基于EWT和修正Morris法的抽水蓄能电站主进水阀自激振动研究

Self-excited vibration of pumped storage power station’s main inlet valve based on EWT and modified Morris method

为研究主进水阀的自激振动机理,首先基于瞬变流理论建立抽水蓄能电站过水系统精细化数值模型,计算得到上游测压管水位随时间的变化曲线。然后采用经验小波变换法(EWT)对电站采集的主进水阀自激振动信号和数值仿真信号进行特征提取和频谱分析,以验证数值模型的正确性。接着引入修正Morris参数筛选法,从众多性能参量中探明管道长度、管道的水击波速和主进水阀阀门间隙为敏感参量。最后,针对敏感参量设置3个方案分别进行数值模拟,以研究其对自激振动过程的具体影响。结果表明:主进水阀阀门间隙对自激振动的振幅增长速率及幅值影响大,但对系统的周期影响小;管道的水击波速及长度对自激振动的振幅增长速率、幅值以及周期影响极大。

In order to study self-excited vibration mechanism of the main inlet valve of a pumped storage power station,its waterflowing system’sprecision numerical simulation model was established based on the transient flow theory to obtain the variation curve of water level of the upstream pressure measuring pipe with time by calculation.The empirical wavelet transform(EWT)method was used to do feature extraction and spectral analysisfor self-excited vibration signals and simulatedonesof the main inlet valve,and verify the correctness of the numerical model.The modified Morris method was introduced to find pipeline length,pipelinewater hammer wave velocity and valve clearance of main inlet valve being sensitive parameters invarious performance ones.Finally,aiming at sensitive parameters,3 schemes were set to do numerical simulation,respectively and study their specific effects on self-excited vibration process.The results showedthat main inlet valve clearance has a large influence on self-excited vibration amplitude and its growth rate,but has little effect on system’s period;pipeline water hammer wave velocity and pipeline length have great influence on self-excited vibration amplitude,its growth rate and system’s period.