320kA系列预焙铝电解槽槽电压波动的频谱解析  

Spectral analysis of cell voltage fluctuation in 320 kA pre-baked aluminum reduction cells

作　　者：唐骞[1,2] 周孑民[1] 单峰[1] 李贺松[1] 蒋科进[2] 郭洁[1] 

机构地区：[1]中南大学能源科学与工程学院,湖南长沙410083 [2]中国铝业公司广西分公司电解厂,531400

出　　处：《中南大学学报（自然科学版）》2009年第2期299-304,共6页Journal of Central South University:Science and Technology

基　　金：国家教育部博士点基金资助项目(20010533009)

摘　　要：通过大量收集320kA系列预焙铝电解槽典型槽况下的槽电压波动数据,利用快速傅里叶变换(FFT)以及功率谱(PSD)估计技术提取槽电压波动的特征谱峰。采用参数估计法进行PSD估计,并将槽电压波动的小波包分析结果和频谱分析结果进行比较。研究结果表明:不同的参数估计法得到趋于一致的频谱分析结果,正常槽只有1个尖锐谱峰,对应于阳极下熔融氧化铝涌动的特征峰,其他故障槽都有2个特征谱峰,即1个主峰和1个次峰,碳渣槽的主峰仍然对应着阳极下熔融氧化铝涌动特征峰,次峰对应悬浮碳渣的涌动特征峰;铝液波动槽主峰对应铝液波动特征峰,次峰对应着熔融氧化铝涌动的特征峰;频谱分析相对于小波包分析具有算法简单、耗时少、物理意义明确等特点,在槽况在线诊断系统的大规模推广中具有优势。An awful lot of data of cell voltage fluctuation under typical working conditions were collected, and a method based on fast fourier transform （FFT） and power spectral density （PSD） estimation was put forward to extract the spectral characteristics of cell voltage. Parametric methods were employed in PSD estimation. Spectral analysis was also compared with wavelet packet analysis. The results reveal that spectra obtained by different parametric methods are similar. The spectra of normal cells＇ voltage have only one noticeable lobe due to fluctuation of molten alumina at anodes, while spectra of other abnormal cells have one mainlobe and one sidelobe. In cells with carbon in bath the spectral mainlobe of cell voltage is still due to the fluctuation of molten alumina at anodes and the sidelobe is due to the fluctuation of carbon in bath; in ceils with metal pad wave, the spectral mainlobe is due to metal pad waving and the sidelobe is still due to the fluctuation of molten alumina at anodes. Compared with wavelet packet analysis, spectral analysis is simpler and takes less time in calculation, which is a big merit in the large-scale application of online diagnosis systems of working conditions in aluminum reduction cells.

关 键 词：铝电解槽 电压波动 FFT 频谱分析 PSD估计 铝液波动 小波包 

分 类 号：TF821[冶金工程—有色金属冶金] TP391[自动化与计算机技术—计算机应用技术]