Rotor Speed-Free Estimation of the Frequency of the Center of Inertia

Abstract

This letter proposes a formula to estimate the frequency of the center of inertia based exclusively on measures of bus frequencies, obtained, for example, from phasor measurement units; the network admittance matrix; and two paraemters of synchronous generators, namely, the inertia constant and the internal reactance. The proposed formula can be utilzed on-line and requires a highly reduced set of measures of bus frequencies. The letter discusses the theoretical background of the proposed expression and tests it with a 1,479-bus model of the all-island Irish transmission system.