Theoretical and Experimental Analysis of Operating Point Stability of Synchronous Machines

A stability study of synchronous machine operation is made by applying Routh´s criterion to the linearized equations describing behavior for small perturbations about a steady state operating point. Two special cases for non salient-pole machines are examined and experimental confirmation of the predicted stability boundaries is given. Salient pole machines with both d and q-axis damper windings are also investigated. Results illustrating the effect of frequency, load torque, rotor inertia, stator resistance, and other machine parameters and constraints are included and suggestions regarding improved performance are given.