针对大型水轮发电机组在暂态运行时,由于暂态径向电磁力、电磁力矩诱发的发水轮发电机组双质量系统横-扭耦合振动进行了分析,建立了描述横-扭耦合振动的双质量系统数学模型,探讨了由于机电参数激励与转子轴系耦合振动的动力学特性。分析结果表明,系统振动具有明显的混沌的特性,横向振动对扭振的影响十分显著,使转子系统扭转角位移的幅值明显增加,最大扭转振动幅值发生于频谱1/2分频处;偏心对振动的影响存在参数极值区,即当偏心值落在这个范围内时,混沌振动的振幅会随偏心剧增,但静偏心对轴系振动特性的影响较小。若电磁参数和机械参数处在影响系统振动的灵敏区域,将诱发机组激烈的混沌振动。
The lateral-torsional coupling vibration of rotor system of a hydro-turbine generator unit caused by transitional electro-magnetic force and moment is studied in this paper. A mathematical model on the lateral-torsional coupling vibration is established. The dynamic characteristics of the system are investigated on the numerical computations. The results show that the vibration of the system is chaotic and the lateral motion has a significant influence on the torsional vibration of the system. The maximum peak amplitude of the vibration takes place at the 1/2 fractal frequency. The influence of the rotating eccentricity on the torsional vibration has an extreme value range within which the vibration will strongly increase. The role of the rest initial eccentricity in the vibration is not important against the dynamic rotating eccentricity. Therefore, if the operation state of the system falls into the sensitive area of the mechanical and electromagnetic parameters, a strong vibration will be induced due to the parametric resonance.