Power system stability assessment based on synchronized phasor measurements

Abstract

An approach to design power system steady state estimation and transient stability assessment using a multi-machine area network based on multiple synchronized phasors measurements is presented. The oscillations were analyzed from measured synchronized phasors in a multi-machine two area network. The fast Fourier transform (FFT) filter was used to extract the desired frequency from the angular frequency estimated by measured synchronized phasors. The dynamic characteristics of the system were linearly approximated with a set of differential equations from which the appropriate eigenvalues were identified for the dominant mode. In transient stability analysis, direct methods were used to derive the rotor angles from generator parameters; phasor voltages and currents. The least square method was used to estimate the power-delta curve from the calculated variables based on the time domain. A disturbance scenario was analyzed and the critical stability region of the power system determined with the equal area criterion. The algorithms developed were tested on a four-machine two area system by simulation of disturbance scenario on the network.