Multi Physical Field Analysis,calculation,and Experimental Research On The Rotor Of High-speed Permanent Magnet Motor

With the rapid development of various industries,environmental pollution and energy consumption have become increasingly serious,making the concept of energy conservation and emission reduction a new requirement for the development of the industry.Because of its small size and high efficiency,high-speed motors are widely used in new energy electric vehicles,flywheel energy storage,suspended blowers and other fields.They are favored by scholars all over the world and have been studied to varying degrees.In this paper,the high-speed permanent magnet air compressor for 27 k W,90000r/min hydrogen fuel cell is studied.The motor rotator is analyzed and calculated by electromagnetic field,temperature field,stress field and other physical fields.The main research contents are as follows:1)The ANASYS Maxwell software is used to check the electromagnetism of the motor,obtain the magnetic flux density distribution of the motor,calculate the core loss of the motor and the eddy current loss of the rotor.The performance of silicon steel sheet is tested,and the effect of two different thickness silicon steel sheets on motor loss is compared and analyzed.This paper calculates and studies the eddy current loss of the high-speed motor rotor through the mechanism of generating the eddy current loss of the motor rotator,compares and studies the eddy current loss of the high-speed motor rotator under two different devices,IGBT and SIC,and comprehensively analyses the contribution of the motor efficiency improvement and loss reduction to energy saving and emission reduction.2)Based on the loss calculation results,the temperature of the motor rotor is studied.Based on the theory of heat conduction in the motor,the cause of temperature rise of the motor is analyzed.The overall temperature distribution of the motor is calculated by motor-CAD software,and the Maxwell 2D and Transient Thermal modules in ANSYS workbench are used for bidirectional coupling calculation to get the temperature distribution cloud of the rotor of the high-speed motor under natural heat dissipation.3)The heat transfer model of the high-speed motor with water cooling system is established.The temperature transformation of the high-speed permanent magnet motor with water cooling system is simulated by ANASYS Fluent software.The effects of different flow velocities of the water channel fluid and different inlet temperatures on the heat transfer of the motor in the water-cooling system are studied.Finally,the validity of the simulation results is verified through experimental tests.4)The strength of the high-speed motor rotor is calculated and studied.To solve the problem that the high-speed motor rotator has a very high rotating speed in rated operation and all parts of the rotator are affected by a large centrifugal force,the assembly between the rotator sheath and the magnetic steel uses the overload fit.By simulation,the stresses at the contact surface between the motor rotator sheath and the magnetic steel,the stresses and strains of the rotator sheath and the magnetic steel are calculated respectively under different excess loads,and the safety margin of the motor operation is obtained.The stress changes of the sheath and the magnet steel of the high-speed motor under different working conditions with 0.16 mm excess of the rotor are simulated and analyzed,which meet the strength requirements.The rotor mode and critical speed of the motor are analyzed to provide the basis for the safe and stable operation of the high-speed motor.