PMU based power system stability analysis

Abstract

Power system steady state estimation and transient stability is analyzed on a multi-machines network based on multiple synchronized phasors measurements. The oscillations were analyzed from a four machine network and a large power system by using the Fast Fourier Transform (FFT) filter 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. 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. Transient Stability was analyzed through a disturbance scenario and the critical stability region of the power system was determined with the equal area criterion. The algorithms developed were tested on a four-machine two area system and a large power system by simulation of disturbance scenario on the networks.