非同期并列时汽轮发电机组轴系弯扭耦合振动分析

Coupled Flexural and Torsional Vibrations Analysis of Turbine Generator Shaft Systems Caused by Asynchronous Juxtaposition

将逐步积分法的思想与传统传递矩阵法相结合,提出了增量传递矩阵方法。基于多段集中质量模型和增量传递矩阵法,并结合Riccati法,建立了汽轮发电机组轴系弯扭耦合振动瞬态响应求解模型。利用该方法,针对某200MW汽轮发电机组的120°和180°两种非同期并列情况,进行了机组弯扭耦合振动响应特性研究,分析表明:汽轮发电机组的120°和180°两种非同期并列情况下的弯振和扭振响应特性基本相似;非同期并列主要激发出工频和前两阶固有频率扭振,弯振除工频主分量外,第一阶固有频率也被激发出来;180°非同期并列时的暂态电磁力矩峰值比120°非同期并列时低,相应的扭振和扭矩响应也小于后者。

An increment transfer matrix method based on step-by-step integration method and traditional transfer matrix method was put forward. Combined with Riccati method, the increment transfer matrix method was used in a multi-mass model. And matrix equations calculating the responses of coupled flexural and torsional vibrations were deduced. The responses properties of coupled vibrations for 120° and 180°asynchronous juxtaposition of 200MW turbine-generator set were analyzed. The results show that the responses properties of flexttral and torsional vibrations caused by 120° asynchronous juxtaposition are similar to that of 180°asynchronous juxtaposition. When the fault happened, Former two steps inherence frequencies and whirl speed frequency of torsion are excited. And the first step inherence frequencies of flexural vibration are also excited besides whirl speed frequency. Transient electromagnetism moment peak, torsional and torsional moment responses caused by 180° asynchronous juxtaposition are lower than that of 120° asynchronous juxtaposition.