Damping of power system oscillations by excitation control using a current feedback signal

Selective modal analysis combines information in the right as well as the left eigenvectors of the A matrix of a state space description to calculate participation factors of the modes in the state variables. It is shown that these participation factors provide a powerful tool for the evaluation and selection of a supplementary stabilising signal for excitation control. Using these factors, it is shown that a current signal is strongly coupled to the instability modes of hunting and subsynchronous resonance. Power system stabilisers utilising this signal are designed using frequency response methods. The effectiveness of the signal and the control scheme is demonstrated under small and large-scale disturbance conditions on the system.<>