Online coherency identification based on correlation characteristics of generator rotor angles

In this paper, a new approach for recognizing coherent groups of generators based on the correlation characteristics of generator rotor angle oscillation is proposed. In this approach, by online measuring generators rotor angle oscillations, the correlation coefficients between all pairs of generators are evaluated. Based on the evaluated correlation coefficients, coherent groups of generators are identified. Comparing the result with time domain transient stability simulation following a disturbance and also modal analysis, leads to similar coherent groups. The proposed approach is demonstrated on the IEEE 39-bus system with promising results.