| The increase of the harmonic component in asynchronous motor powered by inverter will lead to the aggravation of vibration and noise,however,the inverter power supply is widely used in industry.Accordingly,it is necessary to take appropriate measures to reduce the electromagnetic vibration and noise in asynchronous motor.When variable slot matching and skewed slot degree in rotor are employed in asynchronous motor,the magnetic field that can suppress harmonic is brought in the air gap,which can subsequently reduce the harmonic of electromagnetic force and restrain the electromagnetic vibration.In this thesis,electromagnetic vibration of asynchronous motor under different slot parameters is studied specifically,the contents of which include three parts.Firstly,analytical calculation method is adopted to analyze the electromagnetic force of asynchronous motor with skewed slot in rotor,and the analytical calculation expression of the radial electromagnetic force is inferred.Finite element simulation model is constructed and the simulation is completed by Ansoft.Then,the electromagnetic force of asynchronous motor with variable slot matching is calculated and analyzed.The electromagnetic force spectrums of asynchronous motor with variable slot matching are contrasted,so as to conclude the influence of different slot matching on electromagnetic force.Secondly,the modal calculation of the asynchronous motor is simulated and analyzed.Considering that the radial deformation of the stator is primarily caused by the vibration,then the modal analysis is proceeded with the prerequisite that without taking axial vibration into account.The natural frequency and mode of vibration are gained by simulation and calculation on the basis of modal analysis theory,which provides theoretical reference and foundation for following simulation and analysis on electromagnetic vibration in asynchronous motor.Finally,the ANSYS is employed to calculate and analyze the electromagnetic vibration of asynchronous motor with variable slot matching.Then,the electromagnetic forces calculated in the transient magnetic field are considered as excitation to the surfaces on the stator teeth.And the vibration displacement and vibration acceleration of asynchronous motor with variable slot matching are obtained subsequently.Conclusively,the influences of different slot matching in asynchronous motor on vibration are gained through the analysis on structural vibration simulation results,furthermore,the prototype experiment of three-phase asynchronous motor on vibration is completed to verify the correctness of the simulation results. |
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