The Experts below are selected from a list of 315 Experts worldwide ranked by ideXlab platform
Yuzhen Wang - One of the best experts on this subject based on the ideXlab platform.
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Adaptive parallel simultaneous stabilization of two nonlinear descriptor systems via Hamiltonian Function method
2010Co-Authors: Liying Sun, Yuzhen WangAbstract:This paper investigates the adaptive parallel simultaneous stabilization problem of two nonlinear descriptor systems via the Hamiltonian Function method. Firstly, under the Hamiltonian realizations of the two nonlinear descriptor systems and an adaptive output feedback law, two nonlinear descriptor systems are equivalently transformed into two nonlinear Hamiltonian differential-algebraic systems by nonsingular transformations, and then the two systems are combined to generate an augmented dissipative Hamiltonian differential-algebraic system by using the system-augmentation technique. Based on the dissipative system, the adaptive parallel simultaneous stabilization controller of two nonlinear descriptor systems is designed via the Hamiltonian Function method.
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Simultaneous stabilization of a class of nonlinear descriptor systems via Hamiltonian Function method
Science in China Series F: Information Sciences, 2009Co-Authors: Liying Sun, Yuzhen WangAbstract:This paper studies simultaneous stabilization of a class of nonlinear descriptor systems via the Hamiltonian Function method. Firstly, based on the Hamiltonian realization of the nonlinear descriptor systems and a suitable output feedback, two nonlinear descriptor systems are equivalently transformed into two nonlinear Hamiltonian differential-algebraic systems by a nonsingular transformation, and a sufficient condition for two closed-loop systems to be impulse-free is given. The two systems are then combined to generate an augmented dissipative Hamiltonian differential-algebraic system by using the system-augmentation technique, based on which a simultaneous stabilization controller and a robust simultaneous stabilization controller are designed for the two systems. Secondly, the case of more than two nonlinear descriptor systems is investigated, and two new results are proposed for the simultaneous stabilization and robust simultaneous stabilization, respectively. Finally, an illustrative example is studied by using the results proposed in this paper, and simulations show that the simultaneous stabilization controllers obtained in this paper work very well.
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Decentralized Excitation Control of Multi-machine Multi-load Power Systems Using Hamiltonian Function Method
Acta Automatica Sinica, 2009Co-Authors: Yanhong Liu, Yuzhen WangAbstract:Abstract Using the Hamiltonian Function method, we investigate the excitation control of multi-machine multi-load power systems presented by nonlinear diffierential algebraic equations. First, the power system is reformulated as a novel Hamiltonian realization structure via pre-feedback state control. Then, based on the dissipative Hamiltonian realization of the system, a decentralized nonlinear excitation control scheme is constructed. The stability of the closed loop system is analyzed as well. The proposed strategy takes advantage of the intrinsic properties especially including the internal power balance of the power system. Simulation illustrates the effectiveness of the control strategy.
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Robust adaptive control of synchronous generators with SMES unit via Hamiltonian Function method
International Journal of Systems Science, 2007Co-Authors: Yuzhen WangAbstract:Superconducting Magnetic Energy Storage (SMES) units can be used to enhance the stability of power systems. Using Hamiltonian Function method, this article investigates robust adaptive control design for synchronous generators with such a unit, and proposes an energy-based robust adaptive controller for the systems with disturbances and unknown parameters. The generator used in this article is a 4th order model with both excitation and steam valve controls. It is shown that the generator with one SMES unit can be changed as a dissipative Hamiltonian system, with which the energy-based robust adaptive control law can be designed for the system by using the structural properties of dissipative Hamiltonian systems. Study on simulations shows that the controller proposed in this article works very well.
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Adaptive H-infinity control of synchronous generators with steam valve via Hamiltonian Function method
Journal of Control Theory and Applications, 2006Co-Authors: Yuzhen WangAbstract:Based on Hamiltonian formulation, this paper proposes a design approach to nonlinear feedback excitation control of synchronous generators with steam valve control, disturbances and unknown parameters. It is shown that the dynamics of the synchronous generators can be expressed as a dissipative Hamiltonian system, based on which an adaptive H-infinity controller is then designed for the systems by using the structure properties of dissipative Hamiltonian systems. Simulations show that the controller obtained in this paper is very effective.
Daizhan Cheng - One of the best experts on this subject based on the ideXlab platform.
