Development of Prediction Method of Thermal Flux Loss in Permanent Magnet Used in Electrical and Electronic Devices

我们开发了一种预测具有复杂磁化模式的电气和电子设备中磁体的磁通损失的技术。该方法采用有限元法，分为四个步骤。首先分析磁化场作用下的磁化强度分布（步骤1），并根据第一步（步骤2）的结果推导出各元件的退磁曲线。随后，使用步骤2（步骤3）中确定的退磁曲线分析室温和高温下的磁化分布。在步骤4中，利用步骤3中的结果，基于物理模型预测高温下暴露引起的通量损失分布。将该方法应用于10极Nd-Fe-B环形磁体，并证实了预测的磁通损失值与实验结果一致。

We developed a technique to predict flux loss of a magnet used in electrical and electronic devices with a complicated magnetization pattern. The developed method uses the finite element method and consists of four steps. At first, the distribution of magnetization under magnetizing field is analyzed (Step 1), and a demagnetization curve of each element is deduced from the results of the first step (Step 2). Subsequently, the distributions of magnetization at room and elevated temperatures are analyzed by using demagnetization curves determined in Step 2 (Step 3). In Step 4, the distribution of flux loss due to exposure at the elevated temperature is predicted based on a physical model by using the results in Step 3. We applied this technique to a Nd-Fe-B ring shaped magnet with 10 poles, and confirmed that the predicted flux loss values agreed with those obtained experimentally.