Design Of Permanent Magnet Synchronous Motor For New Energy Vehicles Drive Systerm

In today’s human society, the problems of oil resources shortage andenvironmental pollution are very serious. Facing such situation, most countries andcar manufacturers are changing the car power to the direction of new energy, andhave invested a lot to do the research on new energy vehicles. This is undoubtedly thesurest guarantee automotive power, most forward-looking technology roadmap, andat the same time this will also promote the sustainable and healthy development ofthe auto industry. For new energy vehicles, the drive motor is its power corecomponent of the drive system, whose performance directly determines theperformance of the merits of new energy vehicles. With a series of advantages, suchas small iron loss, high efficiency, high power density, high output torque capability,smooth operation, wide speed range, low demand for the controller and so on, andcoupled with China’s rare earth resources in favorable conditions, the permanentmagnet synchronous motor is chosen as the research object of this project.Currently, the design methods of permanent magnet synchronous motor for newenergy vehicle drive system are not mature enough and there are still manybottlenecks in the design process. In this paper, the design and analysis methods atdomestic and foreign of permanent magnet synchronous motor and its main sizeformula are detailed studied and analysed, and based on these, the detailed analysisand design steps of permanent magnet synchronous motor for new energy vehicledrive system are proposed, and the initial value of the main dimensions and all kindsof electromagnetic parameters are obtained.Based on the analytical calculation results and with the help of RMxprtcalculation software and Maxwell electromagnetic finite element analysis software,the initial motor simulation model is established and its associated electromagneticparameters are optimized and two new non-uniform air gap structure rotors aredesigned for the purpose of improving the flux density and the back-EMF waveform.Simulation results show that the motors with the new structure rotors have higher airgap flux density and better sinusoidal back EMF waveform than that of traditionaluniform air gap motor. These performance meet the back-EMF waveformrequirements of the new energy automobile motor drive controller.The performance of the permanent magnet synchronous motors with two newnon-uniform air gap structure rotors are comprehensively simulated with the help ofelectromagnetic finite element analysis software. The results show that these twomotors have high torque output, small torque ripple, small iron loss, high efficiencyand a series of advantages. The simulation results are compared with the test resultsof the permanent magnet synchronous drive motor with advanced and mature technology in today’s international scope. Comparison indicates that theperformances of the motors of this project have reached the performances of theabove-mentioned motor.Finally, the prototype of the motor is manufactured and the test bench is built foranalysis. Through comparing the simulation results with the experimental results, wecan see that the error between measured value and simulation value of the no-loadback EMF is within5%, and its harmonic rate does not exceed5.5%. These resultsindicate that the motor of this project is designed reasonably and can be applied to thenew energy automotive drive system.