电气技术2026，Vol.27Issue(2)：13-24,12.
汽轮发电机组轴系弯振模态及临界转速影响因素分析
Analysis of the lateral vibration modes and critical speed factors of steam turbine generator shaft systems
摘要
Abstract
The operation of steam turbine generator shaft systems near critical speeds can induce resonant vibrations,compromising operational safety and stability.While existing studies have extensively investigated the lateral vibration critical speeds of individual rotors or the entire shaft system,the relationship between the critical speeds of constituent rotors and the integrated shaft system remains underexplored.Here,a 600 MW turbine-generator shaft system is examined by first establishing a transfer matrix model and a three-dimensional finite element model without support bearings to derive its inherent bending modes.Subsequently,finite element analysis is employed to elucidate the correlation between the critical speeds and modal shapes of the fully supported shaft system and those of its individual rotors.Furthermore,the influence of bearing oil film stiffness on the shaft system's critical speeds is systematically evaluated.Findings reveal that the first six modal shapes of the shaft system are predominantly governed by the modes of the individual rotor whose critical speed is closest to,yet lower than,the corresponding shaft system critical speed.Notably,the fifth and sixth modes exhibit coupled vibrations involving this rotor and its adjacent counterparts.Increasing the oil film stiffness of a rotor's bearings selectively elevates the critical speeds of shaft system modes associated with that rotor,while leaving other modes largely unaffected.These insights provide a foundational framework for optimizing the design and vibration monitoring of large-scale steam turbine generator shaft systems.关键词
汽轮发电机组/轴系/弯振/临界转速/油膜刚度Key words
steam turbine generator unit/shaft system/lateral vibration/critical speed/oil film stiffness引用本文复制引用
乔迪,李娟,杨俊杰..汽轮发电机组轴系弯振模态及临界转速影响因素分析[J].电气技术,2026,27(2):13-24,12.基金项目
国家自然科学基金项目(51477010) （51477010）
