| High-speed motors are widely used in various fields due to their obvious advantages,so the research on them has been one of the hot spots in the international electrical field.However,due to its own characteristics of high speed,high frequency and high power density and so on,it leads to complex field distribution inside the motor and consequently brings more prominent problems.In addition,researchers have studied motor core materials more extensively,and as the main material of motor core,the study of silicon steel sheet is also more extensive and comprehensive.Therefore,this paper starts with the characteristics of the motor itself,and studies the characteristics of the silicon steel sheet for the motor considering the influence of stress.First,a high-speed permanent magnet motor is used as an example to establish its physical model.The Maxwell module in ANSYS is applied to finite element simulation of the electromagnetic field of the motor,and the distribution characteristics of the electromagnetic field inside the motor are obtained by analyzing the characteristic points on the stator and rotor,which include the magnitude of frequency,magnetization mode,and the distribution and existence form of harmonics.The analytical method and Workbench module are applied to analyze the stress field of the motor,and the stress field distribution characteristics under electromagnetic stress and mechanical stress are obtained respectively.Based on the above analysis results,the necessity of considering the stress field in addition to the electromagnetic field in the process of conducting the electromagnetic characteristics of the silicon steel sheet is discussed.Next,the experimental system,equipment principle and experimental process are briefly described.Through experimental measurements on a large number of silicon steel wafers and processing and analysis of the measured data,the electromagnetic properties of silicon steel wafers are obtained for different types,frequencies and stresses,and the changes of the permeability and losses of silicon steel wafers with each physical factor are analyzed to determine the sensitivity of each physical factor to the different electromagnetic properties of silicon steel wafers.Then,a calculation model of permeability considering the coupling of electromagnetic field and stress field was established,which was modified according to the actual permeability,and the accuracy of the model was verified by comparing the simulation results with the calculation results.Through the influence factors of electromagnetic field and stress field,the loss calculation model is improved step by step.By comparing the calculated values of all the improved models with those of the classical loss model,the influence degree of each physical factor and the accuracy of the improved loss model are verified.Finally,the influence of the change that silicon steel sheet characteristics on motor performance is studied.According to the results,design requirements of motors and application occasions,the selection principle of silicon steel sheet is determined,which provides a certain reference for the selection of the silicon steel sheet in the high-speed motor. |
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