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adaptive h excitation control of multimachine power systems via the Hamiltonian Function method
International Journal of Control, 2004Co-Authors: Yuzhen Wang, Daizhan Cheng, Yanhong LiuAbstract:Using the Hamiltonian Function method, this paper investigates the adaptive H ∞ excitation control of multimachine power systems with disturbances and parameter perturbations. A key step in applying the Hamiltonian Function method to the multimachine system is to express the system as a dissipative Hamiltonian system, i.e. to complete dissipative Hamiltonian realization (DHR). By using pre-feedback technique, this paper expresses the multimachine power system as a dissipative Hamiltonian system. Then, the stability analysis of the achieved dissipative Hamiltonian system is proceeded. Finally, based on the achieved DHR form, the adaptive H ∞ excitation control of the multimachine power system is investigated and a decentralized simple excitation control strategy is obtained. Simulations on a six-machine system show that the adaptive H ∞ excitation control strategy proposed in the paper is more effective than some other control schemes.
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Adaptive H ∞ excitation control of multimachine power systems via the Hamiltonian Function method
International Journal of Control, 2004Co-Authors: Yuzhen Wang, Daizhan Cheng, Yanhong LiuAbstract:Using the Hamiltonian Function method, this paper investigates the adaptive H ∞ excitation control of multimachine power systems with disturbances and parameter perturbations. A key step in applying the Hamiltonian Function method to the multimachine system is to express the system as a dissipative Hamiltonian system, i.e. to complete dissipative Hamiltonian realization (DHR). By using pre-feedback technique, this paper expresses the multimachine power system as a dissipative Hamiltonian system. Then, the stability analysis of the achieved dissipative Hamiltonian system is proceeded. Finally, based on the achieved DHR form, the adaptive H ∞ excitation control of the multimachine power system is investigated and a decentralized simple excitation control strategy is obtained. Simulations on a six-machine system show that the adaptive H ∞ excitation control strategy proposed in the paper is more effective than some other control schemes.
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Brief Generalized Hamiltonian realization of time-invariant nonlinear systems
Automatica, 2003Co-Authors: Yuzhen Wang, Daizhan ChengAbstract:A key step in applying the Hamiltonian Function method is to express the system under consideration into a generalized Hamiltonian system with dissipation, which yields the so-called generalized Hamiltonian realization (GHR). In this paper, we investigate the problem of GHR. Several new methods and the corresponding sufficient conditions are presented. A major result is that if the Jacobian matrix of a time-invariant nonlinear system is nonsingular, the system has a GHR whose structure matrix and Hamiltonian Function are given in simple forms. Then the orthogonal decomposition method and a sufficient condition for the feedback dissipative realization are proposed.
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Brief Nonlinear decentralized controller design for multimachine power systems using Hamiltonian Function method
Automatica, 2002Co-Authors: Daizhan Cheng, Shengwei MeiAbstract:In this paper, we first express a multimachine power system as a Hamiltonian control system with dissipation. Then, using the Hamiltonian Function method a decentralized excitation control scheme, as a static measurable feedback, is proposed to stabilize the multimachine power system. Then, it is shown that the control scheme with properly chosen parameters is also an H"~ control, which solves the problem of disturbance attenuation simultaneously. Finally, the design technique is demonstrated by a three-machine power system.
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Stabilization of synchronous generators with the Hamiltonian Function approach
International Journal of Systems Science, 2001Co-Authors: Yuzhen Wang, Daizhan Cheng, Yiguang HongAbstract:Using the Hamiltonian Function approach, this paper proposes an energy-based stabilizing method for a fifth-order model of synchronous generators to keep the terminal machine voltage (output) remaining at a given expected value. By constructing a Hamiltonian Function as the total energy Function for the fifth-order model and changing the system into a forced Hamiltonian system with dissipation, an energy-based Lyapunov Function is obtained. As the result, a suitable stabilizing controller is constructed for the system. Simulation shows the effectiveness of the stabilizing method proposed in this paper.
Gaurav Dhar - One of the best experts on this subject based on the ideXlab platform.
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Continuity/constancy of the Hamiltonian Function in a Pontryagin maximum principle for optimal sampled-data control problems with free sampling times
Mathematics of Control Signals and Systems, 2019Co-Authors: Loic Bourdin, Gaurav DharAbstract:In a recent paper by Bourdin and Trélat, a version of the Pontryagin maximum principle (in short, PMP) has been stated for general nonlinear finite-dimensional optimal sampled-data control problems. Unfortunately, their result is only concerned with fixed sampling times, and thus, it does not take into account the possibility of free sampling times. The present paper aims to fill this gap in the literature. Precisely, we establish a new version of the PMP that can handle free sampling times. As in the aforementioned work by Bourdin and Trélat, we obtain a first-order necessary optimality condition written as a nonpositive averaged Hamiltonian gradient condition. Furthermore, from the freedom of choosing sampling times, we get a new and additional necessary optimality condition which happens to coincide with the continuity of the Hamiltonian Function. In an autonomous context, even the constancy of the Hamiltonian Function can be derived. Our proof is based on the Ekeland variational principle. Finally, a linear–quadratic example is numerically solved using shooting methods, illustrating the possible discontinuity of the Hamiltonian Function in the case of fixed sampling times and highlighting its continuity in the instance of optimal sampling times.
