摘要
高效率、高转矩密度特性使得永磁电机的应用越来越广泛,然而永磁电机的齿槽转矩却降低了电机的性能。根据对槽漏磁导(是否考虑槽漏磁)、空载气隙磁密(是否考虑永磁体之间的漏磁、是否考虑圆周曲率)的不同处理和采用不同的计算方法(能量法、齿壁受力),给出了齿槽转矩的六种解析模型,并进行了比较。根据模型,得到了三种槽数/极数(18/24、9/8、24/16)电机的齿槽转矩的波形、使齿槽转矩最小化的优化极弧系数和优化槽开口,并与有限元(FEA)进行了比较。结果表明计及槽漏磁和永磁体间的漏磁大大提高了模型的精确度,而根据齿壁受力计算得到的齿槽转矩比能量法得到的齿槽转矩更加精确。
Permanent magnet brushless machines exhibit high efficiency and torque density, and have already been widely employed. However, one of their disadvantages is the inherent cogging torque, which is a kind of torque ripple and always desirable to minimize. Six analytical models for cogging torque prediction are presented and compared in this paper. These analytical models are progressively refined and differ in methods for calculating the permeance due to stator slotting （i. e. with/without considering the slot leakage）, the airgap field distribution due to permanent magnets （i. e. with/without considering the inter-pole leakage and/or curvature effect）, and the cogging torque （based on the energy method or the net lateral force acting on the stator teeth）. Developed analytical models are used to predict the cogging torque waveforms, the optimal magnet pole-arc to pole-pitch ratio and the optimal slot opening in three machines having different combinations of slot number and pole number, viz. 18/24, 9/8, and 24/16, respectively, and are extensively validated by the finite element analyses. It shows that accounting for the slot leakage and/or magnet interpole leakage can significantly improve the accuracy of cogging torque prediction, while the method for predicting the cogging torque based on the calculation of net lateral force acting on the stator teeth exhibits a higher accuracy than that based on the energy method.
出处
《微电机》
北大核心
2010年第1期10-15,共6页
Micromotors
关键词
模型
齿槽转矩
永磁电机
转矩波动
Analytical model
Cogging torque
Permanent magnet machines
Torque ripple
