In this paper, an authentic near-real-time methodology is proposed for locating the sources of FOs using the fundamental frequency of the periodic external driving force based on the direction of the potential energies exchanged between the synchronous generators. First, A directed graph of the network reduced to the generator buses is defined in which the weight and direction of its branches are assigned based on a well-defined energy-driven function. Next, based on the cosine part appearing in the edge weights, subsequent decisions are made, depending on the generators’ angular velocity and active power phases. The proposed algorithm can make a correct and swift diagnosis even under the most challenging operational circumstances, such as resonances and limit cycles. The methodological procedure has been validated on the WECC 3- machine 9-bus and New England 10-machine 39-bus benchmark power systems modeled in the Real-Time Digital Simulator and then analyzed in theMATLAB environment. The simulation results revealed that the presented approach reliably releases all different FOs sources with various kinds of origin.
