油冷气隙绕组端部强化换热的数值研究

高速或强励磁旋转油冷电机在工作时,气隙绕组温度分布不均匀,绕组端部的温度明显高于绕组直线段温度,极大地影响油冷电机效率。本文采用数值模拟的方法研究了不同形状,间距的翅片结构对油冷电机气隙绕组端部的最高温度,热工水力性能的影响,发现在气隙绕组端部安装形状为梯形,间距为10 h的翅片具有较好的强化换热效果,为高速或强励磁油冷电机气隙绕组的冷却设计提供了有效的技术支撑。

被动补偿脉冲发电机气隙绕组电感的解析计算

利用电磁计算的直观图解法 ,考虑到导电筒中涡流产生的磁通压缩效应 ,通过分析气隙磁场分布导出了被动补偿脉冲发电机无槽电枢绕组电感的解析表达式。对 2 5MW样机进行了计算。电感的测量结果验证了解析表达式的有效性。

无轴承异步电动机的系统实现

在对无轴承交流电机的磁悬浮机理进行一般性描述的基础上,采用电枢绕组气隙磁场定向控制来实现转矩控制和悬浮力控制之间的动态解耦,并以无轴承鼠笼式异步电动机为研究对象,研制了一套控制系统,并在原理样机上进行实验,实现了转子轴的稳定悬浮,而且动态性能良好,验证了提出的无轴承异步电动机控制系统的可行性.

A Simple Approach to Air-Gap Armature Reaction Field Computation in Fractional-Slot SPM Multiphase Machines

Fractional-slot concentrated-coil electric machines are often used in those applications where a number of rotor poles close to the number of stator slots is required. A major criticality of such machines is the occurrence of large air-gap field harmonics due to winding distribution and to slotting effects. Predicting such harmonics analytically with adequate accuracy is a good way to significantly speed-up subsequent investigations, concerning the rotor effects of the field harmonics in terms of rotor losses. This paper proposes different analytical formulations for this purpose, covering the case of a generic number of stator phases and differing by how slotting effects are taken into account. The various approaches proposed are evaluated by comparing analytical results with finite-element analysis computations on a sample machine geometries.