Combined lumped element network and transmission line synthesis for passive microwave structures

Abstract. Compact circuit models of electromagnetic structures are a valuable tool for embedding distributed circuits into complex circuits and systems. However, electromagnetic structures with large internal propagation delay are described by impedance functions with a large number of frequency poles in a given frequency interval and therefore yielding equivalent circuit models with a high number of lumped circuit elements. The number of circuit elements can be reduced considerably if in addition to capacitors, inductors, resistors and ideal transformers also delay lines are included. In this contribution a systematic procedure for the generation of combined lumped element/delay line equivalent circuit models on the basis of numerical data is described. The numerical data are obtained by numerical full-wave modeling of the electromagnetic structure. The simulation results are decomposed into two parts representing a lumped elements model and a delay line model. The extraction of the model parameters is performed by application of the system identification procedure to the scattering transfer function. Examples for the modeling of electromagnetic structures are presented.

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Estimation of the model parameters in equivalent circuit models of potential transformers

IEEE Power Engineering Society. 1999 Winter Meeting (Cat. No.99CH36233) ◽

10.1109/pesw.1999.747347 ◽

1999 ◽

Cited By ~ 6

Author(s):

B. Bak-Jensen ◽

L. Ostergaard

Keyword(s):

Equivalent Circuit ◽

Model Parameters ◽

Equivalent Circuit Models

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Lumped-element equivalent circuit models for multilayer ring resonators filters

2011 IEEE International Conference on Ultra-Wideband (ICUWB) ◽

10.1109/icuwb.2011.6058898 ◽

2011 ◽

Cited By ~ 4

Author(s):

Seyyed Kamal Hashemi

Keyword(s):

Equivalent Circuit ◽

Ring Resonators ◽

Lumped Element ◽

Equivalent Circuit Models

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Extraction of lumped-element equivalent-circuit models of microstrip discontinuities using the finite-difference time-domain method

Microwave and Optical Technology Letters ◽

10.1002/mop.10254 ◽

2002 ◽

Vol 33 (2) ◽

pp. 132-134 ◽

Cited By ~ 3

Author(s):

Nader Farahat ◽

Wenhua Yu ◽

Raj Mittra

Keyword(s):

Finite Difference ◽

Equivalent Circuit ◽

Time Domain ◽

Finite Difference Time Domain ◽

Time Domain Method ◽

Lumped Element ◽

Domain Method ◽

Difference Time ◽

Microstrip Discontinuities ◽

Equivalent Circuit Models

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A Comparative Study of Two Fractional-Order Equivalent Electrical Circuits for Modeling the Electrical Impedance of Dental Tissues

Entropy ◽

10.3390/e22101117 ◽

2020 ◽

Vol 22 (10) ◽

pp. 1117 ◽

Cited By ~ 1

Author(s):

Norbert Herencsar ◽

Todd J. Freeborn ◽

Aslihan Kartci ◽

Oguzhan Cicekoglu

Keyword(s):

Equivalent Circuit ◽

Fractional Order ◽

Biological Tissue ◽

Electrical Impedance ◽

Model Parameters ◽

Dental Tissue ◽

Tissue Impedance ◽

Dental Tissues ◽

Impedance Models ◽

Equivalent Circuit Models

Background: Electrical impedance spectroscopy (EIS) is a fast, non-invasive, and safe approach for electrical impedance measurement of biomedical tissues. Applied to dental research, EIS has been used to detect tooth cracks and caries with higher accuracy than visual or radiographic methods. Recent studies have reported age-related differences in human dental tissue impedance and utilized fractional-order equivalent circuit model parameters to represent these measurements. Objective: We aimed to highlight that fractional-order equivalent circuit models with different topologies (but same number of components) can equally well model the electrical impedance of dental tissues. Additionally, this work presents an equivalent circuit network that can be realized using Electronic Industries Alliance (EIA) standard compliant RC component values to emulate the electrical impedance characteristics of dental tissues. Results: To validate the results, the goodness of fits of electrical impedance models were evaluated visually and statistically in terms of relative error, mean absolute error (MAE), root mean squared error (RMSE), coefficient of determination (R2), Nash–Sutcliffe’s efficiency (NSE), Willmott’s index of agreement (WIA), or Legates’s coefficient of efficiency (LCE). The fit accuracy of proposed recurrent electrical impedance models for data representative of different age groups teeth dentin supports that both models can represent the same impedance data near perfectly. Significance: With the continued exploration of fractional-order equivalent circuit models to represent biological tissue data, it is important to investigate which models and model parameters are most closely associated with clinically relevant markers and physiological structures of the tissues/materials being measured and not just “fit” with experimental data. This exploration highlights that two different fractional-order models can fit experimental dental tissue data equally well, which should be considered during studies aimed at investigating different topologies to represent biological tissue impedance and their interpretation.

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Thermal Analysis of LMO/Graphite Batteries Using Equivalent Circuit Models

Batteries ◽

10.3390/batteries7030058 ◽

2021 ◽

Vol 7 (3) ◽

pp. 58

Author(s):

Nadjiba Mahfoudi ◽

M’hamed Boutaous ◽

Shihe Xin ◽

Serge Buathier

Keyword(s):

Thermal Behavior ◽

Equivalent Circuit ◽

Thermal Management ◽

Dynamic Models ◽

Operating Time ◽

Operating Conditions ◽

State Of Charge ◽

Model Parameters ◽

Battery Model ◽

Equivalent Circuit Models

An efficient thermal management system (TMS) of electric vehicles requires a high-fidelity battery model. The model should be able to predict the electro-thermal behavior of the battery, considering the operating conditions throughout the battery’s lifespan. In addition, the model should be easy to handle for the online monitoring and control of the TMS. Equivalent circuit models (ECMs) are widely used because of their simplicity and suitable performance. In this paper, the electro-thermal behavior of a prismatic 50 Ah LMO/Graphite cell is investigated. A dynamic model is adopted to describe the battery voltage, current, and heat generation. The battery model parameters are identified for a single cell, considering their evolution versus the state of charge and temperature. The needed experimental data are issued from the measurements carried out, thanks to a special custom electrical bench able to impose a predefined current evolution or driving cycles, controllable by serial interface. The proposed battery parameters, functions of state of charge (SOC), and temperature (T) constitute a set of interesting and complete data, not available in the literature, and suitable for further investigations. The thermal behavior and the dynamic models are validated using the New European Driving Cycle (NEDC), with a large operating time, higher than 3 h. The measurement and model prediction exhibit a temperature difference less than 1.2 °C and a voltage deviation less than 3%, showing that the proposed model accurately predicts current, voltage, and temperature. The combined effects of temperature and SOC provides a more efficient modeling of the cell behavior. Nevertheless, the simplified model with only temperature dependency remains acceptable. Hence, the present modeling constitutes a confident prediction and a real step for an online control of the complete thermal management of electrical vehicles.

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