全封闭高速永磁电机转子结构对转子散热的影响

为研究转子物理结构对机壳水冷全封闭式高速永磁电机转子散热的影响,以一台15k W、30 000r/min的非晶合金高速永磁电机为例,基于流体力学和传热学理论,建立三维流固耦合共轭传热求解域模型,并给出基本假设与边界条件,采用有限体积法进行流固耦合求解,得到转子有无轴向通风孔和通风孔与风刺相配合时电机内流体流动特性及各部件的温度分布。在此基础上,研究通风孔尺寸、通风孔数量变化对流体场及温度场的影响。计算结果表明,转子引入风刺和通风孔等风压元件可有效提高转子的散热能力,降低永磁体温升。通过增大通风孔尺寸和数量可进一步降低永磁体温升。最后,对一台15k W全封闭式水冷非晶合金永磁电机进行了温升试验,并将试验数据与计算结果进行对比,验证了耦合场计算结果的正确性。

Effect of Rotor Structure on Rotor Dissipation for Totally-Enclosed High-Speed Permanent Magnet Motor

In order to study the influence of rotor structure on rotor heat dissipation for totally enclosed water-cooling high speed permanent magnet motors (HSPMMs), a 15kW, 30 000r/min high-speed amorphous alloy permanent magnet motor was taken as an example. On the basis of computational fluid dynamics (CFD) and heat transfer theory, the computation model of fluid-solid conjugate heat transfer was established, and the coupled field was calculated using finite volume method by giving fundamental assumptions and corresponding boundary conditions. The temperature distributions of each part and air flow characteristics in the motor were obtained under several conditions, that is, with and without axial ventilation holes, the combination between ventilation holes and wafters of rotor. Thereafter, the influence of different ventilation hole sizes and number on fluid and temperature field were studied. The calculated results show that the cooling condition is improved, and the temperatures of permanent magnets are reduced by introducing the rotor wind pressure parts. The temperature of permanent magnet can further decrease by increasing the area of rotor ventilation holes. At last, the temperature rise test for a 15kW totally enclosed water-cooling HSPMSM was conducted. The test data were compared with the calculated results, which validated correctness of the solution method of coupled field.