High-fidelity multiphysics model of a permanent magnet synchronous motor for fault data generation

Abstract

High-fidelity multiphysics model of a permanent magnet synchronous motor for fault data generation Hyunseung Lee Dept. of Mechanical Convergence Engineering Graduate School of Hanyang University This study proposes a high-fidelity multiphysics model of a permanent magnet synchronous motor (PMSM) for generating virtual fault data. The proposed model helps to overcome the challenges encountered in real-world applications of data- driven prognostics and health management, where such data is often limited. To achieve this goal, i.e., generating high fidelity vibration data at a fault condition of a PMSM, the proposed model efficiently incorporates several multiphysics characteristics of a PMSM. First, a simple yet effective two-dimensional electromagnetic model is proposed to calculate electromagnetic force, which consistently induces vibrations in the PMSM during operation with the actual PMSM driving measurements, including current and rotor position. Next, the contact force within the bearing is obtained solving analytical equations based on a rolling element bearing theory, enabling the representation of the force variation at the spall fault on the outer race. The rotor dynamic model is also constructed to predict the rotor response considering electromagnetic and unbalance effects. Finally, an effective modeling method for the three-dimensional PMSM structure is introduced, which is capable of generating vibration response on its surface when the electromagnetic force, bearing contact force, and rotor’s reaction force are imposed to the PMSM. The physical properties of the proposed model are estimated through extensive torque experiments and modal tests. The vibration data generated by the proposed model is validated through actual vibration experiments, confirming the high-fidelity nature of the proposed model. The proposed model not only overcomes the limitation of data-driven diagnosis methods, which often lack sufficient data, but also provides a design enabling solution. As a result, the proposed high-fidelity model makes a significant contribution to the field of data- driven fault diagnosis for electric motors, offering reliable and predictive insights into bearing and rotor failures. Keywords: Fault diagnosis, Digital twin, Finite element analysis, Permanent magnet synchronous motor, Vibration analysis