为提高目前电力系统次同步振荡参数辨识精度,提出一种基于随机减量技术RDT(random decrement technique)和稀疏时域STD(sparse time domain)算法相结合的辨识方法。利用RDT对输入信号进行处理,提取自由衰减时域信号。然后通过STD算法计...为提高目前电力系统次同步振荡参数辨识精度,提出一种基于随机减量技术RDT(random decrement technique)和稀疏时域STD(sparse time domain)算法相结合的辨识方法。利用RDT对输入信号进行处理,提取自由衰减时域信号。然后通过STD算法计算得到振荡模态参数。仿真算例和实测算例的结果表明,该方法可以有效地辨识出次同步振荡的模态参数,可以用于辨识电力系统次同步振荡,为抑制次同步振荡的设计奠定了基础。展开更多
In view of the feature of flight flutter test data with atmospheric turbulence excitation, a method which combines wavelet transformation with random decrement technique for identifying flight flutter modal parameters...In view of the feature of flight flutter test data with atmospheric turbulence excitation, a method which combines wavelet transformation with random decrement technique for identifying flight flutter modal parameters is presented. This approach firstly uses random decrement technique to gain free decays corresponding to the acceleration response of the structure to some non-zero initial conditions. Then the continuous Morlet wavelet transformation of the free decays is performed; and the Parseval formula and residue theorem are used to simplify the transformation. The maximal wavelet transformation coefficients in different scales are searched out by means of band-filtering characteristic of Morlet wavelet, and then the modal parameters are identified according to the relationships with maximal modulus and angle of the wavelet transform. In addition, the condition of modal uncoupling is discussed according to variation trend of flight flutter modal parameters in the flight flutter state. The analysis results of simulation and flight flutter test data show that this approach is not only simple, effective and feasible, but also having good noise immunity.展开更多
阻尼比是结构动力分析的重要参数之一,阻尼比的准确取值是结构动力响应准确分析的前提.由于阻尼机理非常复杂,对阻尼比的取值一般通过实测得到.传统的模态参数识别方法同时需要已知激励和响应信号,但对实际建筑结构,激励施加存在困难....阻尼比是结构动力分析的重要参数之一,阻尼比的准确取值是结构动力响应准确分析的前提.由于阻尼机理非常复杂,对阻尼比的取值一般通过实测得到.传统的模态参数识别方法同时需要已知激励和响应信号,但对实际建筑结构,激励施加存在困难.探讨了基于环境激励下的模态识别方法,利用环境激励下的结构振动响应数据,探讨了采用随机减量法和ITD(Ibrahim Time Domain)法相结合,有效地识别实际建筑结构的模态参数的方法.工程实例识别结果表明,该方法不仅能准确识别出结构的模态频率,也能相对准确地得到结构的模态阻尼比.展开更多
文摘为提高目前电力系统次同步振荡参数辨识精度,提出一种基于随机减量技术RDT(random decrement technique)和稀疏时域STD(sparse time domain)算法相结合的辨识方法。利用RDT对输入信号进行处理,提取自由衰减时域信号。然后通过STD算法计算得到振荡模态参数。仿真算例和实测算例的结果表明,该方法可以有效地辨识出次同步振荡的模态参数,可以用于辨识电力系统次同步振荡,为抑制次同步振荡的设计奠定了基础。
基金National Natural Science Foundation of China(60134010)
文摘In view of the feature of flight flutter test data with atmospheric turbulence excitation, a method which combines wavelet transformation with random decrement technique for identifying flight flutter modal parameters is presented. This approach firstly uses random decrement technique to gain free decays corresponding to the acceleration response of the structure to some non-zero initial conditions. Then the continuous Morlet wavelet transformation of the free decays is performed; and the Parseval formula and residue theorem are used to simplify the transformation. The maximal wavelet transformation coefficients in different scales are searched out by means of band-filtering characteristic of Morlet wavelet, and then the modal parameters are identified according to the relationships with maximal modulus and angle of the wavelet transform. In addition, the condition of modal uncoupling is discussed according to variation trend of flight flutter modal parameters in the flight flutter state. The analysis results of simulation and flight flutter test data show that this approach is not only simple, effective and feasible, but also having good noise immunity.
文摘阻尼比是结构动力分析的重要参数之一,阻尼比的准确取值是结构动力响应准确分析的前提.由于阻尼机理非常复杂,对阻尼比的取值一般通过实测得到.传统的模态参数识别方法同时需要已知激励和响应信号,但对实际建筑结构,激励施加存在困难.探讨了基于环境激励下的模态识别方法,利用环境激励下的结构振动响应数据,探讨了采用随机减量法和ITD(Ibrahim Time Domain)法相结合,有效地识别实际建筑结构的模态参数的方法.工程实例识别结果表明,该方法不仅能准确识别出结构的模态频率,也能相对准确地得到结构的模态阻尼比.
