Analytic expression of magnetic field distribution of rectangular permanent magnets
Analytic expression of magnetic field distribution of rectangular permanent magnets
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DOI：
10.1007/bf02437333
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发表时间：
2004-03
影响因子：
--
通讯作者：
Gou Xiao-fan;Yang Yong;Zheng Xiao-jing
中科院分区：
文献类型：
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作者：
Gou Xiao-fan;Yang Yong;Zheng Xiao-jing
从分子电流的观点出发，从毕奥-萨伐尔定律出发，导出了一个精确描述单向充磁的矩形永磁体的磁场分布的解析表达式。该表达式不仅适用于一个矩形永磁块的情况，而且适用于多个矩形永磁块的情况。利用该公式，详细讨论了矩形永磁体的大小、磁场大小和空间中点到矩形永磁体顶(底)面的距离与磁场分布的关系。计算结果与实验结果吻合较好。对于矩形永磁体的主磁场-横向磁场，为了描述其分布，定义了两个量，一个是磁场的大小均匀，另一个是磁场分布的均匀。并利用这些公式研究了它们与永磁体几何尺寸以及与永磁体表面的距离之间的关系。数值结果表明，几何尺寸和距离对磁场的大小和分布的均匀性有明显的影响。
From the molecular current viewpoint, an analytic expression exactly describing magnetic field distribution of rectangular permanent magnets magnetized sufficiently in one direction was derived from the Biot-Savart’s law. This expression is useful not only for the case of one rectangular permanent magnet bulk, but also for that of several rectangular permanent magnet bulks. By using this expression, the relations between magnetic field distribution and the size of rectangular permanent magnets as well as the magnitude of magnetic field and the distance from the point in the space to the top (or bottom) surface of rectangular permanent magnets were discussed in detail. All the calculating results are consistent with experimental ones. For transverse magnetic field which is a main magnetic field of rectangular permanent magnets, in order to describe its distribution, two quantities, one is the uniformity in magnitude and the other is the uniformity in distribution of magnetic field, were defined. Furthermore, the relations between them and the geometric size of the magnet as well as the distance from the surface of permanent magnets were investigated by these formulas. The numerical results show that the geometric size and the distance have a visible influence on the uniformity in magnitude and the uniformity in distribution of the magnetic field.