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针对非线性系统的特点,区别于以往对线性系统使用的时域、频域定性分析法,用分形维数定量刻画系统运行状态。运用非线性动力学理论,通过相空间重构选取延迟时间为18,嵌入维数为1到25,计算了风机失速前后压力信号的关联维数。研究发现关联维数由失速前的1.428下降到失速后的1.198。研究结果表明关联维数对失速信号是敏感的,可以用作判断风机失速的特征量。
According to the characteristics of nonlinear system, it is different from the qualitative analysis methods of time domain and frequency domain used in linear systems in the past. The fractal dimension is used to quantitatively describe the operating status of the system. Using the nonlinear dynamics theory, the correlation dimension of the pressure signal before and after fan stall is calculated by choosing the delay time of 18 and the embedding dimension of 1 to 25 through phase space reconstruction. The study found that the correlation dimension decreased from 1.428 before stalling to 1.198 after stalling. The results show that the correlation dimension is sensitive to the stall signal and can be used as a feature to judge the fan stall.