Fast Coherent Area-Based Phasor Measurement Unit Placement for Power System Dynamic Vulnerability Assessment via Hierarchical Clustering

Abstract

Phasor Measurement Unit (PMU) is one of the most important components of Wide Area Measurement System (WAMS) as the measurement device. However, since the PMU cost is still expensive, its location must be optimally determined. This paper proposes the optimal PMU placement scheme for the dynamic vulnerability assessment evaluating the Center-of-Inertia (COI) based frequency in fast coherent areas, identified by a novel Hierarchal Clustering (HC) method called HC-max which evaluates the clustering result via point biserial correlation coefficient. HC-max is superior in terms of clustering precision and less parameter compared to nonhierarchical clustering. After determination of fast coherent areas, PMUs are optimally placed via evaluation function which minimizes the COI based area frequency estimation error by bus frequency. The results show that the placed PMU can well estimate the COI based area frequency and detect the area out of step signature.