Fast prediction of variable-speed acoustic noise due to magnetic forces in electrical machines

This paper presents a new multiphysic model and simulation environment for the fast calculation and analysis of acoustic noise and vibration levels due to Maxwell forces in variable-speed rotating electrical machines. In the first part, some numerical methods for the prediction of electromagnetic noise are analyzed and compared to analytical or semi analytical techniques. In the second part, a new coupling of electrical, electromagnetic and vibro-acoustic models based on analytical and semi-analytical modeling techniques is presented. This model is validated by comparing simulation results to experimental results on several electrical machines at variable speed, including surface permanent magnet (SPMSM), interior permanent magnet (IPMSM) and squirrel cage induction machines (SCIM). The main resonances and noise levels are correctly estimated by the models implemented in MANATEE® simulation software, and the calculation time at variable speed varies from one second to a few minutes including harmonics up to 20 kHz.