永磁同步发电机齿槽转矩削弱方法研究

Research on weakening method for cogging torque in permanent magnet synchronous generator

永磁同步发电机在风力发电系统中应用越来越广泛,然而由永磁体与有槽定子铁芯之间的相互作用产生的齿槽转矩,会引起振动和噪声,并影响风力发电系统的控制精度。文章推导了基于能量法和傅里叶分解的齿槽转矩表达式,分析了削弱齿槽转矩的影响因素,提出了一种基于开辅助齿的削弱齿槽转矩的方法。在此基础上,给出了开辅助齿情况下的傅里叶分解系数,并分析了辅助齿宽度以及辅助齿高度对齿槽转矩的影响。最后利用有限元法对其进行了验证,结果表明,采用1/3槽宽的辅助齿宽度时,齿槽转矩基波分量减小了39.08%,有限元方法计算结果证明得出的结论是正确有效的,所得结论可为进一步优化永磁电机设计提供理论依据。

The application of permanent magnet synchronous generator （PMSG） in wind power generation system becomes more extensive. However, the cogging torque caused by the interaction between the permanent magnet and slotted stator core can lead to the vibration and the noise, and affect the precision control of wind power generation system. Using energy method with Fourier series expansion, a weakening method for cogging torque by opening auxiliary tooth is proposed in this paper, and the influencing factors which could weaken cogging torque are ana- lyzed. On the basis above, the Fourier decomposition coefficients are deduced. In addition, the influence of the auxiliary tooth on cogging torque is analyzed in detail. Finally, the validity of the proposed method is verified by fi- nite element method. The results show that when the auxiliary tooth width of third groove width is adopted, the fun- damental component of cogging torque is reduced by 39.08% , and the calculation result by finite element method proves that the conclusion is correct. The conclusion can provide a theoretical basis for further optimization of per- manent magnet motor.