Experimental Verification and Electromagnetic Analysis for Performance of Interior PM Motor According to Slot/Pole Number Combination

This paper reports on the experimental study on and analysis of the influence that the number of stator slots has on the performance of an interior PM (IPM) motor. First, for a conventional 6-pole IPM rotor, stators with 18, 27, and 36 slots that satisfy the same required and restricted conditions are designed. Next, the performances and parameters of each IPM motor, such as cogging torque, torque ripple, d- and q- axis inductance, and total harmonic distortion (THD) of back-EMF, are investigated using 2-D finite element analysis (FEA). Finally, test results for factors such as the d- and q-axis inductance, back-EMF, and cogging torque measurements are obtained to confirm the analysis results. From the results obtained in this work, it is concluded that the influence of the number of stator slots on IPM motor performance is quite significant.