Finite Element Analysis of the Performances of the 3-Phase, 5-Phase, 7-Phase and 9-Phase Squirrel-Cage Induction Motors

Through finite element in time domain models this paper analyses and compares results related the most important performances of four squirrel-cage induction motors, with 3-phase, 5-phase, 7-phase and 9-phase. Quantities characterizing the rated operation and the start-up of the four motors are evaluated and compared. The variation of the magnetic field along the middle circle of the air gap and the time harmonics of the motor’s torque and stator currents are studied.The selection of the best from the four motors, respectively of the correspondent most appropriate multiphase electrical drive with induction motors takes also into account the mean value and the harmonics of the rotor unbalanced force. The influence of the one rotor bar fault is analyzed.