转子偏心对发电机非正规绕组环流损耗的影响

摘要

In order to research the influence of static eccentricity on circulating current and circulating current losses of asymmetric-branch winding in turbo-generator,a 397 MW turbo-generator with two poles was taken as an example and its two-dimensional transient finite element model was established for calculating circulating current of each branch in stator winding by different rotor eccentricities.Variations and harmonic contents of circulating current in each branch were obtained,and based on that,the corresponding circulating current losses were calculated.Finally,the results are compared with that of symmetric-branch winding.Analysis shows that the circulating current losses of asymmetric-branch winding increases with the growth of eccentricity in the case of static eccentric.Under the same eccentricity,the circulating current losses of asymmetric-branch winding are greater than symmetric-branch winding.Influence of the circulating current losses should be fully considered in the engineering design of asymmetricbranch winding.%为研究转子静态偏心对汽轮发电机支路不对称绕组环流及环流损耗的影响,以一台2极397 MW汽轮发电机为例,建立了其二维瞬态场有限元求解模型,对电机转子在不同偏心率下的定子绕组各支路环流进行了分析计算,得到了支路环流随时间的变化规律,给出了各支路环流的谐波含量,并在此基础上求取了支路环流损耗;最后将计算结果与支路对称时的情况进行了对比.分析结果表明,转子静态偏心情况下支路不对称绕组的环流损耗随着偏心率的增大而增加,在相同的偏心率下支路不对称绕组的环流损耗大于支路对称绕组的环流损耗,在支路不对称绕组的工程设计中应充分考虑环流损耗所带来的影响.