兆瓦级高速永磁电机通风系统设计与转子表面风摩耗研究

Ventilation system design and research on wind friction loss of rotor surface of MW high-speed permanent magnet motor

针对兆瓦级高速永磁电机的损耗密度大、散热困难、永磁体在高温情况下易发生不可逆退磁的问题,提出了一种径向与轴向混合的⊥型通风系统,通过流体仿真软件Fluent建立了该种通风系统的3D流体场计算模型,并详细分析了通风系统内的流体分布;同时针对高速电机转子表面线速度高(一般可达200 m/s)、转子表面的风摩耗较大且计算复杂的问题,基于所建立的3D流体场模型和解析法,对兆瓦级高速永磁电机的转子转速、转子表面粗糙度及通风量、风道几何参数、气隙大小对转子表面风摩耗的影响进行了研究计算,并总结了相应的规律。分析结果表明,所设计的混合⊥型通风系统具有较好的湍流特性和散热特性,转子转速和气隙大小是影响风摩耗的主要因素。

Due to high loss density, cooling difficulties, permanent magnet being easy to occur irreversi-ble demagnetization at high temperatures of MW high-speed permanent magnet motor, a kind of radial and axial mixed⊥-shaped ventilation system is presented. Fluid field analysis model of the rotor cooling system was established through fluid simulation software computational fluid dynamics（CFD）-fluent, and then the detailed analysis of fluid distribution was carried out within the ventilation system. At the same time, according to high line speed of rotor surface （generally up to 200 m/s）, large wind friction loss of rotor surface and complex calculations, the relationship between wind friction loss and rotor speed, the roughness of rotor surface, ventilation quantity, duct geometric parameters and air gap sizes were investi-gated and generalized based on the established 3D fluid field analysis model and analysis method. The re-sults of analysis show that the mixed ⊥-shaped ventilation system has good characteristics of turbulence and heat dissipation, and the main factors affecting wind friction loss are rotor speed and gap sizes.