Analysis of the Steady State Stable Region of an Induction Machine Type of an AC Excited Synchronous Machine

An analysis of the steady state stable region of an AC Excited Synchronous Machine (AESM), especially of that of an induction machine type, is presented in this paper. The AESM essentially has two unstable phenomena, one is the stepout, the other the hunting. The step-out can be judged by the steady state stability condition of a synchronous machine type ; on the other hand the hunting can be judged by that of an induction machine type. The steady state stable region of a synchronous machine type always exists at any slip within the range of 180 degrees of the extended internal displacement angle. However the stable region of an induction machine type is not as simple ; that is, it changes complexly for ships and ceases to exist beyond the range of certain slips (boundary slips). This paper derives these boundary slips and shows by numerical calculations that it is very effective to increase the secondary resistance of an AESM for the expansion of the steady state stable region of an induction machine type