Accuracy of a Reduced Order Model of Induction Machines in Dynamic Stability Studies

Previously published information regarding the accuracy of the eigenvalues calculated from the linearized reduced order model of an induction machine, wherein stator transients are neglected, is shown to be incorrect, nearly opposite to the actual situation. In this paper the error in the previous work is pointed out and the parameters of the induction machine which influence the accuracy of the linearized reduced order model are established analytically. A ratio of parameters is suggested which could be used as an indication of the accuracy of the reduced order model. A salient conclusion is that the accuracy of the linearized reduced order model increases as the horsepower rating of the machine increases. This conclusion is completely opposite to that previously reported.