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ifac symposium on power Plants and power systems control, PP and PSC 2009

作者： Hubka, Lukas Technical University of Liberec Faculty of Mechatronics Informatics and Interdisciplinary Studies Institute of System Control and Reliability Management Czech Republic

This paper presents a nonlinear state space model for thermal process of steam reheating. The purpose of the model is to examine existing control system and to support the development of new more efficient control systems for steam reheating units. This model describes countercurrent heat exchanger (biflux) with bypass and two parallel flow heat exchangers with bypasses and spray attemperator. The model includes interconnections of subsystems and the dynamics of all control valves. The model is a state model which enables modeling of power variation from start up to shut down. First, the basic principles of this approach are compared with already published results. Second, the model is calibrated for the newly designed reheating unit for the planned upgrade of a power plant. Both results from static and dynamic characteristic responses, as well as selected control responses in operating range are presented.

关键词： Steam

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Rate bounded linear parameter varying control of a wind turbine in full load operation

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ifac Proceedings Volumes 2008年第2期41卷 5593-5598页

作者： Kasper Zinck Østergaard Jakob Stoustrup Per Brath Turbine Control and Operation R&D Vestas Wind Systems Automation and Control Department of Electronic Systems Aalborg University

This paper considers the control of wind turbines using an LPV design technique. The controller design is done by a combination of a method that uses elimination of controller variables and a method using a congruent transformation followed by a change of variables. An investigation is performed to understand the gap between zero rate of variation and arbitrary fast rate of variation for the selected scheduling variable. In particular it is analysed for which rate of variation, the local performance level starts to deteriorate from the performance level that can be obtained locally by LTI controllers. A rate of variation is selected which is expected only to be exceeded outside the normal wind turbine operating conditions. For this rate of variation a controller has been designed and simulations show a performance level over the operating region which is very similar to what can be obtained by LTI designs for the specific operating condition. The LPV controller, however, works for the whole operating range with reasonably fast changes within this.

关键词： gain scheduling linear parameter varying (LPV) systems modelling operation and control of power systems Output feedback control LMIs Industrial applications of optimal control

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A Continuous Time Analog-to-Digital Converter With 90μW and 1.8μV/LSB Based on Differential Ring Oscillator Structures

A Continuous Time Analog-to-Digital Converter With 90μW and...

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IEEE International symposium on Circuits and systems (ISCAS)

作者： Andreas Tritschler Corporate Sector Research and Advance Engineering Gerlingen Germany

A low-power, high-resolution analog-to-digital converter (ADC) for sensor applications is presented in this paper. Its principle emanates from the popular slope techniques by replacing the voltage controlled current source with a voltage controlled oscillator (VCO). The analog input voltage modulates the oscillator frequency, which is integrated continuously and quantised using delay elements of a ring oscillator. The resulting phase information represents the moving average (MA) of the input voltage during the integration interval. The use of a continuously operating and integrating VCO eliminates the need for a separate sample and hold stage. Due to the averaging process, pre-filtering in order to prevent anti-aliasing and to perform noise reduction is often unnecessary. To the author's knowledge (Watanabe et al., 2003), (Watanabe et al., 2003) represent the only published realisations of the principle. Both papers use inverter-based ring oscillators which are inherently nonlinear and need a synchronisation circuitry to ensure oscillation. The linearity of the converter is determined by the linearity of the VCO transfer characteristic. Differential structures recommended in this paper greatly improve the overall linearity and lead to a low-power converter design. Thorough insights of the performance-limiting phenomena are obtained by utilisation of sophisticated modelling techniques from related fields of research. The provided tools enable designers to meet stringent specifications with respect to power consumption, resolution and linearity.

关键词： Analog-digital conversion Ring oscillators Voltage-controlled oscillators Linearity Voltage control Frequency modulation Delay Noise reduction Frequency synchronization Circuits

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Iterative ECG signal filtering for better malfunction recognition and diagnosis 5

Iterative ECG signal filtering for better malfunction recogn...

