CT直驱电机电磁设计及有限元分析

Electromagnetic Design of CT Direct Drive Motor and Finite Element Analysis

先进的医疗CT采用永磁电机直驱结构,提高了系统的响应速度和传动效率,但也对电机本体的振动噪声水平和大型定子加工装配技术提出更高的要求。本文首先根据医疗CT的使用工况计算了直驱电机的设计指标,从降低转矩脉动、电磁力波的角度,选择了合理的极槽配合,完成电机的基本电磁设计。此外,考虑大型定子的装配问题,在整圈定子基础上设计了分段定子方案,最后,通过有限元分析证明了设计的合理性,并从转矩脉动、损耗等方面对整圈定子和分段定子进行比较。

The advanced medical CT adopts the direct drive structure of permanent magnet motor to improve the response speed and transmission efficiency of the system, but also puts forward higher requirements for the vibration level and large stator processing and assembly technology. Firstly, according to the working condition of medical CT, the design index of direct drive motor was calculated to reduce torque ripple and electromagnetic force wave, the reasonable pole slot matching was selected to complete the basic electromagnetic design of motor. Besides, considering the assembly problem of large stator, the scheme of segmented stator was designed on the basis of the whole stator. Finally, the rationality of the design was proved by the finite element analysis, with the whole stator and segmented stator compared from torque ripple and loss.