摘要
为提高余热锅炉水位控制精度,研究了其汽包水位噪声的特性,基于EMD(empirical mode decomposition)自适应分频方法,提出采用汽包水位脉动信号的IMF(intrinsic mode functions)分量的能量进行特征频带识别的新方法。先用EMD分解水位信号,然后结合频谱分析对各IMF分量的频带能量进行分析,考虑各分量频段包含信号的物理意义,去除主要干扰因素所对应的IMF分量,提取有用的IMF分量重构得到无干扰成分的水位真实趋势信号,使对汽包水位信号的分析不依赖于工况和参数的影响。对水位纯噪声和2种工况下真实水位提取结果表明,该文提出的方法用于分析非线性不确定的水位信号变化的真实趋势具有较好的效果。
Drum level noise makes influence on level control accuracy of heat recovery steam generators （HRSG） in gas：steam combined cycle. To improve the accuracy and robustness of control system, the nonlinear characteristics of level signals are exploited. Empirical mode decomposition （EMD） is an adaptive frequency band dividing method of signal Through EMD, practical drum level signal is decomposed into a series of IMFs and their spectrum is analyzed. Each IMF component covers specific frequency band. Useful IMFs are selected to reconstruct the true drum level signal without corresponding disturbance. The true level signal is immune to HRSG operating conditions and noise. Under pure level noise and two types circumstances, the experimental results of level signals show, the proposed method is reasonable to extract true level signal and deal with nonlinear level signal of HRSG.
出处
《中国电机工程学报》
EI
CSCD
北大核心
2007年第2期15-19,共5页
Proceedings of the CSEE
基金
国家自然科学基金项目(50505045E0524)~~
关键词
余热锅炉
水位信号
经验模态分解
本征模函数
heat recovery steam generators
drum level
empirical mode decomposition
intrinsic mode functions
