Research On Electromagnetic And Vibration Characteristics Of High Speed Switched Reluctance Motor With Amorphous Alloy Core

Compared with permanent magnet motors,SRM has obvious advantages in peak speed capacity,reliability,cost and other aspects,and is one of the first choices of medium-high speed drive motors for electric vehicles.However,the efficiency of traditional switched reluctance motor is relatively low.In order to solve this problem,this thesis uses amorphous alloy instead of traditional silicon steel.However,the amorphous alloy materials also brings about other problems,including:(1)it is difficult to process amorphous alloy stator cores into complex shapes,and the forming process has a great impact on the electromagnetic and mechanical properties of materials and the performance of motors;(2)the vibration problem is common in SRM,and the impact of the introduction of amorphous alloy materials on this problem needs to be evaluated.Aiming at the problems above,this thesis focuses on the research of electromagnetic and vibration characteristics of high-speed switched reluctance motor using amorphous alloy cores(HSSRMA).The main research work includes the following aspects:Firstly,in view of the influence of forming process on the amorphous alloy core properties,a series of core samples was designed and made.The B-H curve and iron loss curve of amorphous alloy cores under different overlying coefficient,different annealing processes and different working frequency were measured.Based on the test results and the design principles of traditional high-speed switched reluctance motor,the electromagnetic design scheme for high efficiency and high performance HSSRMA was studied and proposed.It is compared with the conventional silicon steel high speed switched reluctance motor.Secondly,the electromagnetic excitation source problem in HSSRMA was studied.Based on the air gap permeance and the of maxwell tensor method,the radial and tangential electromagnetic force wave under different currents were analyzed theoretically.And the mathematical relationship between the tangential electromagnetic wave and torque was also deduced.The electromagnetic field model of HSSRMA was established.The tangential and radial electromagnetic force waves under different currents were compared through finite element simulation,which verify the theoretical analysis method.Thirdly,the precise modeling of stator structure of HSSRMA was studied.And its natural modal frequency is analyzed.Combined with the modal experiment of the stator core of the prototype,the analysis,simulation and experimental results of stator modal frequency were compared and analyzed.Based on the stator structure field model,the influence of the materials such as casing and core,the cooling bars and water channels on the modal frequency of the stator system of the HSSRMA was studied,and the optimal design method of the structure of the motor was obtained.Finally,the electromagnetic excitation source was added into stator structure using the harmonic response analysis to calculate the vibration of HSSRMA.The motor vibration characteristics under different currents were compared,and current optimization method is put forward from the angle of vibration suppression.Based on the electromagnetic vibration simulation model,this thesis compares the differences between the HSSRMA and the traditional silicon steel high-speed switched reluctance motor in excitation source characteristics,stator modal frequency,magnetostrictive coefficient and vibration characteristics,so as to analyze the disadvantages of the amorphous alloy high-speed switched reluctance motor in vibration.