大型水轮发电机阻尼条数对电磁参数和附加损耗的影响

Influence of damper winding on electromagnetic parameters and additional loss of large hydo-generator

针对大型水轮发电机稳态运行时阻尼条根数的变化对附加损耗的影响,以五强溪电站水轮发电机为例,结合发电机结构的对称性,给出相应的求解域和数学模型,利用有限元方法,计算水轮发电机在稳态运行时,极靴表面阻尼条分别为6根和8根2种结构下的电磁场。在此基础上,计算稳态运行时极靴表面2种结构的直、交轴同步电抗和直轴瞬态电抗,稳态运行时,阻尼条增加2根后对直轴和交轴同步电抗和直轴瞬态电抗影响均不明显。将计算结果与实验值进行比较,计算结果满足工程实际要求。此外,计算2种结构下空载和负载时的附加损耗,结果表明阻尼条根数增加,空载额定电压时极靴表面的附加损耗略增加,定子绕组高次谐波在极靴表面产生的附加损耗略小。

Considering the effect of damping bars on additional losses,the hydraulic generator in Wuqiangxi power station was taken as an example.For the symmetrical structure of hydraulic generator,the solved region and mathematical model were given.Using the finite element method,the electromagnetic field of hydraulic generator with 6 and 8 damping bars were calculated separately while the large hydro-generator was in steady-state operation condition.The direct-axis synchronous reactance,quadrature axis synchronous reactance and transient reactance of two different hydraulic generator structures were calculated.With increasing two damping bars,direct-axis synchronous reactance,quadrature axis synchronous reactance and transient reactance did not change significantly.Compared with the experimental values,the calculated results are in actual engineering requirements range.Besides that,the additional losses of the generator no-load and in load situation were calculated,and the additional losses increased with increasing the number of damping bar.The additional losses on boots surface of generator with 8 damping bars produced by stator winding higher harmonics are slightly smaller than the generator with 6 damping bars.