Estimating power flow conditioning from phasor measurement data

Electric power systems can display a range of undesirable dynamic phenomena by which acceptable, stable operation may be lost; among these is the “voltage instability” phenomena. Formal analyses in smooth models classify voltage instability as a bifurcation phenomena. Ill-conditioning of the power flow, reflected in high sensitivity of bus voltage magnitudes to load variation is an often observed precursor to voltage instability. Motivated by this insight, this work will propose a conditioning monitor based solely on phasor measurement unit (PMU) data, without need for network parameters or topology to construct the power flow model, and hence suitable for near-real-time implementation. As an initial proof of concept in computational test systems (for which complete power flow data is available), we will demonstrate that the proposed measure closely tracks the largest singular value of the inverse of the power flow Jacobian.