Shaft dynamics in closely coupled identical generators

Previous analyses of shaft dynamic effects have been based on the practice of ´lumping´ identical generators feeding into the same transmission line. This paper investigates the effect on shaft dynamics of the electrical cross coupling between identical generators operating in parallel. It is concluded that the natural frequencies and mode shapes of an arbitrary number of units can be determined from two equivalents. Also the extent to which the shaft modes may be stimulated in feasible on line experiments is predicted.