水轮发电机, 电磁力, 动态偏心, 幅频特性

The influence of the nonlinear electromagnetic forces and mass eccentric forces on the dynamic characteristics of the hydro-generator rotor was analyzed. The electromechanical coupling vibration model of the system was established, in which the nonlinear electromagnetic force of eccentricity rotor was obtained by using analytical method. This model was simplified to a single degree-of-freedom system by means of complex variable function. The stationary solution of system was solved by harmonic balance method, and the amplitude-frequency response was presented. The results show that electromagnetic vibration of hydropower generator rotors exhibits nonlinear characteristics, including the jumping phenomenon of amplitude-frequency curve and the obvious soft characteristics.