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Controle não linear aplicado a dispositivos FACTS em sistemas elétricos de potência; Nonlinear control applied to FACTS devices in power systems

Siqueira, Daniel Souto
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 24/04/2012 PT
Relevância na Pesquisa
65.9%
O TCSC é um dos compensadores dinâmicos mais eficazes empregados em Sistemas Elétricos de Potência, pois, oferece um ajuste flexível, de forma rápida e confiável, possibilitando a aplicação de teorias avançadas no seu controle. Estes dispositivos podem desempenhar funções importantes para a operação e o controle do sistema, trazendo inúmeros benefícios. Devido aos benefícios que o uso deste dispositivo oferece, uma grande quantidade de trabalhos vem sendo desenvolvidos com o intuito de sintetizar leis de controle para o mesmo. Porém, a maioria destes trabalhos é fundamentado em técnicas de controle clássico, isto é, projetando leis de controle baseado em sistemas linearizados e para pontos específicos da operação. Estas técnicas de análise entretanto, não garantem que para perturbações que levam o sistema para pontos distantes daqueles usados no projeto do controlador, a atuação do controlador seja eficaz e contribua assim para a estabilização do sistema. Visando o estudo mais aprofundado dos fenômenos que ocorrem nos sistemas físicos, modelos não lineares vêm sendo empregados, e as técnicas de projeto de controladores baseadas nesses modelos, são cada vez mais desenvolvidas. Neste trabalho será empregada a técnica de controle não linear baseada na Função Energia Generalizada de Controle para síntese de leis de controles estabilizantes para os dispositivos TCSC considerando...

Optimal linear and nonlinear control design for chaotic systems

Rafikov, Marat; Balthazar, José Manoel
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Conferência ou Objeto de Conferência Formato: 867-873
ENG
Relevância na Pesquisa
75.93%
In this work, the linear and nonlinear feedback control techniques for chaotic systems were been considered. The optimal nonlinear control design problem has been resolved by using Dynamic Programming that reduced this problem to a solution of the Hamilton-Jacobi-Bellman equation. In present work the linear feedback control problem has been reformulated under optimal control theory viewpoint. The formulated Theorem expresses explicitly the form of minimized functional and gives the sufficient conditions that allow using the linear feedback control for nonlinear system. The numerical simulations for the Rössler system and the Duffing oscillator are provided to show the effectiveness of this method. Copyright © 2005 by ASME.

Phase Space Navigator: Towards Automating Control Synthesis in Phase Spaces for Nonlinear Control Systems

Zhao, Feng
Fonte: MIT - Massachusetts Institute of Technology Publicador: MIT - Massachusetts Institute of Technology
Formato: 31 p.; 4810612 bytes; 3851493 bytes; application/postscript; application/pdf
EN_US
Relevância na Pesquisa
75.85%
We develop a novel autonomous control synthesis strategy called Phase Space Navigator for the automatic synthesis of nonlinear control systems. The Phase Space Navigator generates global control laws by synthesizing flow shapes of dynamical systems and planning and navigating system trajectories in the phase spaces. Parsing phase spaces into trajectory flow pipes provide a way to efficiently reason about the phase space structures and search for global control paths. The strategy is particularly suitable for synthesizing high-performance control systems that do not lend themselves to traditional design and analysis techniques.

Discrete Verification of Necessary Conditions for Switched Nonlinear Optimal Control Systems, ACA (2004; Boston, Massachusetts)

Ross, I. Michael; Fahroo, Fariba
Fonte: IEEE Publicador: IEEE
Tipo: Conference Paper
Relevância na Pesquisa
75.88%
The article of record as published may be located at http://ieeexplore.ieee.org; Approved for public display, distribution unlimited; Proceeding of the 2004 American Control Conference Boston, Massachusetts ; vol. 2, page(s):1610-1615, June 30-July 2, 2004; We consider a fairly general class of state-constrained nonlinear hybrid optimal control problems that are based on coordinatizing Sussmann's model. An event set generalizes the notion of a guard set, reset map, endpoint set as well as the switching set. We present a pseudospectral (PS) knotting method that discretizes the continuous-time variables of the problem. The discrete event conditions are imposed over the PS knots leading to a large, sparse, mixed-variable programming (MVP) problem. The Karush-Kuhn-Tucker conditions for the MVP are transformed in a manner that makes them closely resemble the discretized necessary conditions obtained from the hybrid minimum principle. A set of closure conditions are introduced to facilitate commuting the operations of dualization and discretization. An immediate consequence of this is a hybrid covector mapping theorem that provides an order-preserving transformation of the Lagrange multipliers associated with the discretized problem to the discretized covectors associated with the hybrid optimal control problem.

