Characteristic Analysis And Optimization Of Linear Vernier Motor With U-type Permanent Magnet

As the urban population continues to increase,the floor heights are hitting new highs,so the requirements for elevators are even more demanding.The linear motor-driven cordless elevator system has the advantages of unlimited lifting height and running speed,realizing multi-car cyclic operation,saving building space,and improving carrying efficiency.Therefore,direct-drive elevators have broad application prospects.Since the implementation is cordless,the thrust density of the permanent magnet linear motor needs to be further improved.Considering reducing cost and improving thrust density,this paper proposes a U-shaped Linear Vernier Permanent Magnet(U-LVPM)motor,analyzes its working mechanism and topology,and studies its electromagnetic design and characteristic analysis,multi-objective optimization,and key theoretical and technical issues such as temperature fields.This paper mainly conducts research in the following aspects:A new topology of U-shaped magnetic pole permanent magnet linear vernier motor is proposed.The structural characteristics and working mechanism of the new motor are analyzed.The motor has the advantages of small flux leakage and high thrust density,and the design of key parameters is carried out.Study the electromagnetic characteristics of U-LVPM motor.The finite element model of U-LVPM motor was established.Based on the same electrical load,magnetic load and the same amount of permanent magnets,a Halbach shaped Linear Vernier Permanent Magnet(H-LVPM)motor was established.The no-load magnetic field distribution and no-load back EMF of the two motors are analyzed;the performance parameters such as thrust density,inductance,and positioning force of the two motors are compared.The results show that the U-LVPM motor has the advantages of higher thrust density,higher no-load back EMF,and larger thrust-to-weight ratio than the H-LVPM motor.Multi-objective optimization design of U-LVPM motor.In order to improve the thrust density,force energy index,reduce thrust fluctuation and iron loss as the optimization goals,the secondary tooth height,the secondary tooth pole arc coefficient and the size of the primary permanent magnet are selected as the optimization variables,and the optimal design model is established.The Taguchi method is used for the optimization design,and the experimental matrix is established according to the influence factor levels of each optimization variable;the orthogonal experiment is carried out by the finite element method,and the variance and proportion of the optimization variables to the optimization target are calculated,and the optimal comprehensive performance of the U-LVPM motor is obtained.parameter combination;compare motor performance indicators previous and Optimized.The results show that the performance of the motor is significantly improved after multi-objective optimization.U-LVPM motor temperature field analysis.Using the finite element method,a temperature field analysis model is established.First,the heat source density is calculated from the loss of each part of the motor,and then the thermal conductivity,heat dissipation coefficient and air gap convection heat transfer coefficient of each part of the motor are calculated.Finally,a U-shaped permanent magnet linear vernier motor is established.The temperature field model of the U-LVPM motor is analyzed,and the temperature distribution of each part of the U-LVPM motor is analyzed.48 figures,17 tables,and 79 references.