稀土永磁斜槽电机分段建模及不同工作温度下的电磁性能计算

Multi⁃slice Model of Rare Earth Permanent Magnet Skewed Motor and Calculation of Electromagnetic Performance at Different Operating Temperatures

高可靠性是电机重要的指标之一。为确保电机驱动系统长期可靠运行,电机的电气性能应该保持基本不变。由于稀土永磁材料的固有特性,磁钢随工作环境变化会发生可逆或不可逆退磁。针对表贴式稀土永磁斜槽电机,基于分段思路,采用2D FEM建立了简化计算模型,计算了不同工作温度下磁钢于退磁曲线拐点以上发生可逆退磁后的电机性能,分析了磁钢及附近气隙区域的磁场,对比了感应电势和电磁转矩。研究结果表明,采用温度系数较小的稀土磁钢,即使工作温度在较大范围内变化,电机的电磁性能变化较小。实测结果证实了建模方法的有效性。研究结果为稀土永磁斜槽电机的电磁性能计算提供参考。

High reliability is one of the important indexes of motors.In order to ensure the long⁃term reliable operation of the motor drive system,the electrical performance of the motor should remain basically unchanged.Due to the inherent charac⁃teristics of rare earth permanent magnet materials,with the change of operating temperature,magnetic steel will be reversibly or irreversibly demagnetized.Aiming at the surface⁃mounted rare earth permanent magnet motor with skewed stator slot,a fast calculation model of electromagnetic performance is established based on the two⁃dimensional finite element method with multi⁃slice idea.The motor with reversible demagnetization of magnetic steel above the inflection point of demagnetization curve is calculated.The magnetic field of magnetic steel and its adjacent air gap area is analyzed.The EMF and electromagnetic torque are compared.The results show that the electromagnetic performance of the motor remains stable when the sintered Co⁃based rare earth magnetic steel with small temperature coefficient is adopted and the operating temperatures are-180℃,20℃and 150℃,respectively.The measured results of the prototype verify the effectiveness of the modeling method.The research re⁃sults provide a reference for the performance calculation of rare earth permanent magnet skewed motor.