水轮发电机转子偏心引起的非线性电磁振动

由于机械和电磁相互耦合,水轮发电机的电磁振动具有强非线性特征。根据不平衡磁拉力与转子偏心的非线性函数关系,通过简化的各向同性的单圆盘转子系统,建立了水轮发电机转子电磁振动的非线性系统。利用非线性振动理论的多尺度方法,从理论上分析了该系统强迫振动的稳态响应,进而研究了水轮发电机转子偏心引起的电磁振动。研究发现不平衡磁拉力使系统的涡动频率下降,使运动的中心发生变化;并且会引起两倍转频的振动。最后用模型转子仿真试验的结果验证了这些理论分析的结论。

Nonlinear Electromagnetic Vibrations in Hydro-generators with Eccentric Rotors

Electromagnetic vibration in hydro-generator is endowed with nonlinear characteristic due to the mechanic and electromagnetic coupling. According to nonlinear relation of unbalanced magnetic pull with respect to rotor eccentricity,a nonlinear system represented by a symmetrical disk is set up to express electromagnetic vibrations of hydro-generator rotors,the steady-state responses of forced vibrations of the nonlinear system are analyzed theoretically by the method of multiple scales,thus the electromagnetic vibrations of hydro-generators with eccentric rotors is investigated further. The result indicates that the unbalanced magnetic pull declines the critical speed of a rotor,changes center of motion,and causes vibration of twice operating speed,and the conclusions are verified by a simulating test.