Today's induction machines, intensively electrical, magnetic and mechanically stressed, must have high steady state and dynamic performances. In these conditions, only the steady state design of a small power induction motor, even with definite destination, proves totally unsatisfactory, because dynamical operation, practically inevitable, cannot be anticipated. A simultaneous optimal steady state and dynamic design, is mandatory. With this aim, the paper summary presents theoretical bases of dynamic mathematical models and also the results of some representative simulations.