1000MW水轮发电机不对称运行时阻尼条涡流损耗计算分析

摘要

针对大型水轮发电机不对称运行时阻尼条易熔断的现象，在建立电机二维电磁场一电路—运动耦合时步有限元模型的基础上，对一台1000MW水轮发电机不对称运行时阻尼条涡流损耗进行深入研究．全面考虑了定子开槽、磁极转动以及定子电流等因素对阻尼条涡流损耗的影响，准确计算出不同运行工况下一个磁极内各根阻尼条涡流损耗，分析其变化规律，并在此基础上讨论了阻尼系统连接方式、阻尼条半径、阻尼条材料对阻尼条涡流损耗的影响．研究结果表明，不对称运行时，沿旋转方向最后一根阻尼条涡流损耗最大，阻尼系统结构参数对阻尼条中涡流损耗分布有较大影响。%Aiming at the phenomenon that the damping bars would easily fuse under the asymmetrical operation of large hydro-generator, the eddy current loss of damping bars under the asymmetrical operation of a 1 000 MW hydro-generator was further studied on the basis of establishing two-dimensional electromagnetic field-circuit-motion coupled time-stepping finite element model. The influence of such factors as the stator slotting, magnetic pole rotation and stator current on the eddy Current loss of damping bars were comprehensively considered. The eddy current loss of each damping bar in one magnetic pole under different operating conditions was accurately calculated, and the change rule of eddy current loss was analyzed. And thus, the influence of the connection mode of damping system as well as the radius and material of damping bar on the eddy current loss of damPing bars was discussed. The results indicate that the eddy current loss of last damping bar along the rotation direction is the largest, and the structure parameters of damping system have greater influence on the distribution of eddy current loss of damping bars.