【作者】 李娜；

【导师】 王晓远； 张勇；

【作者基本信息】 天津大学 ， 电气工程， 2019， 硕士

【摘要】 在全球环境问题和能源危机的背景下,国务院针对汽车行业颁布《中国制造2025》,对汽车的油耗提出严格的要求。微混合动力汽车凭借其对传统汽车改动小、成本低、易批量化生产、节能减排等优点具有很好的应用前景和研究价值。本文将对微混合皮带驱动启动发电(Belt-driven Starter Generator BSG)系统中的BSG电机进行磁场设计研究。本文针对爪极混合励磁BSG电机初始设计方案中气隙磁通密度低、磁场调节范围窄、发电性能和低速输出性能较差等问题,对电机进行了优化设计。首先介绍该电机的结构特点和磁场调节原理。然后结合三维有限元仿真,对永磁体厚度、气隙大小、定子槽口宽度进行了优化,并对优化前后的电机进行了性能对比。优化后的结构具有磁通密度高,波形品质佳,发电性能好,启动转矩大等特点。最终制造样机并进行相关试验,样机试验与有限元分析结果吻合,验证了有限元仿真计算的准确性,进一步证明了分析的正确性。得到如下结论:1)在相同励磁电流下,永磁体厚度的设计存在最优值。如果永磁体厚度过小,则永磁体的增磁效果不明显;如果永磁体厚度过大,虽然能提高电机的气隙磁密,但漏磁系数也会增大,从而限制了电机气隙磁密的大幅提高,永磁体的材料利用率不高。2)随着气隙的减小,漏磁减小,反电动势的幅值及其电压波形畸变率增大。3)槽口宽度主要影响反电动势的电压波形畸变率而对其幅值影响较小。随着槽口宽度的增加,电压波形畸变率逐渐增大最终趋于稳定。更多还原

【Abstract】 As the world is facing both environmental problems and energy crisis,the State Council promulgated <Chinses Manufacture 2025> for the automotive industry,which puts forward strict requirements on the fuel consumption of automobiles.With the advantages of small modification,low cost,mass production,energy saving and emission reduction,micro-hybrid vehicle has a good application prospect and research value.In this paper,the magnetic field design of BSG motor in the Belt-driven Starter Generator(BSG)system is studied.Aiming at the problems of low air gap flux density,narrow magnetic field adjustment range,poor power generation performance and low speed output performance in the current claw-pole hybrid excitation BSG motor design,the motor is optimized.Firstly,the structural characteristics and magnetic field adjustment principle of the motor are introduced.After that,the thickness of the permanent magnet,the size of the air gap and the width of the stator slot are optimized by the three-dimensional finite element method.The performance of the motor before and after optimization were compared.The optimized structure has the characteristics of high flux density,good waveform quality,good power generation performance and large starting torque.Finally,the prototype test was designed and manufactured.The results of prototype test was consistent with the finite element analysis results.The accuracy of the finite element simulation is verified,and the correctness of the analysis is further proved.And the following conclusions are obtained:(1)Under the same excitation current,there is an optimal design value for the thickness of permanent magnet.If the thickness of permanent magnet is too small,the magnetization effect of permanent magnet is not obvious;If the thickness of the permanent magnet is too large,the material utilization rate of the permanent magnet is not high.Because with the increase of the thickness of permanent magnet,the leakage coefficient will increase,which limits the large increase of the air gap magnetic density of the motor.(2)With the decrease of air gap,the leakage flux decreases,which causes the increase of the amplitude of back EMF and the distortion rate of voltage waveform.(3)The width of the notch has little influence on the amplitude of the back electromotive force,which mainly affects its voltage waveform distortion rate.With the increase of the notch,the voltage waveform distortion rate is gradually increased and eventually stable.更多还原