| With the rapid development of electric vehicles,assisted driving,autonomous driving and other technologies have gradually become a research hotspot.As one of the realization conditions of the auxiliary driving system,the laser scanning radar should have the characteristics of high measurement accuracy,fast response,and not be affected by clutter.Compared with other drive motors,Integer slot distributed winding hysteresis machine(ISDW-HM)has high speed,low torque ripple,simple control system and reliable operation.It is widely used in scanning imaging,medical titanium alloy template,laser printing and other fields.The main disadvantage of this kind of motor is its low efficiency and power factor.In addition,under the background of high-precision application,the air gap density of armature magnetic field(AMF)still contains a large proportion of high-order harmonic components,which often leads to greater motor noise and electromagnetic loss.Based on the principle of magnetic field modulation,The air-gap flux density of AMF and permanent magnet field of the 18-slot 2-pole ISDW-HM are analyzed theoretically,and on this basis,a low harmonic design method based on unequal turns winding is proposed.Forming the topology of the 18-slot/2-pole Unequal turns concentric winding hysteresis machine(UTCW-HM),Detailed research is carried out on its working principle,air gap magnetic density composition,harmonic weakening theory,dimensional structure design,electromagnetic performance simulation and experimental testing:Firstly,the structure and working principle of hysteresis motor are introduced in detail.Based on the basic theoretical knowledge of ISDW,the magnetomotive force(MMF)of single-phase winding and three-phase winding is analyzed.The MMF permeance model of 18-slot/2-pole ISDW-HM is established by the equivalent magnetic circuit method,and the air-gap flux density of AMF and hysteresis magnetic field and its harmonic formula are derived.Moreover,the finite element simulation software Maxwell was adopted for modeling and simulation,which verified the accuracy and rationality of the theoretical derivation and to lay the groundwork for the following low harmonic design.Secondly,based on ISDW-HM,a low harmonic design scheme of unequal turns winding is proposed.The 18-slot/2-pole UTCW-HM model is established by finite element software,and its design steps and harmonic attenuation principle are explained and verified.The main parameters of the motor are optimized,and the structure size of UTCW-HM is finally obtained.Thirdly,the improved Preisach hysteresis model was applied to UTCW-HM,and the related electromagnetic properties of 18-slot/2-pole UTCW-HM were simulated by finite element software,including the air-gap flux density of AMF,permanent magnet linkage,no-load induced electromotive force,starting torque,output torque and inductance.The results were compared with 18-slot/2-pole ISDW-HM.Then,the losses of the two motors were calculated,including stator core loss,armature winding copper loss and hysteresis alloy eddy current loss,and combined with each loss and output power to get the efficiency of the two motors.Finally,a prototype was fabricated according to the size parameters of 18-slot2-pole UTCW-HM,and a semi-physical experimental platform based on RTU-BOX was constructed.The prototype was tested,and the test results were compared with the simulation results to verify the performance of the prototype. |
PDF Full Text Request