Simulation of the steady state of oscillators in the time domain

Author(s):  
H. G. Brachtendorf ◽  
K. Bittner ◽  
R. Laur
2003 ◽  
Vol 13 (11) ◽  
pp. 3395-3407 ◽  
Author(s):  
F. A. SAVACI ◽  
M. E. YALÇIN ◽  
C. GÜZELIŞ

In this paper, nonlinearly coupled identical Chua's circuits, when driven by sinusoidal signal have been analyzed in the time-domain by using the steady-state analysis techniques of piecewise-linear dynamic systems. With such techniques, it has become possible to obtain analytical expressions for the transfer functions in terms of the circuit parameters. The proposed system under consideration has also been studied by analog simulations of the overall system on a hardware realization using off-the-shelf components as well as by a time-domain analysis of the synchronization error.


2015 ◽  
Vol 35 (1Sup) ◽  
pp. 58-64
Author(s):  
Yulieth Jimenez ◽  
Cesar Duarte ◽  
Johann Petit ◽  
Jan Meyer ◽  
Peter Schegner ◽  
...  

<p class="Abstractandkeywordscontent"><span lang="ES-CO"><span><span><span style="font-family: OptimaLTStd-DemiBold; font-size: 10pt; color: #231f20; font-style: normal; font-variant: normal;"><span style="font-family: OptimaLTStd; font-size: 9pt; color: #231f20; font-style: normal; font-variant: normal;">Smart Grid paradigm promotes advanced load monitoring applications to support demand side management and energy savings. Recently, considerable attention has been paid to Non-Intrusive Load Monitoring to estimate the individual operation and power consumption of the residential appliances, from single point electrical measurements. This approach takes advantage of signal processing<span style="font-family: OptimaLTStd; font-size: 9pt; color: #231f20; font-style: normal; font-variant: normal;"> in order to reduce the hardware effort associated to systems with multiple dedicated sensors. Discriminative characteristics of the <span style="font-family: OptimaLTStd; font-size: 9pt; color: #231f20; font-style: normal; font-variant: normal;">appliances, namely load signatures, could be extracted from the transient or steady state electrical signals. In this paper the effect of <span style="font-family: OptimaLTStd; font-size: 9pt; color: #231f20; font-style: normal; font-variant: normal;">impact factors that can affect the steady state load signatures under realistic conditions are investigated: the voltage supply distortion, <span style="font-family: OptimaLTStd; font-size: 9pt; color: #231f20; font-style: normal; font-variant: normal;">the network impedance and the sampling frequency of the metering equipment. For this purpose, electrical measurements of several <span style="font-family: OptimaLTStd; font-size: 9pt; color: #231f20; font-style: normal; font-variant: normal;">residential appliances were acquired and processed to obtain some indices in the time domain. Results include the comparison of<br /><span style="font-family: OptimaLTStd; font-size: 9pt; color: #231f20; font-style: normal; font-variant: normal;">distinct scenarios, and the evaluation of the suitability and discrimination capacity of the steady state information.</span></span></span></span></span></span></span><br style="font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px;" /><br class="Apple-interchange-newline" /></span></span></span></span></p>


2020 ◽  
Author(s):  
Keno L. Krewer ◽  
Mischa Bonn

AbstractDifficulties assessing and predicting the current outbreak of the severe acute respiratory syndrome coronavirus 2 can be traced, in part, to the limitations of a static description of a dynamic system. Fourier transforming the time-domain data of infections and fatalities into the frequency domain makes the dynamics easily accessible. Defining a quantity like the “case fatality” as a spectral density allows a more sensible comparison between different countries and demographics during an ongoing outbreak. Such a case fatality informs not only how many of the confirmed cases end up as fatalities, but also when. For COVID-19, knowing this time and using the entire case fatality spectrum allows determining that an outbreak had entered a steady-state (most likely its end) about 14 days before this is obvious from time-domain data. The lag between confirmations and deaths also helps to estimate the effectiveness of contact management: The larger the lag, the less time the average confirmed person had to infect people before quarantine.


