An investigation of excitation system interaction

The investigation of excitation system interaction in a two machine infinite bus system is reported. Steady-state stability is studied by means of calculating the eigenvalues from the small displacement system equations. A hybrid computer representation of the system is used to verify the performance predicted by the small displacement analysis and to illustrate the form of the natural mechanical oscillations as well as the mechanical oscillations introduced by the excitation systems. This investigation reveals that the possibility of the interaction of excitation systems should be taken into account when machines are closely tied electrically. Also, in order to portray accurately the dynamic performance during system disturbances such as a system fault, it is necessary to represent the machine and excitation system in detail.