Fast Evaluation and Suppression of Electromagnetic Vibrations in Interior Permanent Magnet Synchronous Motors Based on Improved Subdivision Subdomain Models

The rapid and accurate calculation of electromagnetic force waves is an essential prerequisite for electromagnetic vibration evaluation and suppression during the initial optimization design stage of the motor. The existing analysis and calculation of electromagnetic force waves and electromagnetic vibrations in interior permanent magnet synchronous motors (IPMSMs) mainly rely on the finite element method (FEM), which is time-consuming and not conducive to the rapid locking of electromagnetic force wave components that play a dominant role in electromagnetic vibrations. Overcoming the shortcomings of existing methods, a fast and accurate calculation method for both radial and tangential electromagnetic force waves in IPMSMs based on improved subdivision subdomain models (SSMs) is proposed, the detailed components and specific source for each component of electromagnetic force waves are quickly locked, and the complex rotor topology and magnetic bridge saturation are accurately considered. Afterwards, the natural frequencies of the stator, taking into account the casing and windings, are quickly and accurately predicted based on the energy method, and the electromagnetic vibrations of the 6-pole and 36-slot IPMSM are quickly calculated and suppressed. Both finite element simulation and prototype test results verify the accuracy of the proposed analytical method (AM) for electromagnetic vibrations in IPMSMs and the effectiveness of using a non-uniform air gap in the rotor to suppress electromagnetic vibrations.