Relative Dymamic Stability of a One-machine System : Frequency-response Approach

Abstract

A one-machine system under small perturbations was represented in a closed-loop block diagram and its open-loop transfer function was calculated. The concept of relative stability was developed by means of a generalized Nyquist's criterion. Moreover, the indicial response of terminal voltage according to the unit step change of excitation voltage was calculated by means of a Fourier series approximation and its integral squared error was proposed as a measure of relative stability. A stability analysis using this measure was developed for various values of power output. Also, the effects of the regulator gain were analyzed using this measure.