<p>Permanent magnet synchronous motors (PMSMs) are typical electromechanical energy-conversion systems, in which the electrical and mechanical subsystems interact and impact each other. However, existing studies have investigated these two subsystems independently and failed to determine the coupling effect between electrical signals and mechanical vibrations. To address these gaps, a comprehensive electromechanical coupled model is proposed herein. This model integrates the PMSM model based on the winding function and the rotor-bearing dynamics model. The developed model can take into account the variations in inductance and current caused by non-uniform air-gap distribution. The electromechanical dynamic responses of the PMSM under rotor-bearing vibration and rotor eccentricity conditions are systematically analysed using this model. Results demonstrate that the proposed model improved the accuracy of both internal and external excitation representation in PMSMs compared with the conventional models. The dynamic behaviour of the rotor-bearing system is distinctly reflected in the electrical signals, and the variation laws of rotor eccentric distance and eccentric angle on the dynamic characteristics of the PMSM are revealed. The proposed model provides theoretical support for investigating the electromechanical coupled effect in PMSMs and offers an effective approach for state detection and fault diagnosis of motor-driven systems.</p>