Papers by Magdi S Mahmoud
2009 IEEE Symposium on Industrial Electronics & Applications, 2009
ABSTRACT Damping local mode and inter-area oscillations are two critical issues for optimal power... more ABSTRACT Damping local mode and inter-area oscillations are two critical issues for optimal power flow and stability in a power system. Power system stabilizers (PSSs) are applied to damp these oscillations. Conventional algorithms of PSS design are based on classical control theory and eigen values based calculation and involve numerous mathematical calculations which may not present an accurate solution. In this paper, a particle swarm optimization (PSO) based PSS design is suggested which is based on time domain response of power system and also is robust for the overall credible disturbances in power system. Two-area (four-machine 11-bus) power system is considered as the case study in this paper. PSS parameters are obtained for four PSS connected to four generators. Finally, the effectiveness of the proposed algorithm is evaluated for damping the system oscillations during overall disturbances. The simulation results illustrate this issue.
The networked control system (NCS) design for continuoustime systems with probabilistic delays is... more The networked control system (NCS) design for continuoustime systems with probabilistic delays is discussed in this paper. The delay is assumed to follow a given probability density function. A design scheme for the observer-based output feedback controller is proposed to render the closedloop networked system exponentially mean-square stable with H∞ performance requirement. The design method is fulfilled through solving linear matrix inequalities. A numerical example is provided to show the advantages of the proposed technique.
Complete results for the delay-dependent robust stability and feedback stabilization of linear ne... more Complete results for the delay-dependent robust stability and feedback stabilization of linear neutral systems with unknown-but-bounded uncertainties are developed. New linear matrix inequalities-based delay-dependent stability criteria are derived in a systematic way using a new expanded state-space representation and a new Lyapunov-Krasovskii functional. The results are established without relying on overbounding. Solution to delay-dependent statefeedback stabilization and H∞ synthesis are then obtained. Numerical examples are presented to illustrate the theory.
A new delay-dependent criterion is developed for robust stability of linear discrete-time singula... more A new delay-dependent criterion is developed for robust stability of linear discrete-time singular systems with state-delay and parametric uncertainties. The time-delay is varying between known bounds and the uncertainties are assumed to be time-invariant and norm-bounded appearing in the state and delay matrices. The new criterion is achieved by an expanded state-space system representation. A solution to delay-dependent stabilization is attained based on guaranteed cost and H� control approaches. All the developed results are conveniently cast in the format of linear matrix inequalities (LMIs) and numerical examples are presented.
To my honest and diligent wife, Wang Fangyu To my lovely daughter, Xia Jingshu YX Contents Prefac... more To my honest and diligent wife, Wang Fangyu To my lovely daughter, Xia Jingshu YX Contents Preface xv Acknowledgments xvii 1 Introduction 1.1 Overview 1.2 Basic Concepts of Faults 1.3 Classification of Fault Detection Methods 1.3.1 Hardware redundancy based fault detection 1.3.2 Plausibility test 1.3.3 Signal-based fault diagnosis 1.3.4 Model-based fault detection 1.4 Types of Fault-Tolerant Control System 1.5 Objectives and Structure of AFTCS 1.6 Classification of Reconfigurable Control Methods 1.6.1 Classification based on control algorithms 1.6.2 Classification based on field of application 1.7 Outline of the Book 1.7.1 Methodology 1.
This paper focuses on the controller fragility and performance deterioration issues due to inaccu... more This paper focuses on the controller fragility and performance deterioration issues due to inaccuracies in controller implementation. It addresses the problem of non-fragile adaptive control problem for a class of continuous-time systems with state-delays and norm-bounded uncertainties against controller gain variations. Adaptive control schemes are constructed for the case of known gain pertubation bounds and then extended to accomodate unknown norm-bounded perturbations. All the developed results are conveniently expressed in LMI format. A detailed simulation results is presented to demonstrate the developed theory.
International Journal of Innovative Computing Information and Control, 2007
The problem of designing a resilient observer-based dynamic feedback con- troller for a class of ... more The problem of designing a resilient observer-based dynamic feedback con- troller for a class of uncertain systems with time-varying delays against controller per- turbations is investigated. The uncertainties are parametric and norm-bounded. The objective is to derive tractable synthesis conditions for the resilient dynamic feedback de- sign. All the developed results are cast in the format of linear matrix inequalities (LMIs). Previous related results are recovered. A simulation example is presented.
IMA Journal of Mathematical Control and Information, Oct 1, 2011
Abstract—Fault-tolerant control (FTC) is an integral component in industrial processes as it enab... more Abstract—Fault-tolerant control (FTC) is an integral component in industrial processes as it enables the system to continue robust operation under some conditions. In this paper, an FTC scheme is proposed for interconnected systems within an integrated design framework to yield a timely monitoring and detection of fault and reconfiguring the controller according to those faults. The unscented Kalman filter (UKF)-based fault
detection and diagnosis system is initially run on the main plant and parameter estimation is being done for the local faults. This critical information is shared through information fusion to the main system where the whole system is being decentralized using the overlapping decomposition technique. Using this parameter estimates of decentralized subsystems, a model predictive control (MPC) adjusts its parameters according to the fault scenarios thereby striving to maintain the stability of the system. Experimental results on interconnected continuous time stirred tank reactors (CSTR) with recycle and quadruple tank system indicate that the proposed method is capable to correctly identify various faults, and then controlling the system under some conditions.
Nova Science Publishers– Signal Processing: New Research, Dec 1, 2013
Feedback is an important element in practical systems. However, it brings challenging situations ... more Feedback is an important element in practical systems. However, it brings challenging situations in its route. In this paper, we deal with the closed-loop identification of a two-tank process used in industry. The identified model is then utilized to develop H-infiniti and sliding mode controllers to develop robustness of the system. It is shown that these controllers guarantee a satisfactory performance in the face of both model/parametric uncertainties and external disturbances. The designed controllers have been successfully tested through extensive simulation. In addition, this paper shows that the designed linear and nonlinear robust controllers far outperform traditional controllers such as P, PI, and PID, in the face of parametric model uncertainties and the effects of external disturbances. The successful use of the designed robust controllers, which are H-infiniti, sliding-mode and high-order sliding mode controllers, encouraging their extension to other physical systems as well.
J Optimiz Theor Appl, 1999
J Franklin Inst Eng Appl Math, 2008
The 2014 2nd International Conference on Systems and Informatics, Nov 1, 2014
Circ Syst Signal Process, 2009
Http Dx Doi Org 10 1080 03081079 2014 883712, Mar 4, 2014
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Papers by Magdi S Mahmoud
detection and diagnosis system is initially run on the main plant and parameter estimation is being done for the local faults. This critical information is shared through information fusion to the main system where the whole system is being decentralized using the overlapping decomposition technique. Using this parameter estimates of decentralized subsystems, a model predictive control (MPC) adjusts its parameters according to the fault scenarios thereby striving to maintain the stability of the system. Experimental results on interconnected continuous time stirred tank reactors (CSTR) with recycle and quadruple tank system indicate that the proposed method is capable to correctly identify various faults, and then controlling the system under some conditions.
detection and diagnosis system is initially run on the main plant and parameter estimation is being done for the local faults. This critical information is shared through information fusion to the main system where the whole system is being decentralized using the overlapping decomposition technique. Using this parameter estimates of decentralized subsystems, a model predictive control (MPC) adjusts its parameters according to the fault scenarios thereby striving to maintain the stability of the system. Experimental results on interconnected continuous time stirred tank reactors (CSTR) with recycle and quadruple tank system indicate that the proposed method is capable to correctly identify various faults, and then controlling the system under some conditions.