Dissipative Decomposition and Feedback Stabilization of Nonlinear Control Systems

Hudon, Nicolas
Fonte: Quens University Publicador: Quens University
Tipo: Tese de Doutorado
EN; EN
Relevância na Pesquisa
85.92%
This dissertation considers the problem of approximate dissipative potentials construction and their use in smooth feedback stabilization of nonlinear control systems. For mechanical systems, dissipative potentials, usually a generalized Hamiltonian function, can be derived from physical intuition. When a dissipative Hamiltonian is not available, one can rely on dissipative Hamiltonian realization techniques, as proposed recently by Cheng and coworkers. Extensive results are available in the literature for (robust) stabilization based on the obtained potential. For systems of interest in chemical engineering, especially systems with mass action kinetics, energy is often ill-defined. Moreover, realization techniques are difficult to apply, due to the nonlinearities associated with the reaction terms. Approximate dissipative realization techniques have been considered by many researchers for analysis and feedback design of controllers in the context of chemical processes. The objective of this thesis is to study the construction of local dissipative potentials and their application to solve stabilization problems. The present work employs the geometric stabilization approach proposed by Jurdjevic and Quinn, refined by Faubourg and Pomet...

Flexible Nonlinear Voltage Control Design for Power Systems

Gordon, Mark; Hill, David
Fonte: Institute of Electrical and Electronics Engineers (IEEE Inc) Publicador: Institute of Electrical and Electronics Engineers (IEEE Inc)
Tipo: Conference paper
Relevância na Pesquisa
65.86%
This paper presents the Direct Feedback Linearization (DFL) technique as a simple and flexible nonlinear control method in designing robust nonlinear excitation controllers for stability enhancement and voltage regulation of power systems. This technique

Thomas decompositions of parametric nonlinear control systems

Lange-Hegermann, Markus; Robertz, Daniel
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 03/12/2012
Relevância na Pesquisa
75.77%
This paper presents an algorithmic method to study structural properties of nonlinear control systems in dependence of parameters. The result consists of a description of parameter configurations which cause different control-theoretic behaviour of the system (in terms of observability, flatness, etc.). The constructive symbolic method is based on the differential Thomas decomposition into disjoint simple systems, in particular its elimination properties.

Model Reduction for Nonlinear Control Systems using Kernel Subspace Methods

Bouvrie, Jake; Hamzi, Boumediene
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
75.86%
We introduce a data-driven order reduction method for nonlinear control systems, drawing on recent progress in machine learning and statistical dimensionality reduction. The method rests on the assumption that the nonlinear system behaves linearly when lifted into a high (or infinite) dimensional feature space where balanced truncation may be carried out implicitly. This leads to a nonlinear reduction map which can be combined with a representation of the system belonging to a reproducing kernel Hilbert space to give a closed, reduced order dynamical system which captures the essential input-output characteristics of the original model. Empirical simulations illustrating the approach are also provided.

On the output-input stability property for multivariable nonlinear control systems

Liberzon, Daniel
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 19/05/2002
Relevância na Pesquisa
75.8%
We study the recently introduced notion of output-input stability, which is a robust variant of the minimum-phase property for general smooth nonlinear control systems. The subject of this paper is developing the theory of output-input stability in the multi-input, multi-output setting. We show that output-input stability can be viewed as a combination of two system properties, one related to detectability and the other to left-invertibility. For systems affine in controls, we provide a necessary and sufficient condition for output-input stability, which relies on Hirschorn's nonlinear structure algorithm.

