Studies on damping of electromechanical oscillations in multimachine systems with longitudinal structure

Power systems with longitudinal structure may be subjected to poorly damped oscillations at low frequencies; the structure of speed governors and of excitation controls may have a considerable influence on damping of these oscillations. The strong influence of generator position on damping efficiency is analyzed, as are the effects of load location and load characteristics on the damping improvement that may be expected from additional feedback in excitation control. Some schematizations make it possible to obtain a qualitative insight into the influence of different parameters on oscillation damping. An example of slow oscillation damping in the Italian system is given.