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

我们开发了一种技术来预测在具有复杂磁化模式的电气和电子设备中使用的磁体的磁通量损失。所开发的方法使用有限元法，包括四个步骤。首先，分析磁化场下的磁化分布（步骤1），并从第一步的结果推导出每个元件的退磁曲线（步骤2）。随后，通过使用在步骤2中确定的退磁曲线来分析室温和高温下的磁化分布（步骤3）。在步骤4中，通过使用步骤3中的结果，基于物理模型预测由于暴露在高温下而导致的通量损失的分布。我们将此技术应用于10极环形Nd-Fe-B磁体，并证实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.