| High speed and high power motor can realize direct drive because it dispenses with the intermediate growth link such as complex gear transmission box,and has significant technical advantages of high power density and high transmission efficiency.It can be widely used in high speed machine tools,high speed centrifuges,flywheel energy storage,aerospace and other important power equipment.But its characteristics of high speed and high frequency also increase the loss and temperature rise of the motor.And the motor is small,heat dissipation is difficult,especially for the maglev motor,the rotor and other parts do not contact,the air gap channel if there is not enough cold air heat will be difficult to lose.The heating temperature rise of the motor will have a certain impact on the resistance value of the winding and the performance of the permanent magnet.Too high temperature may lead to irreversible demagnetization of the permanent magnet and damage of the insulation layer of the winding,thus affecting the stable operation of the motor and the improvement of the motor performance.Therefore,this paper takes the high-speed maglev amorphous motor as the research object.The influence factors of its loss and the distribution characteristics of temperature rise were analyzed.Firstly,the loss of high speed magnetic suspension amorphous motor is analyzed.The loss of each part of the motor during operation is dissipated in the form of heat energy,which becomes the heat source in the main operation process of the motor.In order to accurately distribute the loss distribution of each part,the finite element method was used to analyze the factors affecting the electromagnetic loss and air friction loss of the magnetic suspension amorphous motor,and the distribution of the copper loss,iron loss,eddy current loss and air friction loss of the motor at different speeds were obtained.Secondly,on the basis of heat transfer,combined with copper loss,iron loss,eddy current loss and air friction loss caused by the finite element analysis of the high-speed maglev motor,a mathematical physical model for the coupled temperature field analysis of the motor was established,and the overall temperature rise distribution of the motor was obtained by the method of electromagnetic thermo-fluid coupling.The differences and similarities between the traditional temperature rise analysis method and the multi-field coupling method are compared.Considering the different heat generated under different working conditions,the temperature field distribution and temperature rise law of different working conditions are compared,and the influencing factors of rotor heat dissipation are analyzed.The magnetic suspension amorphous motor experiment platform was built,and the temperature rise of the motor was tested,which verified the accuracy of the thermal analysis method and the effectiveness of the cooling method.Finally,the influence of high temperature environment on electromagnetic performance and operation characteristics of motor is analyzed.Starting from the influence of temperature on the electromagnetic properties of various parts of the motor materials,this paper mainly studies the influence of high temperature environment on the electromagnetic properties of copper winding,permanent magnet and stator materials,thus obtaining the temperature variation rule of radial air gap magnetic density,back potential,flux and inductance of the motor at different operating temperatures,and analyzes the operation characteristics of the motor.The influence of high temperature on the output performance and efficiency of the motor is obtained. |
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