双斜槽感应电机气隙偏心时的径向电磁力分析

Analysis of radical electromagnetic forces of induction motor with double skewed slots under air-gap eccentricity

为了分析双斜槽感应电机偏心情况下的电磁激振力,以一台笼型双斜槽感应电机为例,采用解析法分析了动偏心和静偏情况下的气隙磁密成分,并得到了不同阶次谐波相互作用产生的平均径向电磁激振力的阶次与幅值表达式。针对双斜槽感应电机,提出了适用于双斜槽的多层分段有限元模型,并获得了径向气隙磁密与径向电磁激振力的时空分布。利用二维傅里叶分解法,获取了平均径向电磁力的时空频谱,并与直槽偏心时的径向电磁力相对比,发现双斜槽能够有效削弱由偏心导致的部分附加径向电磁力。

To analyze the electromagnetic force of a double skewed slot induction motor under air-gap ec-centricity ,a squirrel-cage induction motor with double skewed slot is taken as an example. The composi-tion of air gap magnetic flux density under dynamic eccentricity and static eccentricity was analyzed by analytic method. The expressions of the order and amplitude of the average radial electromagnetic exciting force generated by different order harmonic interactions were obtained. A multi-slice model suitable for double skewed slots was proposed in this paper. The time and space distributions of the radial flux density and the radial electromagnetic force were obtained. The two-dimensional Fourier decomposition method was adopted to get the space and time spectrum of the radial electromagnetic force. Compared with the straight slot, it is found that part of additional radial electromagnetic force caused by eccentricity is effec-tively weakened by double skewed slot.