Acoustic Noise Reduction by Reducing Torque Ripple in Traction Machines

This paper discusses on the reduction techniques adopted to reduce torque ripple in an electric machine, which in turn reduces the noise generated within electric machine during driving condition. Source-based noise reduction techniques such as the impact of slot-opening width, use of notches, use of wedges, and its combination are explained with specific design tips. Simulation results show that use of wedges results in 7% reduction in torque ripple when compared with other configurations. In addition to the torque ripple reduction, it also reduces overall system torque. Therefore, additional methods are discussed to increase the system torque and reduce torque ripple by 6%.