2011 ◽  
Vol 179-180 ◽  
pp. 1435-1440
Author(s):  
Ying Chen ◽  
Xiang Jie Chen

When the TCSC steady-state operation, the thyristor turn-on and turn-off time is definite, the changing for TCSC electric capacity voltage and thyristor electric current is with the periodicity and symmetry.Thyristor controlled series compensation technology is fixed series compensation technology foundation, which is meet the needs for adaptation electrical power system operation control developing. With changes the triggering angle for thyristor suitably, then can realize the TCSC equivalent reactance fast, continuously and adjusts smoothly, provides the controllable series compensation for the system, as to achieve increases the system transmitting capacity, enhance the transition condition stability, the damping power oscillation, and the purpose for improvement system tidal current distribution. Although in the entire time axis, obtains the analytic expression for TCSC running status variable is difficulty, but as long as had determined the analytic expression for various electrical quantity in a power frequency cycle, according to the stable state movement's symmetry and periodicity, we can determine the steady state profile that in the entire time axis, and then analyses the TCSC electric circuit’s steady-state characteristic with the time domain computation method. In this paper, topological analysis for TCSC operation established by formula, and then carries on the time domain partition to the TCSC electric circuit solution, finally obtains the steady state fundamental frequency impedance model for TCSC. This paper steady-state characteristic analysis is mainly carries on the topological analysis method to the TCSC main circuit, then establishes the stable state base frequency impedance model for TCSC, and analyses the resonance question for TCSC simultaneously. Then studies TCSC the steady- state characteristic, and with modeling and simulation on them to do further research and analysis, and utilizes the solution method for transformation territory, namely applies the Laplace transform solution equation of state. Thus can be obtained the zero-input response and zero status response formula for system.


2020 ◽  
Vol 18 ◽  
pp. 53-73
Author(s):  
Konstantin Pasche ◽  
Fabian Ossevorth ◽  
Ralf T. Jacobs

Abstract. Reverberation chambers show transient behaviour when excited with a pulsed signal. The field intensities can in this case be significantly higher than in steady state, which implies that a transient field can exceed predefined limits and render test results uncertain. Effects of excessive field intensities of short duration may get covered and not be observable in a statistical analysis of the field characteristics. In order to ensure that the signal reaches steady state, the duration of the pulse used to excite the chamber needs to be longer than the time constant of the chamber. Initial computations have shown that the pulse width should be about twice as long as the time constant of the chamber to ensure that steady state is reached. The signal is sampled in the time domain with a sampling frequency according to the Nyquist theorem. The bandwidth of the input signal is determined using spectral analysis. For a fixed stirrer position, the reverberation chamber, wires, connectors, and antennas can jointly be considered as a linear time-invariant system. In this article, a procedure will be presented to extract characteristic signal properties such as rise-time, transient overshoot and the mean value in steady state from the system response. The signal properties are determined by first computing the envelope of the sampled data using a Hilbert transform. Subsequent noise reduction is achieved applying a Savitzky–Golay filter. The point where steady state is reached is then computed from the slope of the envelope by utilising a cumulative histogram. The spectral analysis is not suitable to examine the transient behaviour and determine the time constants of the system. These constants are computed applying the method of Prony, which is based on the estimation of a number of parameters in a sum of exponential functions. An alternative to the Prony Method is the Time-Domain Vector-Fit method. In contrast to the first mentioned variant, it is now also possible to determine the transfer function of the overall RC system. Differences and advantages of the methods will be discussed.


1989 ◽  
Vol 56 (1) ◽  
pp. 149-154 ◽  
Author(s):  
T. M. Cameron ◽  
J. H. Griffin

A method is proposed for analyzing the steady-state response of nonlinear dynamic systems. The method iterates to obtain the discrete Fourier transform of the system response, returning to the time domain at each iteration to take advantage of the ease in evaluating nonlinearities there—rather than analytically describing the nonlinear terms in the frequency domain. The updated estimates of the nonlinear terms are transformed back into the frequency domain in order to continue iterating on the frequency spectrum of the steady-state response. The method is demonstrated by solving a problem with friction damping in which the excitation has multiple discrete frequencies.


2012 ◽  
Vol 134 (6) ◽  
Author(s):  
Masoud Kharati Koopaee ◽  
Amir Omidvar

In this study, a simple spectral-finite volume approach for hyperbolic heat conduction problems under periodic surface temperature is presented. In this approach, by choosing only three frequencies from a continuum frequency spectrum of the periodic temperature field, the time dependent governing equation is transformed into the steady state one in the frequency domain. Then, using the finite volume technique, temperature field in the frequency domain for each wave number is obtained. Finally, by transforming back the result to the time domain, the temperature field in the time domain would be obtained. This new method has been validated against some published results and a good agreement has been found. Despite the simplicity of the present method, it is able to accurately predict the temperature distribution in the periodic steady state portion of non-Fourier heat conduction problems subjected to periodic surface temperature.


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