检索结果-内蒙古大学图书馆

Time-varying loads in electric power systems: Power input, equivalent circuit elements, and disturbances

EUROPEAN TRANSACTIONS ON electrical POWER 1997年第1期7卷 5-11页

作者： Knoop, M Kohle, S [?]Michael K. F. Knoop(1965)received a Dipl.-Ing. degree in electrical engineering from Universit?t Knrlsmhe. Germany. and a Dr.-hg. degree from Universit?t der Bundeswehr Hamburg Germany. He now works with the automation department of Betriebs for schungsinstitut (BFI) mainly in the tield of modelling and control of electric xc furnaces. His interests also include dynamic systems and control theory. (Betriebsforschungsinstitut. VDEh-lnstitut fur angewandte Forschung GmbH. Postfach I05 145. D-40042 Dusseldorf Tel+491 I1/6707-385 Fax +49211/6707-3 10)

Time-varying electric loads, fluctuating around their nominal point, cause fluctuations also of current and power. The mean phasors of current and complex power differ from their nominal values, which results in a deflection of mean power input. A transformation to a time-invariant equivalent circuit is introduced representing the mean values of voltage, current and power. The variances on the other hand contribute equations for a second phenomenon of fluctuating lends: the generation of disturbances in the power supply system. Results for both phenomena are derived for single-phase lends, validated by Monte-Carlo simulations, and generalized to three important kinds of three-phase bonds. Measured data from an electric arc furnace illustrate the application of ideas.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Predictive gain scheduling autopilot for ships

Predictive gain scheduling autopilot for ships

引用

Mediterranean Electrotechnical Conference (MELECON)

作者： Z. Vukic L. Kuljaca D. Milinovic Department of Control Engineering and Computer Engineering in Automation Faculty of Electrical Engineering and Computing University of Zagreb Zagreb Croatia

The paper presents results of research with the new predictive autopilot structure (PIP+D) with gain scheduling. The autopilot is tested and compared with conventional PID autopilot for a mariner class ship. The autopilot parameters are changed with the speed of the ship using the gain scheduling technique. Results obtained during the research show that the proposed autopilot structure is to be recommended if improved performance is of prime interest, when the velocity of the ship is changing. The analysis is based on the simulation of a mariner class ship as a nonlinear system, with the steering servo system taken as a nonlinear model. Results of the simulation are included.

关键词： Marine vehicles Limit-cycles Gears Servomechanisms System testing Spirals Mathematical model Performance gain Regulators

来源：评论

学校读者我要写书评

暂无评论

Application and comparison of alternative position sensors in high-accuracy control of an X-Y table

Application and comparison of alternative position sensors i...

引用

International Workshop on Advanced Motion control (AMC)

作者： M. Fischer M. Tomizuka Institute of Automatic Control Laboratory of Control Systems and Process Automation Technical University of Darmstadt Darmstadt Germany Department of Mechanical Engineering University of California Berkeley Berkeley CA USA

High-accuracy positioning is applied in a variety of modern computer-controlled machines. The achievable precision is not only determined by the mechanical properties of the systems but strongly depends on the utilized control algorithms and the quality of the sensor signals. The objective of this paper is to demonstrate how alternative position sensors influence the performance of a robust digital tracking controller consisting of a disturbance observer in the velocity loop, a feedback controller in the position loop, and a zero phase error tracking controller as feedforward controller. Two different sensor systems for an x-y positioning table are considered. While a digital encoder is attached to the actuating motor, a laser interferometer with a significantly higher resolution directly measures the position of the compliantly coupled table. The latter case represents a noncollocated system. After introducing the hardware setup, both the system identification and the controller design are briefly reviewed. The impact of the measurement device on the control performance and the optimal choice of the controller parameters are investigated in extensive experiments.