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Continuity/constancy of the Hamiltonian Function in a Pontryagin maximum principle for optimal sampled-data control problems with free sampling times
Mathematics of Control Signals and Systems, 2019Co-Authors: Loic Bourdin, Gaurav DharAbstract:In a recent paper by Bourdin and Trelat, a version of the Pontryagin maximum principle (in short, PMP) has been stated for general nonlinear finite-dimensional optimal sampled-data control problems. Unfortunately, their result is only concerned with fixed sampling times, and thus, it does not take into account the possibility of free sampling times. The present paper aims to fill this gap in the literature. Precisely, we establish a new version of the PMP that can handle free sampling times. As in the aforementioned work by Bourdin and Trelat, we obtain a first-order necessary optimality condition written as a nonpositive averaged Hamiltonian gradient condition. Furthermore, from the freedom of choosing sampling times, we get a new and additional necessary optimality condition which happens to coincide with the continuity of the Hamiltonian Function. In an autonomous context, even the constancy of the Hamiltonian Function can be derived. Our proof is based on the Ekeland variational principle. Finally, a linear–quadratic example is numerically solved using shooting methods, illustrating the possible discontinuity of the Hamiltonian Function in the case of fixed sampling times and highlighting its continuity in the instance of optimal sampling times.
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continuity constancy of the Hamiltonian Function in a pontryagin maximum principle for optimal sampled data control problems with free sampling times
Mathematics of Control Signals and Systems, 2019Co-Authors: Loic Bourdin, Gaurav DharAbstract:In a recent paper by Bourdin and Trelat, a version of the Pontryagin maximum principle (in short, PMP) has been stated for general nonlinear finite-dimensional optimal sampled-data control problems. Unfortunately, their result is only concerned with fixed sampling times, and thus, it does not take into account the possibility of free sampling times. The present paper aims to fill this gap in the literature. Precisely, we establish a new version of the PMP that can handle free sampling times. As in the aforementioned work by Bourdin and Trelat, we obtain a first-order necessary optimality condition written as a nonpositive averaged Hamiltonian gradient condition. Furthermore, from the freedom of choosing sampling times, we get a new and additional necessary optimality condition which happens to coincide with the continuity of the Hamiltonian Function. In an autonomous context, even the constancy of the Hamiltonian Function can be derived. Our proof is based on the Ekeland variational principle. Finally, a linear–quadratic example is numerically solved using shooting methods, illustrating the possible discontinuity of the Hamiltonian Function in the case of fixed sampling times and highlighting its continuity in the instance of optimal sampling times.
Yanhong Liu - One of the best experts on this subject based on the ideXlab platform.
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CDC - Finite-time Stabilization and Robust Control of Stochastic Nonlinear System Based on Hamiltonian Realization
2019 IEEE 58th Conference on Decision and Control (CDC), 2019Co-Authors: Min Wang, Yanhong Liu, Guizhou CaoAbstract:The finite-time stabilization and robust control of stochastic nonlinear systems was discussed in this paper. First, by transforming the considered system to its equivalent Hamiltonian system, we showed that the stochastic dissipative Hamiltonian system was finite-time stable in probability if the Hamiltonian Function and internal damping matrix possessed some structures. Then, we utilized the energy shaping and damping injection techniques to reformulate the internal structures and Hamiltonian Function of the stochastic Hamiltonian system and constructed a finite-time stabilization controller. Finally, a robust finite-time controller was put forward for uncertain stochastic nonlinear systems by using the Hamiltonian Function to construct a solution of Hamiltonian-Jacobi Inequality. Numerical simulations results demonstrated the effectiveness of the proposed stabilization and robust stabilization methods.
