Utilizing generator pair-wise potential energy functions for critical generator estimation

In this paper, a novel method is proposed for identifying the critical generator set following a system disturbance. The proposed method is specifically designed as an enhancement which works in conjunction with single machine equivalent (SIME) methods. The method utilizes an identical set of inputs, and the output yields an estimate of the set of critical generators, a requisite input for applying a SIME approach. The approach utilized proposes a set of generator pair-wise potential energy measures as a quantitative indicator of post-fault system separation. In this manuscript, a derivation is provided justifying the use of the set of pair-wise potential energy measures, since the set is shown to serve as an excellent analog to the total post-fault system potential energy. These pair-wise quantities are subsequently analyzed via the use of spectral graph theory, allowing an estimate of the critical generator set to be extracted from the energy measures. Due to the method´s limited input data requirements, it can be implemented without the need for detailed model information, requiring only measured time-domain data from generator buses. This makes the method an excellent candidate for real-time stability estimation and corrective protection control schemes.