Research On Stator Loss And Temperature Rise Prediction Of High Speed Permanent Magnet Motor Based On Magneto Thermal Coupling

High speed permanent magnet motor(HSPMM)is commonly used in fuel cell,aerospace,flywheel energy storage and other industrial applications because of its small size and high power density.Due to the special characteristics of HSPMM,key technologies and design methods different from those of ordinary motors are required to achieve its excellent performance.Therefore,this paper analyzes and studies a 22 k W,90,000r/min HSPMM,focusing on four technical aspects: electromagnetic design,loss calculation,temperature rise analysis and cooling optimization of the HSPMM.The specific work is as follows:First,according to the characteristics of high-speed motor,complete the design of stator and rotor structure,including stator core material,winding distribution,rotor material,shape,insulation,etc.After determining the stator and rotor structures,the main dimensional parameters of the motor are calculated in combination with its technical indexes such as speed,power and torque.The calculated parameters are input into the finite element simulation software,and the output power,efficiency,torque,current and other parameters of the motor are simulated by establishing a two-dimensional finite element simulation model,and the corresponding motor characteristic curves are obtained.According to the simulation results,the rationality of the design content is verified.Secondly,loss calculations were performed for this HSPMM,considering that rotational magnetization and magnetic field harmonics are more complex and there are interactions between high frequency and temperature on motor iron losses.In order to obtain an accurate HSPMM iron loss calculation model,different iron loss models are proposed,and a stator core loss model considering these physical factors is proposed by considering the interaction.The rotor wind-motion loss,winding loss and rotor eddy current loss are also analyzed and calculated.Further,Then,the three-dimensional temperature field model of the motor is established,the solution domain and boundary conditions are set,the heat dissipation coefficient of each part is found,and the temperature rise distribution of the motor is finally obtained.After that,considering that the material properties of the motor change with the temperature,the magnetic thermal coupling(MTC)method is applied to model the motor,and the temperature distribution is closer to the actual situation after experimental verification.Finally,based on the results of temperature field calculations,the effects of different flow rates and different cross-sections of the coolant in the cooling pipes on the cooling effect of the motor are further analyzed to obtain the optimal results,and relevant design suggestions are made in order to provide more references for the cooling system design of HSPMM.