基于短时傅里叶变换的水轮机涡带工况识别

在对水轮机运行区划分过程中存在着涡带负荷区识别问题,为此开展了专项研究。针对水轮机从空载至满负荷连续升负荷过程中的水导摆度信号,采用高斯窗口函数进行加窗傅里叶变换分析。分析结果表明,采用加窗傅里叶变换这一手段可以精确确定涡带运行区的运行范围,同时根据升负荷过程中主频涡带频率成分出现的先后顺序,将涡带负荷区划分为涡带生成区、强涡带区和涡带消亡区,并对不同区域内涡带影响下的轴心轨迹特点进行了分析。对分析背景、分析方法以及实例分析过程作了比较详细的介绍。

Identification of vortex zone operation of hydraulic turbine based on short-time Fourier Transform

A research is conducted on the identification of the vortex zone in the demarcation of the operation zone of hydraulic turbine. Windowed Fourier Transform analysis with Gaussian window function is carried out for the water guide swing signal in the process of continuous load rise from no-load to full load. The results show that Windowed Fourier Transform is able to accurately identify the operation zone of vortex. The vortex load zone could be divided into vortex generation zone, strong vortex zone and vortex diminishing zone according to the occurrence order of the frequency component of the main vortex in the process of load rise, and the shaft orbits under the effect of vortex in different zones are analyzed. The background, method and process of the a-nalysis are introduced in details.