Symbolic models for nonlinear control systems affected by disturbances

Borri, Alessandro; Pola, Giordano; Di Benedetto, Maria Domenica
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 26/01/2012
Relevância na Pesquisa
75.86%
In the last few years there has been a growing interest in the use of symbolic models for the formal veri?cation and control design of purely continuous or hybrid systems. Symbolic models are abstract descriptions of continuous systems where one symbol corresponds to an "aggregate" of continuous states. In this paper we face the problem of deriving symbolic models for nonlinear control systems affected by disturbances. The main contribution of this paper is in proposing symbolic models that can be eff?ectively constructed and that approximate nonlinear control systems aff?ected by disturbances in the sense of alternating approximate bisimulation.; Comment: 14 pages, 3 figures

Discrete Control Systems

Lee, Taeyoung; Leok, Melvin; McClamroch, N. Harris
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 26/05/2007
Relevância na Pesquisa
65.95%
Discrete control systems, as considered here, refer to the control theory of discrete-time Lagrangian or Hamiltonian systems. These discrete-time models are based on a discrete variational principle, and are part of the broader field of geometric integration. Geometric integrators are numerical integration methods that preserve geometric properties of continuous systems, such as conservation of the symplectic form, momentum, and energy. They also guarantee that the discrete flow remains on the manifold on which the continuous system evolves, an important property in the case of rigid-body dynamics. In nonlinear control, one typically relies on differential geometric and dynamical systems techniques to prove properties such as stability, controllability, and optimality. More generally, the geometric structure of such systems plays a critical role in the nonlinear analysis of the corresponding control problems. Despite the critical role of geometry and mechanics in the analysis of nonlinear control systems, nonlinear control algorithms have typically been implemented using numerical schemes that ignore the underlying geometry. The field of discrete control system aims to address this deficiency by restricting the approximation to choice of a discrete-time model...

A Vector Small-Gain Theorem for General Nonlinear Control Systems

Karafyllis, Iasson; Jiang, Zhong-Ping
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 05/04/2009
Relevância na Pesquisa
75.9%
A new Small-Gain Theorem is presented for general nonlinear control systems. The novelty of this research work is that vector Lyapunov functions and functionals are utilized to derive various input-to-output stability and input-to-state stability results. It is shown that the proposed approach recovers several recent results as special instances and is extendible to several important classes of control systems such as large-scale complex systems, nonlinear sampled-data systems and nonlinear time-delay systems. An application to a biochemical circuit model illustrates the generality and power of the proposed vector small-gain theorem.; Comment: Submitted to IEEE Transactions on Automatic Control

Symbolic Models for Nonlinear Control Systems: Alternating Approximate Bisimulations

Pola, Giordano; Tabuada, Paulo
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 27/07/2007
Relevância na Pesquisa
75.84%
Symbolic models are abstract descriptions of continuous systems in which symbols represent aggregates of continuous states. In the last few years there has been a growing interest in the use of symbolic models as a tool for mitigating complexity in control design. In fact, symbolic models enable the use of well known algorithms in the context of supervisory control and algorithmic game theory, for controller synthesis. Since the 1990's many researchers faced the problem of identifying classes of dynamical and control systems that admit symbolic models. In this paper we make a further progress along this research line by focusing on control systems affected by disturbances. Our main contribution is to show that incrementally globally asymptotically stable nonlinear control systems with disturbances admit symbolic models. When specializing these results to linear systems, we show that these symbolic models can be easily constructed.

Quasiperiodic AlGaAs superlattices for neuromorphic networks and nonlinear control systems

Malyshev, K. V.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 08/02/2015
Relevância na Pesquisa
75.81%
The application of quasiperiodic AlGaAs superlattices as a nonlinear element of the FitzHugh-Nagumo neuromorphic network is proposed and theoretically investigated on the example of Fibonacci and figurate superlattices. The sequences of symbols for the figurate superlattices were produced by decomposition of the Fibonacci superlattices' symbolic sequences. A length of each segment of the decomposition was equal to the corresponding figurate number. It is shown that a nonlinear network based upon Fibonacci and figurate superlattices provides better parallel filtration of a half-tone picture than a network based upon traditional diodes which have cubic voltage-current characteristics. It was found that the figurate superlattice F011(1) as a nonlinear network's element provides the filtration error almost twice less than the conventional "cubic" diode. These advantages are explained by a wavelike shape of the decreasing part of the quasiperiodic superlattice's voltage-current characteristic, which leads to multistability of the network's cell. This multistability promises new interesting nonlinear dynamical phenomena. A variety of wavy forms of voltage-current characteristics opens up new interesting possibilities for quasiperiodic superlattices and especially for figurate superlattices in many areas - from nervous system modeling to nonlinear control systems development; Comment: 19 pages...

