某混流式水轮发电机组现场稳定性试验及振动保护策略研究

Research on Field Stability Test of Francis Hydropower Generating Unit and Vibration Protection Strategy

为掌握某混流式水轮发电机组的运行稳定性情况,对该机组进行现场稳定性试验。从测试数据时域频谱分析结果可看出,机组在80～120 MW负荷工况运行时,上导摆度、水导摆度及顶盖振动与尾水压力脉动有相同的频率特性,且振动摆度明显增大,主要由低频涡带引起。根据变负荷试验数据将该机组在试验水头下的运行区域划分为小负荷工况区、涡带工况区和稳定工况区,并根据试验机组的结构特性及运行特性,结合现场试验数据,提出了该机组振动保护控制策略,为机组安全运行提供依据和保障。

In order to master the operation stability of Francis turbine-generator unit,the stability of the unit was tested.From the analysis results of time domain and spectrum diagram for test data,It can be seen that the swing of upper guide bearing and turbine bearing,vibration of tectum which increased significantly has the same frequency characteristics with pressure fluctuation in the draft tube when the unit run at the operating region which was in the range of 80 MW and 120 MW load,and it was caused by low-frequency vortex zone.The unit＇s operating range,such as small load vibration zone,vortex zone and large load stability zone were divided according to the variable load test results under the test head.According to the structural characteristics and operating characteristics of the test unit,the vibration protection strategy was proposed to ensure the safe operation of the unit based on the field test data.