Research On Iron Loss And Temperature Rise Of High-Speed Amorphous Alloy Permanent Magnet Motor

The high speed permanent magnet motor(HSPMM)has the advantages of high efficiency,high power density,direct drive high speed load and so on,and has been widely used in electric vehicles,high-speed motorized spindles,aviation,aerospace and micro gas power generation and other fields.However,the high speed permanent magnet motor has the disadvantages of high specific loss,small heat dissipation area,and difficulty in heat dissipation of the motor,which may cause rotor overheating and lead to irreversible demagnetization of the permanent magnet,it is not conducive to the reliable operation of the motor.So it is very important to study the loss and temperature rise of high speed permanent magnet motor.Because the iron loss is very high in the high-speed motor,therefore the amorphous alloy with low loss is used as the stator core material of the high speed motor.This paper take iron loss and temperature rise of high speed amorphous alloy permanent magnet motor as the research object,and the influencing factors of iron loss and temperature rise are studied and verified by experiments.Firstly,the loss curves of amorphous alloy stator core under different frequencies are measured by experiments,and then this paper based on the finite element software to calculate sine wave power supply no-load iron loss under different frequency,different rotor magnetic pole structure and different slot-pole match respectively.The fitting relationship between the motor frequency and no-load iron loss is obtained,the no-load iron loss under the power supply of inverter is calculated and the accuracy of the calculation results is verified by no-load iron loss test of high speed amorphous alloy permanent magnet motor.Secondly,on the basis of fluid-solid coupling,comparing and analyzing the thermal influence of winding end equivalent and motor encapsulating for the high speed permanent magnet motor and the effect of different thermal conductivity for conductive adhesive on the motor temperature rise is studied.The effect of rotor surface roughness,motor speed,motor slotting or not on the stator and rotor heat transfer is being calculated,and the fitting relationship between air friction loss and rotor surface roughness,motor speed is obtained.The influence of different cooling boundary conditions on the heat dissipation of the motor is analyzed.Finally,the finite volume method is used to simulate the coupling between the fluid field and the temperature field in the different rotor structures for the water-cooling totally enclosed high speed permanent magnet motor.The air turbulence effect is been enhanced and the cooling conditions is been improved through open axial vents in rotor and join wafter at rotor end,and the influence of different rotor holes number and rotor hole size on the motor fluid field and temperature field is studied.The restraining measure of the temperature rise of the permanent magnet can be used as reference for the totally enclosed high speed permanent magnet motor with similar structure.At last,the temperature rise test of 15 kW totally enclosed water-cooling high speed amorphous alloy permanent magnet motor is carried out,and the test data is compared with the calculation results,which validates the correctness of the solution method of coupled field.