Analysis And Research On The Critical Magnetic And Thermal Characteristics Of High Speed Induction Motor

As the industrial technology keep on development,there is an increasing demand for high speed drive system in the field of transportation,pipeline transportation,manufacturing and other fields.The traditional high speed drive system mostly uses the ordinary induction motor to drive gear box to achieve the high speed output,but it will bring friction loss,noise,low efficiency,poor reliability and other shortcomings.With the development of power electronic technology becomes more mature.The new high speed direct drive system can solve these problems very well.High speed direct drive system is that high speed motor directly connects load and achieve high speed output.As the main type of high speed motor,high speed induction motor has higher power frequency and higher rotor speed than ordinary induction motor.So the high speed motor is very different from the conventional motor in the design.In this paper,the problems of magnetic field and temperature field of high speed induction motor design are analyzed.Firstly,the selection of the main dimensions,the design of the rotor structure,the selection of core material and the calculation of the loss in the design of high-speed induction motors are introduced.The selection of electromagnetic load of high speed induction motor is analyzed by equation of motor main dimensions.The characteristics of three different rotor structure,laminated rotor,solid smooth rotor and solid slitted rotor are compared.The commonly used core materials in high speed induction motor are introduced.Three calculation methods of high speed induction motor core loss are analyzed,and the formula of high speed induction wind friction loss is given.Secondly,Referring to the electromagnetic design program of the common induction motor,and combining the design features of the high-speed induction motor,the electromagnetic design program of the high speed induction motor,the laminated rotor structure and the solid rotor structure are programmed respectivelyby using the programming software.The GUI interface is added to the program to facilitate data entry and calculation results display.Thirdly,the selection of the rotor structure of the high speed induction motor is analyzed.The performance of three kinds of motors,which are laminated rotor,solid smooth rotor and solid slitted rotor,is analyzed by using the eddy current finite element method(FEM).In view of the high speed induction motor with solid slitted rotor structure,the influence of slit size and slit number on motor performance is analyzed by comparing various slitted size schemes and different slit number schemes.Finally,the solid slitted rotor is taken as an example to establish the three dimensional temperature field models.The heat source of motor is set according to the calculation results of the eddy current loss.The temperature field distribution of the high speed induction motor is analyzed by the finite volume method.The temperature distribution laws of rotor core,stator core and stator winding are obtained.