Grounding system modeling in EMTP/ATP based on its frequency response

2005 ◽  
Author(s):  
M. Vargas ◽  
D. Rondon ◽  
J. Herrera ◽  
J. Montana ◽  
D. Jimenez ◽  
...  
Keyword(s):  
Frequency Response ◽  
System Modeling ◽  
Grounding System

IN VIVO EVALUATION OF THE HUMAN CAROTID ARTERY COMPLEX ELASTIC MODULUS

2006 ◽  
Vol 06 (02) ◽  
pp. 189-208
Author(s):  
GRAF SEBASTIÁN ◽  
ZÓCALO YANINA ◽  
PESSANA FRANCO ◽  
BIA DANIEL ◽  
GAMERO LUCAS ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Frequency Response ◽  
Arterial Wall ◽  
Complex Modulus ◽  
System Modeling ◽  
In Vivo Evaluation ◽  
Viscoelastic Parameters ◽  
Before And After

The arterial wall dynamics evaluation requires the assessment of its frequency-response. The aim was to apply an original methodology, to evaluate the arterial wall pressure-diameter frequency-response and elastic complex modulus, of human in vivo and in vitro common carotid arteries (CCA). CCA pressure, diameter and wall thickness were recorded. In vitro recordings were performed using pressure microtransducer (Konigsberg) and sonomicrometry, in 14 CCA segments (from donors). The in vivo recordings were obtained non-invasively by tonometry and mode-B echography in 10 normotensive patients, and in 10 hypertensive patients before and after 3 months of treatment with an ACE-inhibitor. A system modeling-identification approach was used to estimate the viscoelastic parameters: elastic, viscous and inertial indexes, and to perform an isofrequency analysis (up to 5Hz) of the incremental elastic modulus E inc (jω) of the arterial wall. The new approach, proposed to evaluate the frequency-dependence of arterial wall mechanics, was applied satisfactorily.

A Frequency Domain Model-Order-Deduction Algorithm for Linear Systems

1998 ◽  
Vol 120 (2) ◽  
pp. 185-192 ◽  
Author(s):  
B. H. Wilson ◽  
J. H. Taylor
Keyword(s):  
Frequency Response ◽  
Frequency Domain ◽  
Controller Design ◽  
System Modeling ◽  
Model Performance ◽  
Domain Model ◽  
System Model ◽  
Stopping Criterion ◽  
Model Order ◽  
Primary Means

Physical system modeling, whether automated or manual, requires a systematic procedure to choose the appropriate order of a system model. This can be most readily accomplished by determining the appropriate order of the component submodels. With previous schemes, the primary means to determine the required order of component submodels has been to focus on the eigenvalues of the model, specifically, the behavior of the eigenvalues inside of a circle in the complex plane defining a given spectral radius. In this paper we develop a new algorithm, FD-MODA, that uses changes in a model’s frequency response as an algorithm-stopping-criterion. The model’s frequency response provides a more comprehensive indication of model performance and adequacy than just the eigenvalues, and is more meaningful in the context of frequency-domain controller design methods.

Features of Grounding System Modeling Under Lightning Impact

2021 ◽  
Author(s):  
Yuri E. Adamyan ◽  
Sergey I. Krivosheev ◽  
Ivan S. Kolodkin ◽  
Sergey G. Magazinov ◽  
Julia K. Ochovskaya
Keyword(s):  
System Modeling ◽  
Grounding System

scholarly journals Grounding System Modeling and Evaluation Using Integrated Circuit Based Fast Relaxed Vector Fitting Approach, Considering Soil Ionization

2020 ◽  
Vol 10 (16) ◽  
pp. 5632
Author(s):  
Maziyar Fakhraei ◽  
Mehrdad Mahmoudian ◽  
Eduardo Manuel Godinho Rodrigues
Keyword(s):  
Integrated Circuit ◽  
System Modeling ◽  
Model Verification ◽  
Lightning Strikes ◽  
Grounding System ◽  
Vector Fitting ◽  
Grounding Grids ◽  
Electro Magnetic ◽  
Soil Ionization ◽  
System Frequency

