关键词: 潜水电机, 径向电磁力, 切向电磁力, 振动模态测试

Abstract: To accurately assess the contributions of radial and tangential electromagnetic forces to motor vibration,this paper derives analytical expressions for the air-gap magnetic field of the induction motor as well as the radial and tangential components of the electromagnetic force. These derivations provide a theoretical foundation for setting electromagnetic force loading parameters in subsequent finite element simulations and for validating the accuracy of experimental data,forming a rigorous " theory-simulation-experiment " logical loop. By applying Maxwell ’ s stress theory, the radial and tangential electromagnetic force densities acting on the stator teeth are obtained. The modal vibration modes and frequency
characteristics of the prototype motor are studied through finite element analysis and experimental modal testing. The contributions of radial and tangential electromagnetic force harmonics to the prototype motor's vibration are analyzed through harmonic response simulations and experiments. The study shows that the fundamental and dominant harmonic components of the air-gap flux density and radial electromagnetic force calculated by the proposed model show good agreement with the finite element analysis results, with relative errors less than 9%. Experimental results further validate the accuracy of the model predictions. The proposed approach provides a theoretical basis for the analysis of tangential vibration mechanisms and fault diagnosis in induction motors.

Key words: submersible motor, radial electromagnetic force, tangential electromagnetic force, vibration modal testing