Performance Analysis And Optimization Design Of Soft Magnetic Composite Material Motor

Soft Magnet Composite Material(SMC)is a new type of electrical materials.The fabrication process of soft magnetic composites is different from traditional silicon steel sheet,which is made by stamping iron powder and insulating material.SMC has the characteristics of high resistivity,low eddy current loss and isotropy in electromagnetic characteristics.In order to further explore the electromagnetic characteristics of soft magnetic composite materials and broaden the application range of soft magnetic composite motor,the optimal design and experience of desiging soft magnetic composite motor was summarized.This paper completes the following work and research:Firstly,B-H and B-p curves of soft magnetic composites at different temperatures were measured by ring specimen method and compared with DW470.The measured B-p curves of soft magnetic composites were merged by interpolation to establish the iron loss model with the corresponding frequency varying with temperature.For the unmeasured 300 Hz,500Hz and700 Hz data,the variable coefficient iron loss fitting model was used to fit them.And the temperature change coefficient was introduced to the B-p data at these three frequencies.Secondly,the simulation platform of soft magnetic composite motor in this paper was built by combining Matlab and FEMM.With the iron loss calculation method,the parametric simulation platform was used to divide the stator region of the whole motor,read the magnetic flux density distribution of the corresponding position,and calculate the iron loss of the soft magnetic composite motor more accurately with the orthogonal decomposition iron loss model.According to the calculated loss,Motor CAD was used to calculate and compare the temperature rise of soft magnetic composite motor and DW470 motor at the frequency from 400 Hz to700Hz and analyze the dominant frequency range of temperature rise of soft magnetic composites.The iron loss calculation results of the soft magnetic composite motor were modified according to the temperature rise results and the iron loss model of the soft magnetic composite motor with the temperature coefficient.Finally,orthogonal experimental design and variance analysis were used to analyze the influence degree of five dimensional parameters,stator slot depth,stator tooth width,rotor magnetic separation bridge width,rotor lower slot depth and stator slot width on core loss.The multi-objective particle swarm optimization algorithm was used to optimize the soft magnetic composite motor.The iron and copper loss of the motor were selected as the optimization objective,and the stator tooth width,stator slot depth,rotor outer diameter and stator slot opening of the motor were selected as the input variables to optimize the motor.Pareto solution set was obtained and the optimal solution was obtained.The temperature rise,flux density distribution and air gap flux density of the motor before and after optimization were compared.Based on the optimal solution,the optimal selection range of stator tooth flux density and yoke flux density of the soft magnetic composite motor was summarized.