The magnetization of rare earth ring magnets forming the rotor of a BLDC or a synchronous motor requires a high level of magnetization field to achieve the desired magnetization pattern. The design of the magnetizing yoke is a compromise between the field strength requirements, the yoke temperature balance and the winding forces. The two-pulse magnetization allows reaching a higher steepness of magnetization at the pole edges and thus higher overall rotor magnetization under these difficult conditions. The magnetization fixture for the double-pulse method was designed and verified by finite element method simulations. A small series (100 pcs) of produced magnets are compared with simulations using external magnetic 3D field scanning. The artifacts (asymmetry of pole magnetization) after the two-pulse magnetization are recalculated onto unbalanced magnetic pull and torque ripple. It is shown that these artifacts do not adversely affect unbalanced magnetic pull and torque ripple, unlike the asymmetries caused by the geometric inaccuracy of the magnetizer, whose impact is crucial.

中文翻译：

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无刷直流电机用钕铁硼多极环形磁铁的两脉冲磁化过程

构成 BLDC 或同步电机转子的稀土环形磁铁的磁化需要高水平的磁化场才能实现所需的磁化模式。磁轭的设计是场强要求、轭温度平衡和绕组力之间的折衷。双脉冲磁化允许在磁极边缘达到更高的磁化陡度，从而在这些困难条件下实现更高的整体转子磁化。双脉冲方法的磁化夹具是通过有限元方法模拟设计和验证的。将一小批（100 个）生产的磁铁与使用外部磁场 3D 场扫描的模拟进行比较。两脉冲磁化后的伪影（磁极磁化的不对称性）被重新计算为不平衡的磁拉力和转矩脉动。结果表明，这些伪影不会对不平衡的磁拉力和转矩脉动产生不利影响，这与磁化器几何不准确引起的不对称不同，其影响至关重要。