Research On Key Technology Of Lightweight High Speed High Power Permanent Magnet Synchronous Motor

High-speed motor has high power density,high efficiency,and small size,which has been widely used in many fields.However,in some special applications,the motor is required to output the limit power in a short time.The design method and ideas of this type of motor are different from the traditional motor,and there are obvious differences in loss and temperature rise from the ordinary high-speed motor.This subject takes two pump motors as the research background and studies the key technologies of lightweight,high-speed,high-power permanent magnet synchronous motors.First,this paper studies the vector diagram of the load operation of the motor,analyzes the reason why the limit power of the permanent magnet synchronous motor cannot be increased,and studies the main factors that limit the ultimate output power of the motor;based on the application requirements of the subject,the high power permanent magnet synchronous motor ultimate output power is completed Calculate and obtains the motor design method under the extreme output power state;establish a full-scale parameterized model of the motor,analyze the influence of the main parameters of the motor on the power density,and finally obtain the design scheme of the motor,and verify it with the finite element simulati on software.Secondly,for the high-frequency time harmonics generated by the PWM converter device in the driver,this article study the influence on the electromagnetic,loss and temperature rise of the motor,and focus on the analysis of each part of the loss.For the copper loss,the skin effect caused by high-frequency harmonics is studied,and its influence on the motor phase resistance is studied.For the iron loss,the harmonic coefficient is introduced to modify the traditional Bertotti-formula,which can be quickly calculated motor iron loss with the consideration of time harmonics;for the rotor eddy current loss,this paper establish a calculation model in the rectangular coordinate system of the motor,calculate the eddy current loss of the permanent magnet and the sheath under the consideration of time and space harmonics;for the electromagnetic torque characteristics of the motor,the effect of time harmonics on the output torque ripple is analyzed.Then,in order to obtain the maximum running time of the motor under the condition of the extreme torque,the transient temperature field of the motor is studied.The simulation model of the motor temperature field is established,the thermal conductivity between each part is calculated,and the tran sient temperature field of the motor is analyzed and calculated,and the temperature rise curves of each part of the motor are obtained;the influence of harmonics and loss coefficient on the temperature field of the motor is analyzed,and the safety of th e motor and the rationality of the design parameters are verified.Finally,based on the previous analysis,the electric pump prototypes are produced,a test platform is built,and the electromagnetic performance test of the motor is completed.According to the test results of the motor's no-load and load performance,the reason for the differences between the calculated value and the experimental result is analyzed,and the performance of the motor in practical applications is verified.