Influence of Slot/Pole Combinations on Torque Ripple in Partitioned Stator Doubly Salient Permanent Magnet Machines

Abstract

The Influence of slot/pole combinations on torque ripple in partitioned stator doubly salient permanent magnet (PS-DSPM) machines are comprehensively investigated. First, the slot/pole combinations for three-phase PS-DSPM machines are discussed. Then, a determination principle of the feasible slot/pole combinations is proposed for obtaining the approximately sinusoidal back-electromotive force (back-EMF) waveform, small cogging torque, and negligible reluctance torque. Furthermore, the unit PS-DSPM machines with proposed 18/5, 18/7, 18/11, 18/13, and 18/17 slot/pole combinations are compared against the conventional 18/12 PS-DSPM machine to verify the effectiveness of the proposed method to determine the slot/pole combinations. The results show that compared with the conventional 18/12 slot/pole combination, the proposed 18/5, 18/7, 18/11, 18/13, and 18/17 slot/pole combinations can significantly decrease torque ripple.