Halbach阵列无轴承永磁电机有限元分析

Finite element analysis of bearingless permanent magnet motors with Halbach array

针对气隙磁密对无轴承永磁电机可靠性、转矩脉动及径向悬浮力的影响,提出了Halbach阵列永磁转子结构。从无轴承永磁电机的转子结构出发,对常规面贴式永磁转子和Halbach阵列永磁转子进行了比较分析,并用Ansoft进行了有限元分析,得出了两种不同转子结构的磁力线分布图及气隙磁密波形,分别对两种转子结构的无轴承永磁电机的径向悬浮力与悬浮力绕组电流的关系进行了对比。分析结果表明:Halbach阵列应用在无轴承永磁电机中能显著提高气隙磁密及其正弦特性,增大径向悬浮力。Halbach阵列应用于无轴承永磁电机具有可行性和可靠性。

Aiming at the influence of air gap magnetic density on the dependability, the torque ripple and the suspension force of bearingless permanent magnet motors, the structure of Halbach array permanent ro- tor is proposed. From the structure of permanent magnet rotors in bearingless permanent magnet motors, the conventional surface mounted and Ha｜bach array permanent magnet rotors were compared and ana- lyzed. Then a finite element analysis with the software of Ansofi was presented, and magnetic field lines and air gap magnetic density of the two different rotor structures were calculated. Finally, the relations between suspension forces and currents in the suspension windings in bearingless permanent magnet mo- tors with the different rotor structures were compared. The result shows that the air gap magnetic density with fine sinusoidal waveform is enhanced, and suspension force is improved by using Halbach array in bearingless permanent magnet motors. Halbach array has reliability and feasibility when used in bearing- less permanent magnet motors.