航空高速起发电机转子永磁体预应力设计

Permanent Magnet Prestress Control of Aero High-speed Starter Generator Rotor

航空高速起发电机在可靠性方面要求高,对于带护套的表贴式高速永磁起发电机,永磁体预应力是通过在永磁体表面过盈压装非导磁合金护套实现,因此转子结构设计时需要合理的预应力设计。本文建立一种温度补偿的航空高速起发电机转子永磁体预应力设计仿真模型。以一台最高转速55000 r/min的无人机用表贴式起发电机为例,分析过盈量对永磁体静态预应力的影响,在此基础上,计算并总结转子各部分动态应力随电机转速、温度、永磁体分段等因素的变化规律,为同类型电机设计提供参考。最后对一台起动功率20 kW、额定发电功率4 kW、最高转速55000 r/min的高速起发电机进行实验验证,证明计算结果的有效性。

Aero high-speed generators have high reliability requirements.For surface-mounted high-speed permanent magnet generators with sheaths,the permanent magnet prestress is achieved by press-fitting a non-magnetic conductive alloy sheath on the surface of the permanent magnets.Therefore,reasonable prestress control is required in rotor structure design.In this paper,a simulation model of prestress control for the rotor of aero high-speed generator with temperature compensation was established.A surface-mounted generator with a maximum speed of 55000 r/min was taken as an example to analyze the influence of the interference on the static prestress of the permanent magnet.On this basis,the variation law of dynamic stress of each part of the rotor with the motor speed,temperature,permanent magnet segmentation and other factors was calculated and summarized,which provided a reference for the design of the same type of motor.Finally,a high-speed starter generator with a starting power of 20 kW,a rated generating power of 4kW and a maximum speed of 55000 r/min was experimentally verified to prove the validity of the calculation results.