Since high voltage transmission line towers or wind turbines structures are installed in high-altitude areas, it is essential to achieve a high overvoltage protection system against direct and indirect lightning strikes collisions. The lightning current must be discharged quickly into the protective earth, to prevent the dangerous over-voltages formation and define a reference voltage node. This paper presents a novel model to assess the behavior of the grounding system, based on Pocklington integral equations under lightning magnetic fields and variations in soil ionization, in which an explicit circuit-based vector fitting RLC admittance branches are proposed. The frequency-dependent behavior of grounding system frequency response and soil ionization effect is modeled in time domain, straightly to implement into the electro-magnetic transient program (EMTP). The model verification contains horizontal, vertical, and their combinations of grounding grids to represent the complete investigations under lightning strikes. The harmonic impedance mathematical formulations and principles are derived based on a rational function, that could be applicable on ground potential rise (GPR) investigation.

Fault Evolution Characteristic Analysis of Planetary Gear Based on Multidimensional Nonlinear Frequency Response

2019 ◽  
Vol 14 (4) ◽  
Author(s):  
Haitao Wang ◽  
Zhimao Tao ◽  
Lichen Shi ◽  
Zhenya Kang
Keyword(s):  
Fault Diagnosis ◽  
Nonlinear System ◽  
Frequency Response ◽  
Volterra Series ◽  
System Modeling ◽  
Planetary Gear ◽  
Nonlinear Frequency ◽  
Characteristic Analysis ◽  
Loading Test ◽  
Planetary Gearbox

This study presented a method for modeling the nonlinear system of a planetary gearbox and the fault diagnosis of a crack in a planetary gear based on the Volterra series theory. First, the exponential Hilbert reproducing kernel and its fast optimization algorithm was proposed and deduced in theory, and the fast solution of the fourth-order kernel of the Volterra series was successfully solved. Second, the Volterra series model estimation was compared with the least squares estimation of the actual collected signals from the planetary gearbox and the time-domain output signal was estimated using a neural network. The accuracy and the superiority of the Volterra series model of the planetary gearbox were then verified. At the same time, the convergence and the memory length of the Volterra series were discussed. In order to further mine and extract fault feature information, coupling relationship between the generalized frequency response of higher order spectrum of the Volterra series model and fault frequency was also studied. This study attempted to reflect the fault state and fault degree of a crack in a planetary gear from different observation angles and dimensions. Finally, the real condition loading test of a gearbox's comprehensive fault test platform was carried out. The validity of the method of nonlinear system modeling and fault diagnosis of the planetary gearbox, based on the Volterra series theory, was verified, and a new solution has been provided for related research in this field.

Use of Array Capacitors to Improve the Power Delivery Performance of a Microprocessor System

2005 ◽  
Author(s):  
Kimberly D. Eilert ◽  
Kaladhar Radhakrishnan ◽  
Michael J. Hill ◽  
Kemal Aygu¨n
Keyword(s):  
Frequency Response ◽  
System Modeling ◽  
Simulation Models ◽  
Power Delivery ◽  
Microprocessor System ◽  
High Frequency Response ◽  
Measurement Results ◽  
Impedance Profile ◽  
System Frequency ◽  
The Impact

We show system modeling and measurement results of a platform with array capacitor solution (ACS) within the frequency domain. A Pentium® 4 microprocessor package was redesigned for a single array capacitor, in place of all multiterminal capacitors. Its system power delivery impedance profile was found to have a more desirable high frequency response than the earlier system designed with discrete multiterminal capacitors. These measured results were also found to agree well with the behavior predicted by simulation models. Additionally we explore the impact and optimization of array capacitor parameters on the overall system frequency response.

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