Research On The Critical Magnetic And Thermal Characteristics Of Strip Winding Permanent Magnet Synchronous Motor

The strip winding permanent magnet synchronous motor has outstanding advantages such as high slot full ratio,good performance of heat radiation and compact winding end structure.It has become one of the research hotspots in the field of new energy vehicles.However,due to the inherent structural characteristics of permanent magnet motors,cogging torque limits the development of permanent magnet synchronous motors with strip windings.Excessive cogging torque will cause the motor to vibrate and affect the stable operation of the motor.In addition,high-frequency currents will produce large AC losses in the flat copper wire windings,which will cause the motor’s temperature rise to be too large,and in severe cases,it will cause the motor to produce permanent failures.In this paper,taking a50 k W strip winding permanent magnet synchronous motor as an example,the cogging torque,loss calculation and temperature rise of the motor are studied.Aiming at the problem of the torque fluctuation of the strip winding permanent magnet synchronous motor caused by the cogging torque,based on the energy method and the Fourier series theory,the analytical expression of the cogging torque is analyzed and deduced,and combined with the unique situation of the strip winding permanent magnet motors,finite element simulation is used to analyze the strip winding permanent magnet synchronous motors with different stator slot types,slot wedge thickness,slot width,slot height and the ratio of slot height to slot width,and study the influence of different stators parameters on the cogging torque and torque ripple of the motor.Analyze the loss of the strip winding permanent magnet synchronous motor,and use the finite element analysis model to calculate the core loss,copper loss and eddy current loss of the motor when the ratio of the slot height to the slot width of the rectangular open slot and the rectangular half-open slot is different,and the influence of different stator structures on the various losses of the motor is analyzed.Establish the temperature simulation calculation model of the strip winding permanent magnet synchronous motor with two stator structures of rectangular open slot and rectangular half-open slot,and set the heat source according to the motor losses calculated by the two-dimensional transient field,and use the finite volume method to calculate the temperature.The temperature rise of the motor models with different stator structures is calculated,and the temperature distribution of the strip winding permanent magnet synchronous motor under different stator structures is revealed.