Torque Ripple Analysis and Reduction of Permanent Magnet Synchronous Motor

Torque ripple of vector-controlled permanent magnet synchronous motor(PMSM) is analyzed from the inverter viewpoint, with the use of flux linkage formula, stator flux linkage locus is calculated respectively in view of space vector pulse width modulation(SVPWM) and dead-time effect. Torque ripple quantity is calculated caused by the aberration of flux linkage vector, it's relationship with output frequency and carrier frequency is analyzed. Torque ripple characteristics are obtained, based on which, reduction methods are proposed. There is confliction between the two ripple reductions in carrier frequency, several factors in integrative reducing torque ripple are presented. The proposed methods have application value for torque ripple reduction and carrier frequency selection of the inverter.