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5th ifac symposium on modelling and control in Biomedical systems

作者： Szilágyi, SM Benyó, Z Dávid, L Faculty of Technical and Human Science Sapientia Hungarian Science University of Transylvania Hungary Department of Control Engineering and Information Technology Budapest University of Technology and Economics Hungary

ISBN: (纸本)0080441599

This paper presents an adaptive, iteratively functioning ECG signal filtering method. After a conventional pre-filtering, the waves from the signal are localized and the model's parameters are determined. The gained information allows an iterative-type filtering in permanent concordance with the aimed processing manner. The structure of the algorithm allows real-time adaptation to the heart's state. Using these methods for one channel of the MIT-BIH database, the detection rate of QRS complexes is above 99.8%. The negative influence of various noise types, like 50/60 Hz power line, abrupt baseline shift or drift, and low sampling rate was almost completely eliminated. ifac.

关键词： medical applications real-time systems neural network signal processing spectrum analysis iterative methods regression algorithm systems

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OPTIMIZATION modelling AND SIMULATION FOR PRODUCTION PLANNING IN FLEXIBLE MANUFACTURING SYSTEM

OPTIMIZATION MODELLING AND SIMULATION FOR PRODUCTION PLANNIN...

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6th ifac symposium on Large Scale systems - Theory and applications 1992

作者： KALACHEV, VN KRIVONOZKO, VE NEMCHINOV, BV INT RES INST MANAGEMENT SCI MOSCOW 117312RUSSIA

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CONTINUOUS-TIME ADAPTIVE-control OF CONSUMER ELECTRONIC-CIRCUITS

CONTINUOUS-TIME ADAPTIVE-CONTROL OF CONSUMER ELECTRONIC-CIRC...

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4TH ifac symposium on Adaptive systems in control and Signal Processing 1992

作者： ALBERTI, EB UNIV POLITECH CATALUNYA DEPT SIGNAL THEORY & COMMUNE-08080 BARCELONASPAIN

ISBN: (纸本)0080417175

Adaptive systems have been exported to electronic applications, especially to telecommunications circuitry. The exported theory is mainly based on recursive or iterative methods. Continuous-time adaptive systems have been scarcely used for Electronic Design, especially for Consumer Electronics, a field with a primary industrial interest. At present, much theory has been developed and many problems related with the application of this theory have been studied: this makes possible to export their results to industrial consumer electronics field with full confidence. After a revision of the state-of-the-art, three well-known electronic circuits (audio power amplifiers) with different complexity are selected and analyzed in order to experiment applications of adaptive systems. Both Lyapunov and Hyperstability based theories (from reduced order models) are studied and an alternative to the classical electronic design is proposed. The performances of different adaptive structures are experimentally evaluated. Finally, some conclusions obtained either from physical implementation of the chosen adaptive systems or from the interpretation of experimental results are presented.

关键词： control applications AMPLIFIERS MODEL REFERENCE control NONLINEAR systems ROBUST control

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INTEGRATION OF TRANSFORMERS WITH VOLTAGE REGULATION INTO AN OPTIMAL power-FLOW ALGORITHM FOR THE VEW HV AND EHV GRID

INTEGRATION OF TRANSFORMERS WITH VOLTAGE REGULATION INTO AN ...

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ifac symposium on control of power Plants and power systems

作者： STELZNER, P HAUBRICH, HJ HEINZ, D VEREINIGTE ELEKTRIZITATSWERKE WESTFALEN AG W-4600 DORTMUND 1GERMANY

ISBN: (纸本)0080417094

When introducing an Optimal power Flow algorithm in the control centre of the German utility VEW it had to be considered that all transformers feeding the 110 kV voltage level are equipped with local voltage regulators. The paper deals with the modelling of those decentralized voltage regulators and their integration into an existing optimal power flow algorithm developed at the Aachen University of Technology. The main results achieved by application of the extended Optimal power Flow algorithm to the VEW HV and EHV grid are presented.

