Experimental verification of torque ripple calculation for induction and synchronous motor

In large capacity motor drives, torque ripple evaluation is important in order to prevent problems such as unexpected lifetime reduction caused by mechanical resonance with the load. However, enormous cost and time are necessary to measure torque ripple in large capacity motor drives. This paper discusses torque ripple calculation methods using electrical signals of a motor and then proposes an accurate calculation method. The experimental results with 400W induction motor and 2.2kW synchronous motor verified that the proposed method can accurately calculate torque ripple caused by harmonics such as inverter voltage distortion and motor spatial harmonics and is useful for torque ripple evaluation.