A technique to extract real modes from the identified complex modes is presented in this paper, which enables the normalized real mode shapes, modal masses, and full or reduced mass and stiffness matrices to be obtain...A technique to extract real modes from the identified complex modes is presented in this paper, which enables the normalized real mode shapes, modal masses, and full or reduced mass and stiffness matrices to be obtained. The theoretical derivation of the method is provided in detail. An 11-DOF vibration system is used to validate the algorithm, and to analyze the effects of the number of modes utilized and measurement DOFs on the extraction results. Finally, the method is used to extract real modes from both experimental modal analysis and operational modal analysis.展开更多
文摘A technique to extract real modes from the identified complex modes is presented in this paper, which enables the normalized real mode shapes, modal masses, and full or reduced mass and stiffness matrices to be obtained. The theoretical derivation of the method is provided in detail. An 11-DOF vibration system is used to validate the algorithm, and to analyze the effects of the number of modes utilized and measurement DOFs on the extraction results. Finally, the method is used to extract real modes from both experimental modal analysis and operational modal analysis.
文摘该文将结构学领域用于分析建筑或机械结构振动特性的多参考点复指数(poly-reference complex exponential,PRCE)法引入电力系统,实现低频振荡辨识。该方法基于多通道信号,构造脉冲序列的自回归模型(autoregressive model,AR model),运用LQ分解,求解其自回归系数,再求解由自回归系数构成的矩阵多项式的根,得到频率和阻尼比,进而求得系统的模态矩阵。该文介绍了PRCE法在电力系统低频振荡模式辨识中的原理,16机系统的仿真结果验证了PRCE方法的有效性和正确性;与总体最小二乘–旋转不变技术参数估计(total least squares-estimation of signalparameters via rotational invariance techniques,TLS-ESPRIT)方法、随机子空间(stochastic subspace identification,SSI)方法的对比表明,该方法辨识结果在辨识精度、效率上表现得更好。最后,基于四川电网实测数据验证了PRCE方法的有效性。
基金The National High Technology Research and Development Program of China(2006AA110102)The Fundamental Research Funds for the Central Universities(CDJXS11110005)
