Online tracking of sub-transient generator model variables using dynamic phasor measurements

Abstract

In this article, we present a new formulation of the existing synchronous generator models based on phasor measurement data. The proposed sub-transient model allows to estimate the dynamic state variables as well as to calibrate model parameters in real time. This model makes a more efficient use of the information gathered at the multi-functional digital fault recorders (DFRs) and phasor measurement units (PMUs), which are becoming widely available in power grids. In particular, we include in our model the measurements of frequency, rate of change of frequency, and phasor derivatives. Using standard non-linear estimation techniques, we calibrate the inertia constant and generator reactances by considering a synchronous machine with different mechanical power controls. Additionally, we test the performance of this method under multiple power system disturbances such as line-to-ground faults, line loss, load loss, etc.