离散式任意充磁角度Halbach永磁电机解析模型研究

Analytic model of discrete random magnetizing Halbach PM motor

Halbach电机因其自身优势在新型船舶推进、海洋洋流发电等方面受到广泛关注.本文在假设铁磁材料线性和定子内表面光滑的条件下,通过将任意充磁角度Halbach阵列等效为两组90°Halbach(或180°Halbach)阵列的矢量合成,提出了一种分析离散式任意充磁角度Halbach永磁电机气隙磁场的解析方法;通过对电机中磁标量势的傅里叶级数进行计算,推导出了最简单的90°Halbach永磁电机在极坐标系下的气隙磁密表达式,并在此基础上,给出了任意充磁角度Halbach电机永磁体磁化强度在一个极下的表达式,进而得出任意充磁角度Halbach电机气隙磁密的分布,并分析了气隙磁密与电机极对数、永磁体厚度和充磁角度间的关系.最后通过有限元和试验结果验证了本文方法的正确性.

Halbach motors have attracted lots of attention in novel ship propelling and ocean current generators as they have much dominance. Under the condition of ideal ferromagnetic material and slotless stators, randomly magnetized Halbach array is considered as an equivalence of two 90°Halbach （180°Halbach） arrays, and a new analytic method is proposed in this paper to analyze the randomly magnetized Halbach motors. Fourier series of magnetic scalar potential is calculated, and the expression of air-gap flux density of a 90°Halbach motor is given in polar coordinate system. On the basis of calculations above, the magnetization intensity expression of a randomly magnetized Halbach motor in a pole, and the air-gap flux density distribution of randomly magnetized Halbach motor are obtained; and the relationship of air-gap flux density between the numbers of poles, permanent magnet thickness as well as magnetizing angle are analyzed. The finite element method and experimental results verify the effectiveness of the methods above.