关键词： OPTIMAL power FLOW (OPF) QUADRATIC PROGRAMMING OPTIMIZATION OBSERVABILITY ONLINE OPERATION VOLTAGE control power SYSTEM control

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INTRODUCTION OF EXPERT-systems AND FUZZY-LOGIC INTO THE OPERATION ENVIRONMENT OF power-PLANTS AND power-systems (SURVEY)

INTRODUCTION OF EXPERT-SYSTEMS AND FUZZY-LOGIC INTO THE OPER...

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ifac symposium on control of power Plants and power systems

作者： VANSON, PJM ECC EUROPE MAASTRICHTNETHERLANDS

ISBN: (纸本)0080417094

Artificial Intelligence, in particular Expert systems (ES) and Fuzzy Logic Reasoning is often referred to as the `new revolution' in many industrial applications. The introduction of this new technology into the operation environment of power Plants and power systems demands special attention. The `new revolution' should of course, not end in a new deception in the area of the end users but should really offer them reliable and appropriate tools to improve their effectiveness. This paper shortly outlines the aim and the organization of the discussion on the practical side of ES and Fuzzy Logic at the Round Table Discussion.

关键词： OPERATION OF power PLANTS, OPERATION OF power systems, EXPERT systems, FUZZY LOGIC REASONING

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STATE ESTIMATION IN THERMAL power-STATIONS

STATE ESTIMATION IN THERMAL POWER-STATIONS

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ifac symposium on control of power Plants and power systems

作者： STREIT, S WEINER STADTWERKE RECHENZENTRUMA-1095 VIENNAAUSTRIA

ISBN: (纸本)0080417094

When performing technical measurements the measured values deviate from the true values. These deviations are caused by unavoidable random errors as temporal disturbances, environmental interferences etc., and by not measurable systematic errors, as errors in sensors, errors in their installation, errors in sampling etc., which can also be taken for random errors. Thus the measured values represent single values of random variables. Therefore the characteristic factors calculated from the measured values are also single values of random variables. That means the calculated characteristic factors deviate stochastically from the true characteristic factors of the thermal power station. For a correct assessment these stochastic deviations must be taken into account. Therefore the mean square deviations of the characteristic factors must be calculated by means of the calculus of error from the variances of the measured variables. It is evident, that a correct assessment can be the more accurate, the smaller the mean square deviations of the characteristic factors are. Furtheron a computer aided method, based on the least square method, for the evaluation of measurements in thermal power stations will be presented. The basic idea of this method is to gather all available measured values together with their variances and to set up auxiliary conditions with them, which must be met by the true values. These auxiliary conditions are simple laws of physics, as the law of conservation of mass, conservation of energy, etc., or simple laws of chemistry, as for instance stoichiometry. The measured values will not fulfill these auxiliary conditions, but will lead to contradictions caused by the unavoidable stochastic errors. Out of these contradiction can be obtained on the one hand a general assessment of the credibility of the measured values and on the other hand selective clues of grave errors in measurement. Furthermore the estimated values produced by this method from the me

关键词： STATE ESTIMATION LEAST-SQUARES ESTIMATION COMPUTER applications FAILURE DETECTION PARAMETER ESTIMATION THERMAL PLANTS STEAM GENERATORS STEAM TURBINES ACCEPTANCE TESTS

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power systems modelling and control applications - selected papers from the ifac symposium

Power Systems Modelling and Control Applications - Selected ...

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power systems modelling and control applications - selected papers from the ifac symposium

The symposium proceedings contains 72 paper that are grouped according to the following subjects: voltage control, data administration, data exchange, stability, modeling of generating plant, security analysis and monitoring, power system modeling, emergency, restoration, planning and operating tools, power plant control, power system control, economic optimization, expert systems, state estimation, and training simulators. Topics covered include: turbogenerators, robustness, observability, hierarchical systems, substations, knowledge bases, power distribution, load dispatching, power flow analysis, gas turbines, control valves, steam turbines, solar power plants, nuclear plants, data transmission, matrix algebra, algorithms, and boiler systems.

关键词： Electric power systems

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