发电机定子绕组端部电磁力特性与鼻端扭矩计算

Computation and Characteristic Analysis on Electromagnetic Force and Nose Torque of Stator End Windings in Turbo-Generator

针对大型汽轮发电机端部结构,提出了采用镜像原理、比奥萨格尔定律和叠加原理计算定子绕组端部电磁力密度解析式的方法。以国产600MW汽轮发电机定子绕组端部为分析对象,分别对一个极距内定子端部绕组在出槽口直线段、渐开线段和鼻端等不同位置处的轴向、径向、切向和合成的电磁力密度进行计算与分析。结果表明,各相绕组内线棒所受的轴向、径向、切向电磁力密度和合成的最大值出现的位置是有规律的,一般位于相带交界处,相带始端或相带末端,并给出了在出槽口部分、渐开线部分和鼻端部分所受力最大值及其位置。计算了鼻端所受的扭矩,并找出了最大扭矩出现的位置,为定子绕组端部的绑扎固定和在线监测提供了参考。

A method of computing the electromagnetic force expression of end windings based on image theory,the Biot-Savart Law,and the superposition principle is proposed for the end structure frame of a large-capacity turbo-generator.On the basis of a 600 MW homemade large-capacity turbo-generator,the axial,radial,tangential and resultant electromagnetic force density of the stator end windings′exiting slot part,involute part,and nose part in a pole pitch are computed and analyzed,respectively.The results show that the location of the maximal axial,radial,tangential and resultant electromagnetic force densities acted on the bars in different windings regularly located in the juncture,beginning or ending of the windings.The maximal electromagnetic force density and its location in the exiting slot part,involute part and nose part are obtained.Finally,the torque acting on the nose for the first time is computed,and the location of the maximal torque can be obtained.The results provide some instructive references for the fixture of the binding and online monitoring of the stator end windings.