爪极发电机负载漏磁计算

Magnetic Leakage Computation of Claw-Pole Alternators under Load

采用三维瞬态有限元方法对一台电励磁爪极发电机和一台混合励磁爪极发电机进行了负载漏磁计算。爪极发电机的特殊爪极结构决定了电机磁场呈三维分布,需要用三维数值方法计算。首先对永磁体进行了优化分析,确定了永磁体牌号和三维尺寸。接着分析了两种电机的气隙磁密波形。然后得到了在输出恒压的前提下两种电机不同转速和不同励磁电流下的负载平均漏磁系数以及最大输出功率。并且得出了两种电机效率与负载平均漏磁系数的变化关系。最后,计算值与样机实测值的一致性验证了计算结果的有效性。

Using a three- dimensional（ 3D） transient finite element（ FE） method,the load magnetic leakage was computed for both an electric excitation claw- pole alternator and a hybrid excitation claw- pole alternator. The special shape of the claws leads to a truly 3D magnetic field in all regions. Consequently,for the correct calculation of magnetic field and alternator characteristics,a 3D numerical method is required. Based on the optimization of the permanent magnet（ PM）,the grade and dimensions of PM were obtained. The air gap flux density of two alternators was also analyzed. In addition,the average load magnetic flux leakage and the maximum output power were computed for two alternators in terms of different speed and excitation current. In addition,the relationship between the efficiency and the average load magnetic flux leakage for two alternators was presented. Finally,the consistency of calculated and measured values verified the validity of the calculation results.