磁钢充磁方式对稀土永磁斜槽电机性能的影响分析  

Influence of Different Magnetization Manners on Rare Earth Permanent Magnet Electrical Machines with Slot Skew

作　　者：刘景林[1] 王立[1] 

机构地区：[1]西北工业大学稀土永磁电机及控制技术研究所,陕西西安710129

出　　处：《稀土》2014年第1期16-23,共8页Chinese Rare Earths

基　　金：陕西省自然科学基金资助项目(2011GZ013)

摘　　要：月球车驱动电机要求效率高、体积小、功率密度大、转矩脉动小,方波电流驱动的定子斜槽、内转子表贴式稀土永磁无刷直流电机是理想选择。为快速且准确地计算月表极限温度下、磁钢采用不同充磁方式的斜槽电机的性能,基于分段模型中直槽单元串联等效斜槽的思想,利用改进的2D有限元方法建立了斜槽电机的等效模型,提出一种高效求解电机性能的方法,采用最小几何研究域耦合恒流源型外部控制电路,使分段直槽电机单元的同槽绕组电流相等。该方法实现简单、计算量小,样机实测结果证明了该方法的有效性。研究表明,不同磁钢充磁方式下,采用斜槽均能有效抑制电机的空载感应电势的高次谐波分量和齿槽转矩;与径向充磁相比,磁钢采用平行充磁方式的斜槽电机的空载感应电势的幅值和气隙磁通更大。The drive motors of lunar rover should possess high efficiency,small volume,high power density and low torque ripple. The surface- mounted rare earth permanent magnet brushless DC motor with skewed stator slot and inner rotor driven by trapezoidal current is one of the ideal choices. The 3D finite element model was adopted to analyze the electrical machines with slot skew commonly,and the computing process was extremely time- consuming due to the huge calculation amount. In order to compare the performance of radial magnetization skewed motor with that of parallel magnetization skewed motor at extreme temperatures of lunar surface,a multi- slice model was adopted and a skewed slot was equivalent to a certain number of straight slot units in series. The equivalent model of skewed motor based on improved 2D finite element method was built and an efficient method of performance computation was proposed. The external control circuit with ideal current source was coupled with the minimum geometry research domain to equalize the winding currents in the same slot of straight slot motor units. The realization of the proposed method was simple and timesaving,and the effectiveness was proven by the prototype test. The research shows that the high harmonics of no- load back- EMF and cogging torques are weakened significantly in virtue of the adoption of slot skew,and the amplitudes of no- load back- EMF and air- gap normal flux of parallel magnetization skewed motor are larger than those of radial magnetization skewed motor.

关 键 词：磁钢充磁方式 稀土永磁 斜槽电机 分段模型 

分 类 号：TM301.4[电气工程—电机]