To investigate the electromagnetic vibration characteristics of variable-speed pumped storage AC excited machines under the influence of hydro-mechanical-electrical cooperative control strategies

a mo-tor vibration analysis method was proposed based on coupled multi-physics simulations. The electromag-netic vibration behavior of the AC-excited machine under different operating conditions was studied. Firstly

an analytical model of the radial electromagnetic force under rotor-side variable-frequency power supply was established

identifying the main influencing factors of the radial electromagnetic force. Then

taking a 300 MW AC excited machine and its typical hydro-mechanical-electrical coordinated control strategy as an example

the electromagnetic excitation characteristics under power-priority control mode were simulated via field-circuit coupling. It is pointed out that the low-frequency vibration

especially the breathing-mode vibration excited by the interaction of stator and rotor winding belt harmonic fields

con-stitutes the dominant excitation component. Finally

a suppression method for the breathing-mode vibra-tion based on harmonic current injection into the rotor-side converter was proposed. Simulation results show that after harmonic current injection

the maximum vibration acceleration of the low-frequency breathing mode is reduced by 92. 7%

demonstrating the effectiveness of the proposed method.