with the dual simplex algorithm. In order to test the performance of the MPC controller, multiple cases with different wind circumstances are simulated on a DIgSILENT platform. simulation results reveal that by predicting the states of various instruments in wind farms during a period of time in the future, the proposed control method is able to rationally arrange fast/slow reactive power to respond to predictable changes of the system in advance and keep voltage stable. ©2015 State Grid Electric power Research Institute Press

关键词： Reactive power

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：