Parameter estimation for induction motors to study the effects of voltage, frequency and slip

Parameter estimation for cage-induction machines is studied by means of 2D finite-element (FE) computations. The estimation methods are based on the time-harmonic and time-stepping FE analyses. The parameters are estimated in a wide operation range. The main purpose of the paper is to study how the steady-state and small-signal parameters vary in the case of a cage-induction machine designed for a frequency converter supply. The estimation is performed at 13 different supply frequencies. At every frequency, several flux levels are studied. Slips that provide the best efficiency are looked for and the parameters are estimated at these points. For comparison, the parameters of a typical grid-supplied cage-induction machine are also estimated at several slips and flux levels.