Take a 150MW air cooled turbo-generator as an example. In order to investigate the influence of strand structure on saturation parameters and stator temperature, the solving region and mathematical model were given. Using finite element method, the loaded field was calculated for two structures of stator windings with inequality strands and sections and equality strands and sections of upper and bottom windings under rated load using numerical methods. And variation of flux through teeth and slots of stator along stator inner circle circumferentially was analyzed. The variation of magnetic field under different structures of stator winding was got. Based on the above-calculated loaded field, direct and quadrature axis synchronous reactance were calculated under rated load with two structures of stator windings. The influences of magnetic vector potential of different positions of stator windings on saturated reactance Xd and Xq were analyzed. Besides, the influences of parameters Xd and Xq under overload on stator temperature distribution were analyzed with two structures. Within the same wind structure, the temperature distribution of the stator under overload is consistent. Under different overloads, the tempearture of teeth and yokes changes little and the position of the highest temperature also does not change.%以150MW空冷汽轮发电机为例,为研究定子绕组异结构对发电机饱和参数与温度场的影响,给出发电机的求解域和数学模型.利用有限元方法,计算了汽轮发电机在额定状态下,定子绕组上、下层线棒不等股数不等截面和等股数等截面两种结构下的负载场,并分析了穿越气隙进入定子齿槽的磁通大小及沿定子内圆周向的变化情况,得到定子绕组不同结构下,磁场的变化情况;在负载场基础上,计算了额定状态下的定子绕组两种结构时的直、交轴同步电抗,并分析了定子绕组不同位置的矢量磁位对饱和电抗值Xd和Xq大小的影响.基于上述电磁场计算结果,分析了两种结构过载情况时电机参数Xd和Xq与定子温度分布的变化情况.研究发现两种结构的直、交轴同步电抗的标幺值相差不大,同一种结构不同过载状态下温度变化趋势基本一致,且齿部和轭部温度变化不大,最高温度出现的位置也没有变化.
展开▼
