125WVA脉冲发电机组振动原因分析

Vibration Analysis and On-site Dynamic Balance for a 125MVA Pulsed Motor-generator

一台125MVA脉冲发电机组在更换其2000kW异步拖动电动机转子线圈后,当机组加速至接近1800r/min时电动机剧烈振动。几次在电动机转子两中心环上配重均无效果。经分析认为振动未消除的原因是转子滑环端外伸太长。在该端部进行配重后,整台机组的振动情况完全达到了振动要求,最大的座振峰峰值在一阶临界转速时(1800r/min)小于35μm,在2990r/min时小于25μm。此次机组现场动平衡不仅保证了机组的安全运行,也可作为类似的具有较长外伸端轴系动平衡的参考。

After the rotor windings of a 2000kW asynchrony motor were displaced, our 125MVA pulsed Motor-generator set vibrated seriously as it sped up to near 1800r/min. After counterweighing the motor rotor on its center rings several times, the motor vibration was still serious. Analysis shows the reason is that the shaft extension with slip ring of the motor rotor is very long, and a little unbalanced mass on that part should cause severe vibration. After counterweighing on the plate assembled on the shaft extension end, the vibration of the whole set can meet the requirements of operation condition. The maximum vibration peak-to-peak amplitudes for bearng stands are less than 35μm under the first order critical speed of 1800 r/min and less than 25μm under 2980 r/min. The on-site dynamic balance can ensure operation safety of this M-G set, and also that method can be considered as a valuable reference for dynamic balance of those shaft systems with long extensions.