MODEL ORDER REDUCTION IN FREQUENCY DOMAIN AND ITS APPLICATIONS

Abstract

The work included in this thesis deals with model reduction techniques in frequency domain i.e. based on a transfer function description of the original system. The first chapter introduces model reduction problem, its necessity and a broad classification of various model reduction techniques. Reduction by Cauer forms, Routh-Hurwitz array, the Integral square error methods are described in chapter-2. The method to obtain step response of a system is presented in chapter-3. The respective step response of the illustrative examples are shown for comparision purpose. A scheme to design controllers, using reduced order models obtained from Cauer forms method, is given in chapter-4. The computer programs, in FORTRAN, for I model reduction , step response and Nyquist plot, have also been developed and implemented successfully on a PC.