关键词： Mechanical sensors Velocity control control systems Sensor systems Tracking loops Optimal control Application software Mechanical factors Robust control Digital control

来源：评论

学校读者我要写书评

暂无评论

CONDITIONS ON SOURCE SIGNALS FOR BLIND SEPARATION

CONDITIONS ON SOURCE SIGNALS FOR BLIND SEPARATION

引用

1996 3rd International Conference on Signal processing(ICSP’96)

作者： Jie Zhu Xi-Ren Cao Institute of Radio & Automation Control The South China University of Technology Department of Electrical & Electronic Engineering The Hong Kong University of Science and Technology

ISBN: (纸本)0780329120

In blind source separation problem it is usually assumed that the source signals are mutually *** has been realized that this assumption is not *** this paper,we provide some general conditions under which the source signals can be recovered from their linear mixtures. We first define two concepts,the mutually M-th order independence and the pairwise M-th order independence,on a set of random *** we prove that if the source signals are mutually M-th order independent,then those source signals,each of which has at least one nonzero m-th order cumulant for 3≤m≤M,can be *** conclusion is in spirit similar to but more general than that proposed by Tong et al[10].The constructive proof suggests an algorithm for the blind separation of sources which are mutually Af-th order *** examples arc presented to illustrate the results.

关键词： CONDITIONS ON SOURCE SIGNALS FOR BLIND SEPARATION

来源：评论

学校读者我要写书评

暂无评论

Extended Horizon Predictive control of Non-Linear Systems - Multi-Dimensional Optimisation and Suboptimal Solution

引用

IFAC Proceedings Volumes 1996年第8期29卷 57-62页

作者： Robert Haber Ruth Bars Department of Process Engineering Laboratory of Process Control Cologne Institute of Technology (Fachhochschule Köln) D-50679 Köln Betzdorfer Str. 2 Germany Department of Automation Technical University of Budapest H-1111 Budapest Goldmann Gy. tér 3 Hungary

Predictive control strategies have been proved effective and robust in practice. These algorithms were developed mainly for linear processes. The main idea is to determine the control signal minimising the deviation between a reference signal and the predicted process output in a given prediction horizon. A simplified version is one-step-ahead predictive control, where prediction horizon is restricted to one future point. Extended horizon control proposed by Ydstie (1984) is enlengthened one-step-ahead control which lets more time for the settling process than the dead time. Extended horizon predictive control strategy is derived here for a class of nonlinear systems. Some simulation results show the effect of the tuning parameters for the reference signal tracking performance of the nonlinear system.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Sliding mode control of multiple modular DC-to-DC power converters

Sliding mode control of multiple modular DC-to-DC power conv...

引用

IEEE Conference on control Technology and Applications (CCTA)

作者： Y.B. Shtessel O.A. Raznopolov L.A. Ozerov Department of Electrical and Computer Engineering University of Alabama Huntsville Huntsville AL USA Department of Automation and Remote Control Chelyabinsk Technical University Chelyabinsk Russia

Autonomous systems of electric power supply consisted of one common primary source of electric power supply and a set of multiple modular switched-controlled secondary sources of electric power supply (DC-to-DC power converters) are considered. The interconnection of the processes in secondary sources through the common primary source increases the dimension of the switched-control problem and leads to extra nonlinear (bilinear) effects. The problem of the stabilization of the voltage transformed by the multiple modular switched-controlled secondary sources of electric supply is formulated and solved in sliding modes. The robust decoupled linear desired behavior of the stabilization errors of the transformed voltage is guaranteed in local sliding modes. In order not to overload some of the basic DC-to-DC power converters within each multiple modular secondary source of electric power supply the differences between the currents consumed by these basic converters are set to zero in sliding modes.

关键词： Sliding mode control DC-DC power converters Power supplies Switching converters Batteries Automatic control Robust control Voltage control Matrix converters Power system interconnection

来源：评论

学校读者我要写书评

暂无评论

Improved inference for Takagi-Sugeno models

Improved inference for Takagi-Sugeno models

引用

IEEE International Conference on Fuzzy Systems (FUZZ-IEEE)

作者： R. Babuska C. Fantuzzi U. Kaymak H.B. Verbruggen Department of Electrical Engineering Control Laboratoiy Delft University of Technnology Delft Netherlands Laboratory of Automation and Robotics University of Bologna-DEIS Bologna Italy

Some undesirable properties of the standard Takagi-Sugeno (TS) inference method are discussed in relation to an analysis of the TS model and its approximation accuracy. A new inference method based on a smoothing maximum function is proposed. This method guarantees smoothness of the model output to a desired degree, boundedness of the output gradient at each point by the local gradients of the rule consequences and also improves the accuracy of the TS model, as demonstrated in the given numerical examples.

