INFLUENCE OF ROTOR WINDING CONSTRUCTION OF MULTIPHASE INDUCTION MACHINE ON THE SURFACE LOSSES

This paper analyses the influence of construction of rotor winding of multiphase induction machine on the rotor harmonic losses. These include additional surface losses in the rotor bars and core caused by higher spatial harmonics of the stator magnetomotive force. Significant values of these losses can lead to local overheating and indicate an increased value of torque ripple; it is therefore of interest to limit their value. This can be achieved by an adequate selection of the number and shape of the rotor rods. In the paper, the influence of rotor winding construction on the additional surface losses is examined. A number of different stator winding topologies with different stator current waveforms is included in the analysis. Finite element analysis is conducted to obtain precise calculation of field distribution and losses for individual spatial harmonics. Based on the obtained results, suitable combinations of stator winding distribution and rotor design are identified. The results of this analysis and the developed software solution for the calculation of surface losses can be of great use in the process of designing multiphase electric machines