Analysis of bending and torsional modal of PMSM rotor systems for EV

Abstract

The rotor system is crucial in the all-in-one integrated power system of EV, making the study of its dynamic mechanical performance at high speeds imperative. This paper focuses on analyzing the modal characteristics of EV rotor systems and the impact of individual components on bending and torsional vibrations. Using finite element analysis (FEA), a modal analysis of a 100 kW high-speed electric motor rotor is conducted, followed by experimental tests using an exciting method. Comparing simulation with experimental results reveals how end caps and bearings reduce the rotor’s bending natural frequency (BNF), while the core increases it. Additionally, the addition of rotor components leads to varied reductions in the rotor’s torsional natural frequency (TNF). Furthermore, the error between FEA and experimental values for combined rotor modes remains within 3.53%, affirming the accuracy and reliability of the analysis in predicting rotor modal characteristics.