关键词: 涡带工况, 短时傅里叶变换, 轴心轨迹, 水轮机

Abstract: 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 analysis are introduced in details. 

Key words: vortex zone case, short-time Fourier Transform, shaft core orbits, hydraulic turbines