【作者】 张震；

【导师】 姜文颖；

【作者基本信息】 南京航空航天大学 ， 电气工程， 2019， 硕士

【摘要】 永磁同步电机(permanent magnet synchronous motor,PMSM)由于具有高功率密度、高效率等优点,在电动汽车牵引电机中得到了广泛的应用。在电机实际运行中,由于控制系统中逆变器的影响,绕组电流会出现电流谐波,另外由于加工装配误差导致的转子偏心,均引起损耗增大和加剧振动噪声等问题。现在的电机设计中,大多是基于理想电流激励对电机性能进行评估,为提高准确性,需要建立电机及其驱动系统模型,针对实际工作条件下的电机电磁特性进行分析。本文以一台48槽/8极内置式永磁同步电机为例,建立了电机及其驱动系统模型,通过分析电机在各种激励(正弦电流源、正弦电压源和逆变器提供的斩波电压)条件下的电磁特性,对比分析实际控制系统对电机性能的影响。在此基础上,基于有限元仿真得出的电机参数建立查表模型,以加快仿真速度,并在实验中验证了其有效性。另外针对在实际电机中普遍存在的转子偏心问题,分析驱动系统中电机转矩、损耗等电磁特性受转子偏心的影响,并分析在偏心情况下的气隙磁密和电磁力密度谐波成分。并在不同控制模型中对发生转子偏心的电机进行分析,观察转子偏心问题带来的各相之不平衡问题。另外分析采用不同的绕组结构时电机在转子偏心状态下的电磁特性,从而找出较优的绕组结构以抑制转子偏心的影响。针对交流铜损较为显著的发卡式绕组永磁同步电机,利用电机及其驱动系统模型,分析实际系统中的电流谐波对电机铜损的影响。从控制系统参数和电机本体结构方面分析影响铜损的因素,并给出了抑制环流和减小铜损的绕组结构。更多还原

【Abstract】 The permanent magnet synchronous motors(PMSM)have been widely used as traction machines in electrical motors.In actual working condition,the current harmonics in windings brought by the inverter in the control system and the rotor eccentricity caused by manufacturing and assembly errors will increase the power loss,noise,vibration and harshness(NVH).The common method used for analyzing of the electromagnetic characteristics of PMSM is based on ideal sinusoidal current excitation.To improve the accuracy of the analysis,the actual control system needs to be considered.In this article,a 48-slot/8 poles interior PMSM considered the control system is analyzed,and the influence of the control system is compared by different excitations(sinusoidal current source,sinusoidal voltage source and voltage from inverter).Moreover,a look-up table motor model is adopted to reduce the computing time.Experiments are conducted to verify the effectiveness of these models.The influence of rotor eccentricity which commonly exists in actual motors are analyzed based on the control systems,especially on the torque,loss,flux density and electromagnetic force.The imbalance of three phases are observed by analyzing the motor with rotor eccentricity in different systems.Besides,the behaviors of model with different winding configurations in eccentricity state are compared to reduce the influence of rotor eccentricity.Study has been conducted on AC copper loss of hairpin windings PMSMs which is large especially at high speed based on the control systems,considering the influence of current harmonics.The influence factor for AC copper loss has been analyzed in the control system and the motor structure.Suitable winding configurations are pointed out to avoid the circulating currents and reduce the AC copper loss.更多还原