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Time-domain Dynamic-performanceimprovement Method for Pulse-width-modulated DC-DC Converters Based on Eigenvalue and Eigenvector Sensitivity
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作者 Hong Li Zexi Zhou +1 位作者 Jinchang Pan Qian Liu 《Chinese Journal of Electrical Engineering》 CSCD 2023年第1期104-119,共16页
For pulse-width modulated(PWM)DC-DC converters,the input voltage fluctuation and load variation in practical applications make it necessary for them to have better dynamic performance to meet the regulation requiremen... For pulse-width modulated(PWM)DC-DC converters,the input voltage fluctuation and load variation in practical applications make it necessary for them to have better dynamic performance to meet the regulation requirements of the system.The dynamic-performance-improvement method for PWM DC-DC converters is mainly based on indirect dynamic performance indices,such as the gain margin and phase margin.However,both settling time and overshoot in the time domain are important in practical engineering.This makes it difficult for designers to obtain a clear understanding of the time-domain dynamic performance that can be achieved with improved control.In this study,a direct analysis of the time-domain dynamic characteristic of PWM DC-DC converters is performed.A dynamic-performance-improvement method based on eigenvalues and eigenvector sensitivity(E2S-based DPIM)is proposed to directly improve the time-domain dynamic performance index of PWM DC-DC converters.By considering a boost converter with proportional-integral control as an example,an additional virtual inductor current feedback control was designed using the proposed dynamic-performance-improvement method.Simulation and experimental results verify the validity and accuracy of the proposed dynamic-performance-improvement method. 展开更多
关键词 PWM DC-DC converter time-domain dynamic-performance-improvement method eigenvalue and eigenvector sensitivity additional virtual inductor current feedback control
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THE STATE SPACE RECONSTRUCTION TECHNOLOGY OF DIFFERENT KINDS OF CHAOTIC DATA OBTAINED FROM DYNAMICAL SYSTEM 被引量:4
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作者 陈予恕 马军海 刘曾荣 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 1999年第1期82-92,共11页
Certain deterministic nonlinear systems may show chaotic behavior. We consider the motion of qualitative information and the practicalities of extracting a part from chaotic experimental data. Our approach based on a ... Certain deterministic nonlinear systems may show chaotic behavior. We consider the motion of qualitative information and the practicalities of extracting a part from chaotic experimental data. Our approach based on a theorem of Takens draws on the ideas from the generalized theory of information known as singular system analysis. We illustrate this technique by numerical data from the chaotic region of the chaotic experimental data. The method of the singular-value decomposition is used to calculate the eigenvalues of embedding space matrix. The corresponding concrete algorithm to calculate eigenvectors and to obtain the basis of embedding vector space is proposed in this paper. The projection on the orthogonal basis generated by eigenvectors of timeseries data and concrete paradigm are also provided here. Meanwhile the state space reconstruction technology of different kinds of chaotic data obtained from dynamical system has also been discussed in detail. 展开更多
关键词 nonlinear chaotic data embedding space matrix eigenvalue and eigenvector state space reconstruction
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Efficient Anomalous Forcings for Linear Problems
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作者 李志锦 纪立人 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 1994年第4期436-446,共11页
For linear forcing problems, a method is developed to provide a set of forcing modes which form a complete orthonormal basis for the finite-time response to steady forcing in the energy inner product space. The forcin... For linear forcing problems, a method is developed to provide a set of forcing modes which form a complete orthonormal basis for the finite-time response to steady forcing in the energy inner product space. The forcing modes are found by calculating eigenvectors of a positive definite and symmetric matrix determined from given equations of motion. The amplitude of responses to forcing modes is given in terms of the associated eigenvalues. This method is used in a nondivergent barotropic model linearized about the 300 hPa zonally-varying climatological flow both for northern summertime and wintertime. The results show that the amplitude of response varies considerably with different forcing modes. Only a few of forcing modes associated with the leading eigenvalues, called efficient forcing mode, can excite significant response. The efficient forcing modes possess highly localized spatial structure with wavetrain appearance. Most of the efficient forcings are located to the south of regions of the jet cores. The forcings located over polar regions are also efficient. In addition, the response is larger in wintertime than in summertime for a given forcing. 展开更多
关键词 Generalized eigenvalue and eigenvector Strength factor of response Efficient forcing
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A Novel Perturbative Iteration Algorithm for Effective and Efficient Solution of Frequency-Dependent Eigenvalue Problems
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作者 Rongming Lin 《Advances in Applied Mathematics and Mechanics》 SCIE 2012年第3期325-339,共15页
Many engineering structures exhibit frequency dependent characteristics and analyses of these structures lead to frequency dependent eigenvalue problems.This paper presents a novel perturbative iteration(PI)algorithm ... Many engineering structures exhibit frequency dependent characteristics and analyses of these structures lead to frequency dependent eigenvalue problems.This paper presents a novel perturbative iteration(PI)algorithm which can be used to effectively and efficiently solve frequency dependent eigenvalue problems of general frequency dependent systems.Mathematical formulations of the proposed method are developed and based on these formulations,a computer algorithm is devised.Extensive numerical case examples are given to demonstrate the practicality of the proposed method.When all modes are included,the method is exact and when only a subset of modes are used,very accurate results are obtained. 展开更多
关键词 Frequency dependent eigenvalue problem structural vibration computer algorithm damped structural vibration perturbative iteration eigenvalue and eigenvector sensitivity
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Bounds of Spectral Radii of Weighted Trees 被引量:3
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作者 杨华中 胡冠章 洪渊 《Tsinghua Science and Technology》 SCIE EI CAS 2003年第5期517-520,共4页
Graphs for the design of networks or electronic circuits are usually weighted and the spectrum of weighted graphs are often analyzed to solve problems. This paper discusses the spectrum and the spectral radii of tree... Graphs for the design of networks or electronic circuits are usually weighted and the spectrum of weighted graphs are often analyzed to solve problems. This paper discusses the spectrum and the spectral radii of trees with edge weights. We derive expressions for the spectrum and the spectral radius of a weighted star, together with the boundary limits of the spectral radii for weighted paths and weighted trees. The analysis uses the theory of nonnegative matrices and applies the 'moving edge' technique. Some simple examples of weighted paths and trees are presented to explain the results. Then, we propose some open problems in this area. 展开更多
关键词 weighted trees graph eigenvalue and eigenvector graph spectrum and spectral radius
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