Identification of Coherent Generators in Multi-Machine Power Systems

Identification of coherent generators groups in multi-machine power systems is an important step for both operation and control needs. This paper presents a new identification method based on the generators’ rotor angular positions. The methodology consists of extracting the time-domain dynamic responses of generators to build a relationship matrix indicating the degree of coherency between any pair of generators. Then, by applying the Fuzzy C Mean (FCM) clustering, coherent groups are determined. The Centre of Inertia (COI) is used to represent the coherent group in order to visualize the global oscillations of the rotor angle of that particular group following a disturbance. Applications on the 10-machine New England power system show the feasibility and the validity of the proposed methodology.