转子偏心对U型单相永磁同步电机的影响

Rotor Eccentricity Affecting the Performance of U-shaped Single-phase Permanent Magnet Synchronous Motor

为了研究转子偏心对U型单相永磁同步电机性能的影响,采用有限元法分析了电机内的电磁场,在虚位移法和麦克斯韦应力法的基础上,计算了当转子分别发生静态偏心和动态偏心时,电磁转矩的变化量以及定子侧所受到的径、切向电磁力。并通过傅里叶分解,研究了转子偏心对电磁力波阶次和频次的影响。计算结果表明,转子偏心引起电机内电磁场不对称分布,且气隙磁密幅值随偏心距离的增加而增大;不同偏心状态对电磁转矩波动有不同的影响;偏心导致电磁力波奇次谐波分量大幅度增加。

In order to analyze the impact of rotor eccentricity to the performance of u-shaped single-phase permanent magnet synchronous motor,the finite element method is adopted to analyze the electromagnetic field inside the motor.On the basis of the virtual work method and the Maxwell stress tensor method,the variation of electromagnetic torque,radial and tangential electromagnetic force densities in stator side were calculated when static eccentric and dynamic eccentric occurred in rotor.Then the influences of rotor eccentricity on the electromagnetic force order and frequency were studied through the Fourier decompose.The calculation results indicate that asymmetrical distribution of electromagnetic field in the electric machine due to rotor eccentricity,and the air gap flux density amplitude increases with the increases of the eccentric distance;different eccentric states have different effects on the electromagnetic torque volatility;eccentric results in a substantial increase of electromagnetic force odd harmonic component.