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Transfer function

About: Transfer function is a research topic. Over the lifetime, 14362 publications have been published within this topic receiving 214983 citations. The topic is also known as: system function & network function.


Papers
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Journal ArticleDOI
01 Jun 2021
TL;DR: In this paper, a reduced-order model for all-solid-state batteries (ASSBs) is proposed to calculate the equilibrium potential, overpotentials, and battery voltage in real time.
Abstract: All-solid-state batteries (ASSBs) have been considered as the next generation of lithium-ion batteries. Physics-based models have the advantage of providing internal electrochemical information. To promote physics-based models in real-time applications, in this study, a series of model reduction methods are applied to obtain a reduced-order model (ROM) for ASSBs. First, analytical solutions of the partial differential equations (PDEs) are derived by the Laplace transform. Then, the Pade approximation method is used to convert the transcendental transfer functions into lower order fractional transfer functions. Next, the concentration distributions in electrodes and electrolytes are approximated by parabolic and cubic functions, respectively. Due to the fast calculation of concentration distributions in real time, the equilibrium potential, overpotentials, and battery voltage can now be directly calculated. Compared with the original PDE-based model, the voltage errors of the proposed ROM are less than 2.6 mV. Compared with the voltage response of experimental data, a good agreement can be observed for the ROM under three large C-rates discharging conditions. The calculation time of ROM per step is within 0.2 ms, which means that it can be integrated into a battery management system. The proposed ROM achieves excellent performance and a better tradeoff between model fidelity and computational complexity.

55 citations

Proceedings ArticleDOI
30 Apr 2000
TL;DR: Results of Matlab simulations validate the performance of the proposed method for measuring random jitter, which relies on the extension of a real signal into an analytic signal by utilizing the Hilbert transform.
Abstract: This paper proposes a new method based on analytic signal theory for extracting both instantaneous and RMS sinusoidal jitter from PLL output signals. The method relies on the extension of a real signal into an analytic signal by utilizing the Hilbert transform. Both the theoretical basis and fundamental concepts of the proposed method are explained. A review of conventional testing methods is also presented. Results of Matlab simulations validate the performance of the proposed method for measuring random jitter. The method is further validated by comparing experimental sinusoidal jitter results with those measured with a time interval analyzer.

55 citations

01 Jan 1988
TL;DR: In this paper, the Fourier coefficients of voltage and current are estimated using recursive least squares identification, and the estimates are then used to detect short circuits, and a method for inverse glottal filtering is presented.
Abstract: This thesis consists of four parts, with system identification as the common theme. The first part studies the asymptotic properties of two-dimensional identification methods. In the second part an approach to identification of time varying systems is presented. Part three applies system identification to the problem of transmission line protection. Finally part four deals with input estimation in speech coding.Part I is devoted to system identification in two dimensions. First we study the asymptotic properties of the estimates as the number of data tends to infinity. The main objective is to investigate what happens if the model order also tends to infinity. The focus is on frequency expressions of the extimation variance. The analysis covers both the least squares method for causal models, and the maximum likelihood method for noncausal models.In Part II we study one approach to identification of time varying sytems. The parameter variations are modelled as process noise in a state space model, and identified using adaptive Kalman filtering. A method for adaptive Kalman filtering is derived and analysed. The simulations indicate that this new approach is superior to previous methods based on adjusting the forgetting factor. The improvement is however gained at the price of a significant increase in computational complexity.Part III describes the use of recursive identification in protective relaying. The Fourier coefficients of voltage and current are estimated using recursive least squares identification. The estimates are then used to detect short circuits. The method is evaluated using data generated by the standard program EMTP.In Part IV a method for inverse glottal filtering is presented. The basis of the method is to use a parameterized model of the input signal, i.e. the glottal pulses. The algorithm simultaneously estimates the parameters of the input signal and the parameters of the system transfer function, the vocal tract model. The presentation is restricted to transfer functions of all-pole type.

55 citations

Journal ArticleDOI
TL;DR: This article shows how a non-decimated wavelet packet transform (NWPT) can be used to model a response time series in terms of an explanatory time series, Xt, and produces models to which it can attach physical and scientific interpretations.
Abstract: This article shows how a non-decimated wavelet packet transform (NWPT) can be used to model a response time series, Yt, in terms of an explanatory time series, Xt. The proposed computational technique transforms the explanatory time series into a NWPT representation and then uses standard statistical modelling methods to identify which wavelet packets are useful for modelling the response time series. We exhibit S-Plus functions from the freeware WaveThresh package that implement our methodology. The proposed modelling methodology is applied to an important problem from the wind energy industry: how to model wind speed at a target location using wind speed and direction from a reference location. Our method improves on existing target site wind speed predictions produced by widely used industry standard techniques. However, of more importance, our NWPT representation produces models to which we can attach physical and scientific interpretations and in the wind example enable us to understand more about the transfer of wind energy from site to site.

55 citations

Journal ArticleDOI
TL;DR: In this article, the Cockcroft-Walton voltage multiplier with an arbitrary number of cells is described and the expressions of cut-off frequency, gain and output impedance are given, and module and phase frequency responses are plotted.
Abstract: The description of the small-signal dynamics of the Cockcroft-Walton voltage multiplier is obtained through state-space modeling in discrete time. Its small-signal equivalent circuit is a two-port linear network whose four transfer functions are given in the Z-transform. The main characteristics and general formulae of the multiplier with an arbitrary number of cells are derived. The expressions of cut-off frequency, gain and output impedance are given, and module and phase frequency responses are plotted. >

55 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023351
2022810
2021329
2020421
2019461
2018493