Comparative Study of Various Slot Pitch for 2-Pole 6-Slot Ultra-High Speed Permanent Magnet Synchronous Motor

초록

The 2-pole 6-slot permanent magnet synchronous motor (PMSM) is an attractive option for ultra-high-speed (UHS) applications due to their high manufacturability and balanced magnetic force. UHS PMSM should be designed with short stack length and end coil height due to rotor dynamics issue. Also, due to its high frequency, it must be designed considering stator iron loss, rotor eddy current loss, and AC copper loss. With the same pole-slot combination, the performance varies greatly depending on the slot pitch, so we compared the efficiency and power density of the 2-pole 6-slot UHS PMSM according to the winding arrangement. For a reasonable comparison, an optimal design was performed for each slot pitch, and to reduce computation time, the optimization was conducted in two stages: axial size minimization and efficiency maximization. It was confirmed that in terms of total axial length, 1-coil pitch was the shortest due to the advantage of short end coil height, even with the lowest winding factor. On the other hand, 2-coil pitch has good trade-off relationship in terms of efficiency and axial size.

키워드