Induction motor with an intentionally created saliency for sensorless applications

An analysis of the magnetic behavior of different slot geometries is proposed by means of finite element (FE) software. An intentionally created anisotropy is introduced in the rotor bar geometry, so as to allows a sensorless detection of the IM rotor position. The proposed FE procedure allows to evaluate the sensorless control capability of the IM. The parameters of the induction motor (IM) are determined by means of a FE procedure, based on the d- and q- axis model of the machine. Such a procedure is quite rapid, since is based on the time harmonic response to a high frequency injected signal in the stator winding. This procedure is used to predict the variation of the IM parameters and it results to be useful for both analysis of the IM performance and the design step of the machine. A rotor geometry with an intentionally created magnetic saliency have been analyzed. The rotor prototype is under construction, in order to verify the predicted results.