基于奇异值分解的水轮机空化压力脉动调控方法

Adjustment and control of the hydroturbine’s cavitation pressure pulsation based on singular-value decomposition

为了减小水轮机运行过程中空化、空蚀对效率和出力的影响,合理地分析和提取空化信号对指导水轮机的调控和运行有重要意义。文中提出了一种基于奇异值分解的水轮机空化压力脉动信号提取方法,采用奇异值辨识法对试验测得的压力脉动信号进行分离,分析水轮机产生空化时的压力脉动波形,以提高对空化工况分析的准确性,通过CFD仿真优化,模拟水轮机运行的工况,分析空化现象与压力脉动信号的关系。采用奇异值分解方法对水轮机压力脉动信号进行分离,实现脉动信号的降噪和特征提取。结合PID控制技术和远程检测技术,实现对流量、水位、补气阀开度的智能调控,保障了水轮机组的平稳运行。

In order to reduce the impact of cavitation on the hydroturbine’s efficiency and output,reasonable analysis and extraction should be conducted on the cavitation signal,which is of great significance for the hydroturbine’s adjustment and operation.In this article,a method for extracting the signal of the hydroturbine’s cavitation pressure pulsation based on singular value decomposition is proposed.The method of singular-value identification is adopted to separate the experimentally-measured signal of pressure pulsation,and the analysis is conducted on the waveform of pressure pulsation when the hydroturbine’s goes through the cavitation,in order to get an accurate picture of the cavitation-related working conditions.By means of the CFD technology,the hydroturbine’s operating conditions are simulated,and as a result,the cavitation process becomes more intuitive and clear.The results show that the method of singular-value decomposition helps to separate the signal of the hydroturbine’s pressure pulsation,which will accurately reduce the noise and extract the characteristics of the pulsation signal.Combined with PID control technology and remote detection technology,the intelligent control of flow,water level and valve opening is realized,which ensures the smooth operation of the turbine unit.