Dynamic-stability analysis of synchronous machines including damper circuits, automatic voltage regulator and governor

An improved method is presented for the study of the dynamic stability of synchronous generating sets. The complete d- and q-axis machine equations with a.v.r. and governor control loops, linearised for perturbations about a steady-state operating condition, are solved to give the natural frequencies and degree of stability of the various oscillating modes for a single machine connected to an infinite busbar. A 30 MW alternator with multiloop a.v.r. an governor is used to illustrate the use of the method for the study of rotor oscillations and the dynamic-stability limits. The effects of some principal parameters, including those of the machine damper circuits, are examined and important limitations in the accuracy of previous methods of analysis are demonstrated.