Identification of system wide disturbances using synchronized phasor data and ellipsoid method

With phasor measurement units (PMU) installed in power systems, synchronized measurements are now available in real time. These global measurements can be utilized to develop real time visualization and system monitoring tools. The characteristic ellipsoid (or minimum volume enclosing ellipsoid (MVEE)) method is one such recently proposed tool for identification of system disturbances.This paper examines: (i) the effectiveness of different input signals and (ii) the attributes (volume, orientation and position) of the ellipsoid that are most sensitive in detecting a system wide disturbance. Specifically, we consider two Eastern interconnection events namely: (a) a frequency deviation event arising from a substantial loss of generation and (b) an angle deviation transient. Real time system wide PMU data corresponding to (i) bus frequencies (ii) voltage magnitudes and (iii) phase angles are considered as inputs to the MVEE algorithm and the sensitivities of the ellipsoid attributes are studied for these inputs for the two disturbances. From the study, the most appropriate (input signal, attribute) pair is identified to detect a given system disturbance. This preliminary study can be potentially useful in designing a dashboard to enhance real-time wide area situational awareness of the power grid.