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Decentralized robust control of multiple static var compensators via Hamiltonian Function method
Journal of Control Theory and Applications, 2013Co-Authors: Yanhong Liu, Bing Chu, Honghai Tang, Lijun ZhangAbstract:Using the energy-based Hamiltonian Function method, this paper investigates the decentralized robust nonlinear control of multiple static var compensators (SVCs) in multimachine multiload power systems. First, the uncertain nonlinear differential algebraic equation model is constructed for the power system. Then, the dissipative Hamiltonian realization of the system is completed by means of variable transformation and prefeedback control. Finally, based on the obtained dissipative Hamiltonian realization, a decentralized robust nonlinear controller is put forward. The proposed controller can effectively utilize the internal structure and the energy balance property of the power system. Simulation results verify the effectiveness of the control scheme.
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Robust excitation control of multi-machine multi-load power systems using Hamiltonian Function method
Frontiers of Electrical and Electronic Engineering in China, 2011Co-Authors: Yanhong LiuAbstract:Using an energy-based Hamiltonian Function method, this paper investigates the robust excitation control of multi-machine multi-load power systems described by a set of uncertain differential algebraic equations. First, we complete the dissipative Hamiltonian realization of the power system and adjust its operating point by the means of pre-feedback control. Then, based on the obtained Hamiltonian realization, we discuss the robust excitation control of the power system and put forward an H ∞ excitation control strategy. Simulation results demonstrate the effectiveness of the control scheme.
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h excitation control of multi machine multi load power systems via Hamiltonian Function method
International Conference on Control and Automation, 2010Co-Authors: Yanhong Liu, Lijun ZhangAbstract:This paper investigates the H ∞ excitation control of multi-machine multi-load power systems via the Hamiltonian Function method. First, we reformulate the power system as a dissipative Hamiltonian system by using a proper feedback control. The proposed Hamiltonian realization can utilize the internal energy balance in the power system and facilitate the stability analysis. Then, based on the obtained Hamiltonian realization, we discuss the H ∞ excitation control of the multi-machine multi-load power system and put forward a decentralized H ∞ excitation control strategy. The stability of the closed loop system is analyzed. Simulation results demonstrate the effectiveness of the control scheme.
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ICCA - H ∞ excitation control of multi-machine multi-load power systems via Hamiltonian Function method
IEEE ICCA 2010, 2010Co-Authors: Yanhong Liu, Lijun ZhangAbstract:This paper investigates the H ∞ excitation control of multi-machine multi-load power systems via the Hamiltonian Function method. First, we reformulate the power system as a dissipative Hamiltonian system by using a proper feedback control. The proposed Hamiltonian realization can utilize the internal energy balance in the power system and facilitate the stability analysis. Then, based on the obtained Hamiltonian realization, we discuss the H ∞ excitation control of the multi-machine multi-load power system and put forward a decentralized H ∞ excitation control strategy. The stability of the closed loop system is analyzed. Simulation results demonstrate the effectiveness of the control scheme.
Y. Le Gorrec - One of the best experts on this subject based on the ideXlab platform.
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The Port Hamiltonian approach to modeling and control of Continuous Stirred Tank Reactors.
Journal of Process Control, 2011Co-Authors: N.h. Hoang, Françoise Couenne, Christian Jallut, Y. Le GorrecAbstract:This paper proposes a thermodynamical pseudo Hamiltonian formulation of Continuous Stirred Tank Reactor model in which takes place some chemical reaction. This is done both in the isothermal and non isothermal cases. It is shown that the Gibbs free energy and the opposite of entropy can be chosen as Hamiltonian Function respectively. For the non isothermal case, the so called Interconnection and Damping Assignment Passivity Based Control method is applied to stabilize the system at a desired state. For this general reaction scheme, the control problem is shown to be easy to solve as soon as the closed loop Hamiltonian Function is chosen to be proportional to the so called thermodynamic availability Function. Simulation results based on a simple first order reaction and operating conditions leading to multiple steady states of the CSTR are given to validate the proposed control design procedure.
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Port Hamiltonian based modeling and control of exothermic Continuous Stirred Tank Reactors
IFAC Proceedings Volumes, 2010Co-Authors: H. Hoang, Françoise Couenne, Christian Jallut, Y. Le GorrecAbstract:Abstract This paper proposes a thermodynamically consistent pseudo Hamiltonian formulation of Continuous Stirred Tank Reactor model in which takes place one general reaction scheme. This is done both in the isothermal and non isothermal cases. It is shown that Gibbs free energy and opposite of entropy can be chosen as Hamiltonian Function respectively. For the non isothermal case, the so called Interconnection and Damping Assignment Passivity Based Control method is applied. Even for a general reaction the control problem is shown to be easy to solve as soon as closed loop Hamiltonian Function is chosen to be proportional to the so called thermodynamic Availability Function.
