汽轮发电机转子匝间短路时转子振动特性分析

考虑了实际运行的汽轮发电机普遍存在的偏心状态,对转子匝间短路引起的转子振动特性进行了机电耦联交叉特性分析。首先分析转子匝间短路时的气隙磁场变化特征,计算得到定转子间的气隙磁导和气隙磁场能的解析式,然后得到作用于转子的不平衡磁拉力的表达式,最终得到转子径向振动特征。该不平衡磁拉力不仅会增加转子工频振动,同时也会引起倍频和高频振动。并实际测试了SDF-9型模拟发电机匝间短路时转子振动信号,与理论分析结果基本吻合。

Analysis of rotor vibration characteristic for turbine generator rotor winding inter-turn short circuit fault

Considering the prevailing eccentricity state of the practical operated turbine generator,the mechanical and electrical cross-coupling analysis was carried on the vibration characteristic of rotor which was caused by rotor winding inter-turn short circuit.Firstly we calculated air-gap magnetomotive force distribution,air-gap magnetic permeability and air-gap magnetic field energy.Then the frequency characteristic of imbalance magnetic pull acting on rotor was found out.Finally we got the rotor vibration characteristic.The imbalance magnetic pull would not only increase rotor fundamental frequency vibration,but also cause double-times frequency and high-frequency vibration.Using practically acquired rotor vibration data on the spot of SDF-9 generator,the results of verification show that the analysis is correct.