小波降噪及EMD方法在泵房前池水位波动分析中的应用

Application of wavelet de-noising and EMD in analyzing the water level fluctuation in forebay of pump station

为保障机组运行安全,滨海核电厂泵房前池的水面波动有一定的要求。文章通过小波分析方法,选择合适的小波基函数、分解层数及阈值对含噪信号进行降噪处理,并应用于泵房前池波动试验的信号降噪。通过EMD分析方法,将泵房前池的波动信号分解为长周期波动和短周期波动,结果发现前池的波动以长周期波动为主,短周期波动较小,满足泵房取水的安全要求,但从厂址安全角度出发,应评估长周期波动对厂坪标高的影响。

To guarantee the safety of operation, coastal nuclear power plant has requirements on the fluctuation of water levelin the forebay of pump station. Through the wavelet analysis method, we chose suitable wavelet basis function, decompositionorder and threshold value to denoise the noisy signal, and applied it to noise reduction in the fluctuation test of the foreby ofpump station. Adopting the EMD to decompose the signal into long period wave and short period wave, the result shows that thewave in forebay of pump station is dominated by the long period, short period wave is small, which can guarantee the safety ofusing cooling water. While the effects of long period wave on the platform elevation of nuclear power plants should be furtherevaluated from the safety point of the plant.