A novel suppression method of 6th-order torque ripple of permanent magnet synchronous motor without torque meter

The authors have proposed a new suppression method of the 6th-order torque ripple of permanent magnet synchronous motors (PMSMs). The proposed method can estimate the harmonic components in the flux-linkage which is the cause of 6th-order torque ripple. And, the proposed method does not use a torque meter, and estimate the harmonic components by mainly using current sensors of the inverter. By simulation using two RT models, it was confirmed that the 6th-order torque ripple could be suppressed approximately 48%.