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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.

Power system stability studies using Liapunov methods

Metwally, Magda Mohsen January 1971 (has links)
The transient stability of power systems is investigated using Liapunov's direct method. Willems' method is applied to three-and four-machine power systems with the effect of damping included. The distribution of damping among the machines of a multi-machine system is studied, and optimum ratios are derived. An extension of Willems' method is used to include governor action in the system representation. Finally, the effect of flux decay on stability regions is studied using Chen's method. / Applied Science, Faculty of / Electrical and Computer Engineering, Department of / Graduate

Modeling with Liapunov functions

Nordahl, Donald Marvin, 1942- January 1966 (has links)
No description available.

Design of sampled-data control systems using the second method of Liapunov

Ramirez-Guzman, Gustavo, 1940- January 1966 (has links)
No description available.

The second method of Liapunov and the design of linear systems

Higgins, Walter Thomas, 1938- January 1964 (has links)
No description available.

The stability theory of difference equations using Liapunov's direct method /

Gordon, Sheldon P. January 1969 (has links)
No description available.

Systematic means of generating Liapunov functions for automatic control systems

Ambegaonkar, Prakash Madhavrad, January 1969 (has links)
Thesis (M.S.)--University of Wisconsin--Madison, 1969. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

The Application of Lyapunov function to power systme stability analysis and control

Vongsuriya, Khien January 1968 (has links)
Lyapunov functions are applied to the power system studies. Three types of power system problems are investigated, namely, the determination of asymptotic stability regions of a nonlinear power system for fault and switching transient stability studies, the systematic optimum parameter setting of power system controllers, and the determination of linear and nonlinear optimum stabilising signals as functions of state variables for both nonlinear and linearized power systems. To investigate and construct the transient stability region of a synchronous machine connected to infinite bus through a transmission system after fault and switching, high degree Lyapunov function series generated by Zubov's method is applied. For the optimum parameter setting of a power system, a computation technique based on the method of gradient has been developed to adjust the system parameters simultaneously so as to minimise a system performance function which is evaluated from a Lyapunov function of the second degree. For the computation of the second degree Lyapunov function a method based on the concept of similarity transformation has been developed and applied so that the simultaneous solution of a large number of algebraic equations can be avoided. To determine the optimum stabilizing signals for a power system, the concept of the Lyapunov function of the optimum system is applied. To compute the Lyapunov function of the optimum nonlinear power system, a general iterative scheme and algorithm have been developed. / Applied Science, Faculty of / Electrical and Computer Engineering, Department of / Graduate

Power system stability study by Szego's method and a maximized Liapunov function

Metwally, Aly Abdel Hameed January 1970 (has links)
In this thesis Liapunov's direct method is applied to transient stability study of power systems. Szego's method is applied to a second order power system in chapter two and a quadratic Liapunov function applied to the same system in chapter three. The hypervolume enclosed by the quadratic V-function is maximized. Changes in the time derivative of the quadratic V function are then made to meet the conditions of Liapunov V and V functions. Finally a maximized modified Liapunov function is constructed from a tentative quadratic function for a three-machine system. / Applied Science, Faculty of / Electrical and Computer Engineering, Department of / Graduate

The stability theory of difference equations using Liapunov's direct method /

Gordon, Sheldon P. January 1969 (has links)
No description available.

Lyapunov-based adaptive methods to servo-control elastic deformations.

January 2014 (has links)
The deformation control problem arises in applications where a mechanical system needs to actively modify the shape of a soft object. This problem is needed in surgical robotics to automate delicate procedures with soft tissues, e.g. suturing and needle insertion, in food industry to automate the shaping of food materials such as dough, or in textile industry to automate the folding and positioning of extensible fabrics, to name a few cases. However, despite the recent progress in physically interactive and soft robotics, the active deformation of compliant objects remains an open research problem with many economically important applications. One of the main issues that complicates the implementation of these types of tasks is the difficulty to identify the deformation properties of soft materials. / The aim of this thesis is to provide model-free solutions to this challenging control design problem. For that, new adaptive methods to servo-control unknown elastic deformations are presented. First, this thesis proposes a kinematic controller that estimates the deformation Jacobian matrix in real-time, hence, avoids the identification of the object’s deformation model. This method computes the unknown matrix based on measurements of the deformation flow and the velocity input to the manipulator; the matrix is then used to map the deformation control action into end-effector velocities. Next, this thesis presents a conceptually different adaptive control approach that does not require to numerically estimate the deformation Jacobian matrix or to numerically compute the optical flow. However, to compute the velocity control input, offline testing deformations must be performed. In this method, the deformation control action is mapped to end-effector velocities by an adaptively varying transposed matrix, thus no matrix inversion is required. / This thesis also tackles the simultaneous vision-based control of multiple elastic deformations. This method incorporates the attitude of a fully-constrained gripper and the measurements from multiple vision sensors into the Jacobian estimation algorithm; by doing this, the number of controllable deformation degrees-of-freedom is increased. Additionally, this thesis addresses the vision-based deformation problem but with torque-controlled manipulators. The presented adaptive method exploits the passivity properties of the system and computes the controller with the online estimated Jacobian matrix. Finally, this thesis formulates the deformation control problem but in terms of force sensory feedback, in other words, the control objective is the regulation of the applied force onto the elastic object; the presented energy shaping controller preserves in closed-loop the Hamiltonian structure of the dynamical system. / The originality of this work lies in the uncalibrated nature of the control methods, i.e. none of the proposed controllers require the identification of the object’s deformation/stiffness model and the camera’s parameters. This uncalibrated feature allows to control on-the-fly elastic deformations of unknown compliant objects. It must be remarked that for each of the control methods, its stability is analysed with Lyapunov theory, and its performance is experimentally verified with robot manipulators. / Navarro Alarcon, David. / Thesis (Ph.D.) Chinese University of Hong Kong, 2014. / Includes bibliographical references (leaves 123-132).

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