关键词： Takagi-Sugeno model Fuzzy sets Interpolation Vectors Artificial intelligence

来源：评论

学校读者我要写书评

暂无评论

FPGA-based implementation of Synchronous Petri Nets

FPGA-based implementation of Synchronous Petri Nets

引用

International Conference on Industrial Electronics, control and Instrumentation

作者： Naehyuck Chang Wook Hyun Kwon Jaehyun Park Control Information Systems Laboratory School of Electrical Engineering Seoul National University Seoul Department of Industrial Automation Engr Inha University Ichon South Korea

ISBN: (纸本)0780327756

This paper describes a flexible and systematic implementation method of Petri Nets that can be applied to high speed parallel control. This paper suggests a hard-wired implementation for a high frequency clock-driven system with little jitter. To implement Petri Nets with synchronous (clock-driven) digital circuits, a Synchronous Petri Net is proposed. The suggested implementation method is based on a regular cell-array such as FPGA (field programmable gate array). Radix-k Petri Net and Radix-k conversion are defined to solve technology mapping problem of FPGA that consists of k-size cells. Cell usage, cell utilization, cell complexity, and speed index are defined and derived, which are used for quantitative analysis and efficient design. To help the design process, necessary CAD tools such as design entry library, hard-macro library, and net-list converter are developed. The suggested method is demonstrated using Xilinx FPGA, and its operation is verified by computer simulations.

关键词： Petri nets Field programmable gate arrays Clocks Libraries control systems Frequency Jitter Digital circuits process design Design automation

来源：评论

学校读者我要写书评

暂无评论

Fast genetic on-line learning algorithm for neural network and its application to temperature control

Fast genetic on-line learning algorithm for neural network a...

引用

IEEE International Conference on Evolutionary Computation

作者： A.V. Topalov Kwang-Choon Kim Jong-Hwan Kim Bong-Kuk Lee Control Systems Department Technical University Sofia Plovdiv Plovdiv Bulgaria Department of Electrical Engineering KAIST Daejeon South Korea Process Control Laboratory LG Industrial Systems Research and Development Center Anyang South Korea

The paper proposes a fast online learning method for neural network structures by using genetic algorithm (GA) and dynamic back propagation algorithm (BP) jointly. GA is used in the coarse tuning process which adjusts interconnection weights of the neural network. The dynamic back propagation algorithm is subsequently applied to achieve fine adjusting of the network weights. The fitness function, based on the squared error between the teaching signal and the network output value, is redefined at every time step and the proposed GA based algorithm solves a nonstationary function optimization task. At every time step the solution with the best fitness function is used for current representation of the neural network weights and biases. It is shown through the simulations and real time temperature control of drying oven that this learning algorithm has faster convergence ability and better performance on reducing mapping error in the online learning neural network structures. This leads to an improvement of the transient response of neuro adaptive systems. The proposed method has the potential to be applied to many practical areas such as system modeling and control, signal processing and pattern recognition.

关键词： Neural networks Signal processing algorithms Heuristic algorithms Learning systems Genetic algorithms Education Temperature control Ovens Error correction Transient response

来源：评论

学校读者我要写书评

暂无评论

Application of fuzzy logic technology for spatial load forecasting

Application of fuzzy logic technology for spatial load forec...

引用

IEEE PES Transmission and Distribution Conference and Exposition

作者： Mo-yuen Chow Hahn Tram Department of Electrical and Computer Engineering North Carolina State University Raleigh NC USA Systems Control-Distribution Automation ABB Power Transmission and Distribution Company Inc. Cary NC USA

ISBN: (纸本)0780335228

Utilities are required to provide reliable power to customers. In the design stages, utilities need to plan ahead for anticipated future load growth under different possible scenarios. Their decisions and designs can affect the gain or loss of millions of dollars for their companies as well as customer satisfaction and future economic growth in their territory. This paper proposes and describes the general methodology to use fuzzy logic to fuse the available information for spatial load forecasting. The proposed scheme can provide distribution planners other alternatives to aggregate their information for spatial load forecasting.

关键词： Fuzzy logic Load forecasting Power system reliability Costs Power system planning Geographic Information Systems Economic forecasting Distributed computing Customer satisfaction Power generation economics

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：