汽轮发电机组轴系扭振模型参数识别方法

摘要

扭振在线监测和保护设备的扭应力分析精度取决于汽轮发电机组轴系扭振模型与实际轴系在扭振固有特性上的一致性.然而,在模化过程中模型的刚度往往容易出现误差,从而影响扭振分析的准确性.为了估算出模型的扭转刚度参数并消除其扭振固有特性误差,提出了一种通过建立刚度参数微增量与模型固有特性变化量之间的关系方程,求解刚度参数调整量的参数识别方法.经过反复迭代,调整后模型的扭振固有特性可与实测结果非常接近,从而保证扭振应力分析的准确性.%The precision of the torsional stress analysis for torsional vibration online monitoring and protection depends on the similarity of the inherent torsional vibration characteristics between the torsional vibration model and the actual turbine-generator shafts.However,errors are often produced in the stiffness parameters during the modeling process,which affects the precision of the torsional vibration analysis.In order to estimate the stiffness parameters of the model and eliminate the error of the inherent torsional vibration characteristics,a parameter estimation method for obtaining the adjustment of the stiffness parameters is proposed by establishing the relational equation between the micro-increment of the stiffness parameters and the changes of the inherent characteristics.Through repeated iteration,the inherent characteristics of the adjusted model can be very close to the torsional vibration test results,and thus ensures the precision of the torsional vibration stress analysis.