时频分析法在高压水泵启动过程分析中的应用

Application of Time-Frequency Analysis Method to Start-up Process Analysis of High-Pressure Hydraulic Pump

对水泵机组振动信号分析中短时傅立叶变换的时间分辨率和频率分辨率的设定、窗函数的选取进行了研究.以短时傅立叶变换方法为基础分析高压水泵振动信号,克服了单纯采用快速傅立叶变换进行分析的不足.结果表明:用时频分析法对离心式高压水泵的启动过程进行分析不但可以准确确定各频率成份在启动过程中的变化,还可以确定某些外界的干扰信号,为判断水泵运行是否正常和故障原因提供了有力的依据.

The determination of time discrimination and frequency discrimination and the selection of a window function in the short-term Fourier transform(STFT) were discussed to analyze the vibrational signals from a high-pressure hydraulic pump unit. This method based on the STFT overcomes the shortcoming of the fast Fourier transform. The analysis result shows that the application of time-frequency analysis method to the start-up process analysis of centrifugal type of high-pressure hydraulic pumps can not only exactly determine the change of each individual frequency in the process, but also find out some external interfering signals to judge whether a pump is working normally or not and the reason for its fault.