Analysis of cogging torque in surface permanent magnet machine with manufacturing tolerances

This paper investigates the production tolerances and variations of the lamination and permanent magnet on the cogging torque of the surface permanent magnet (SPM) machine with mass production. The finite element analysis (FEA) and experiment contrasted analysis method is adopted to deal with the additional component cogging torque, of the 12 slots 10 poles combination SPM machine, caused by production variation of the magnet, stator and rotor lamination. Its reveal that the eccentricity has small effect on the cogging torque, however, the manufacturing tolerances of lamination and inconsistency of permanent magnet have more significant influence on the cogging torque. This paper also propose the method by successively rotating each lamination of stator and rotor to suppress the additional components of the cogging torque.