Balanced Reduction of Nonlinear Control Systems in Reproducing Kernel Hilbert Space

Bouvrie, Jake; Hamzi, Boumediene
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 12/11/2010
Relevância na Pesquisa
75.83%
We introduce a novel data-driven order reduction method for nonlinear control systems, drawing on recent progress in machine learning and statistical dimensionality reduction. The method rests on the assumption that the nonlinear system behaves linearly when lifted into a high (or infinite) dimensional feature space where balanced truncation may be carried out implicitly. This leads to a nonlinear reduction map which can be combined with a representation of the system belonging to a reproducing kernel Hilbert space to give a closed, reduced order dynamical system which captures the essential input-output characteristics of the original model. Empirical simulations illustrating the approach are also provided.

L ∞ -bounded robust control of nonlinear cascade systems

Huang, Shoudong; James, Matthew; Jiang, Zhong-Ping
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
75.94%
In this paper, we consider the L∞-bounded robust control problem for a class of nonlinear cascade systems with disturbances. Sufficient conditions are provided under which a hard bound is imposed on the system performance measure. The backstepping appro

Iterative Controller Optimization for Nonlinear Systems

Sjoberg, J; De Bruyne, Franky; Agarwal, M; Anderson, Brian; Gevers, Michel; Kraus, F J; Linard, N
Fonte: Pergamon-Elsevier Ltd Publicador: Pergamon-Elsevier Ltd
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
65.92%
Recently, a data-driven model-free control design method has been proposed in Hjalmarsson et al. (Proceedings of the Conference on Decision and Control, Orlando, FL, 1994, pp. 1735-1740; IEEE Control Systems Mag. 18 (1998) 26) for linear systems. It is based on the minimization of a control criterion with respect to the controller parameters using an iterative gradient technique. In this paper, we extend this method to the case where both the plant and the controller can be nonlinear. It is shown that an estimate of the gradient of the control criterion can be constructed using only signal-based information obtained from closed-loop experiments. The obtained estimate contains a bias which depends on the local nonlinearity of the noise description of the closed-loop system which can be expected to be small in many practical situations. As a side effect the linear model-free control design method is reobtained in a new way.

Recursive Identification of Nonlinear Plants Operating in Closed Loop Using Kernel Representations

De Bruyne, Franky; Anderson, Brian; Landau, I D
Fonte: Pergamon-Elsevier Ltd Publicador: Pergamon-Elsevier Ltd
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
65.92%
In this paper, we extend the family of algorithms presented in Algorithms for identification of continuous time nonlinear systems. A passivity approach. In A. Isidori, F. Ramnabhi-Lagarrigue, & W. Respondek (Eds.), Nonlinear control in the year 2000, vol. 2 (pp. 13-44) Berlin: Springer; (Automatica 37 (2000) 469) for the identification of continuous time nonlinear plants operating in closed loop. The new algorithms presuppose that one can construct a stable kernel representation for the "to be identified model" structure. The new theory results in a less restrictive passivity condition. The main novelty is that the identification of unstable plants can be tackled by an appropriate choice of the kernel representation, i.e. there is an additional degree of freedom when constructing the kernel representation. The implicit stability of the controller is still required by the new passivity condition.

Nonlinear H-∞ Control: Practicality of Implementing the Cheap Sensor Case

Helton, J W; James, Matthew; McEneaney, W M
Fonte: Institute of Electrical and Electronics Engineers (IEEE Inc) Publicador: Institute of Electrical and Electronics Engineers (IEEE Inc)
Tipo: Conference paper
Relevância na Pesquisa
75.86%
In [5] we introduced a recipe for nonlinear H∞ controllers which takes advantage of extra perfect measurements and stated a theorem to the effect that this controller yielded the best possible "H∞" performance. Pure state feedback is an extreme situat

On Hybrid Impulsive and Switching Systems and Application to Nonlinear Control

Guan, Zhi-Hong; Hill, David; Shen, Xuemin (Sherman)
Fonte: Institute of Electrical and Electronics Engineers (IEEE Inc) Publicador: Institute of Electrical and Electronics Engineers (IEEE Inc)
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
65.87%
In this note, a new class of hybrid impulsive and switching models is introduced and their asymptotic stability properties are investigated. Using switched Lyapunov functions, some new general criteria for exponential stability and asymptotic stability with arbitrary and conditioned impulsive switching are established. In addition, a new hybrid impulsive and switching control strategy for nonlinear systems is developed. A typical example, the unified chaotic system, is given to illustrate the theoretical results.