Modeling and analysis of dielectric materials by using gradient-descent optimization method

2017 ◽  
Vol 08 (01) ◽  
pp. 1750014
Author(s):  
B. B. Alagoz ◽  
H. Z. Alisoy ◽  
M. Koseoglu ◽  
S. Alagoz
Keyword(s):  
Equivalent Circuit ◽  
Gradient Descent ◽  
Model Fitting ◽  
Equivalent Circuit Model ◽  
Optimization Method ◽  
Dielectric Materials ◽  
Circuit Model ◽  
Modeling And Analysis ◽  
Modeling Analysis ◽  
Equivalent Circuit Parameters

This study presents a numerical method based on parallel RC equivalent circuit model fitting methodology for analysis and modeling of dielectric materials. The proposed method employs gradient-descent optimization method (GDOM) to estimate parallel RC equivalent circuit model from current waveforms by minimizing sum of squared difference (SSD) error. Estimation of parallel RC equivalent circuit parameters from measured current waveforms provides a useful tool for identification, simulation and analysis of dielectric materials. Moreover, applications of the proposed method for time and frequency analyses of dielectric materials are demonstrated numerically. Numerical simulations were presented to discuss efficiency of the proposed method for modeling, analysis and monitoring of insulator materials.

Simple Prediction of Tunable Metamaterial Absorbers Reflectivity Characteristics Using Equivalent Circuit Model

2014 ◽  
Vol 875-877 ◽  
pp. 957-961 ◽  
Author(s):  
Cai Fang Zhang ◽  
Gen Qiang Jing ◽  
Xin Xin Xu
Keyword(s):  
Equivalent Circuit ◽  
Equivalent Circuit Model ◽  
Dielectric Substrate ◽  
Circuit Model ◽  
New Combination ◽  
Modeling Analysis ◽  
Working Principle ◽  
Metamaterial Absorbers ◽  
Tunable Metamaterial ◽  
Good Agreement

A modeling analysis and verification of tunable metamaterial absorbers (MA) comprised of a new combination shaped metal elements printed on a dielectric substrate loaded with PIN diodes were presented. Unlike conventional transmission line analysis, new modeling analysis allows arbitrarily shaped elements to be calculated. A qualitative analysis by a simple equivalent circuit model is carried out on the parameters of the tunable MA. Thus, samples of the tunable MA are fabricated. The measured results are in good agreement with the predicted ones. The study shows that the modeling analysis is simple and practicable to describe the working principle of the tunable MA structure.

scholarly journals Parameter Extraction for Equivalent Circuit Model of RF Devices Based on a Hybrid Optimization Method

Electronics ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 1133 ◽  
Author(s):  
Zhimin Guan ◽  
Peng Zhao ◽  
Qizhong Lao ◽  
Xianbing Wang ◽  
Gaofeng Wang
Keyword(s):  
Equivalent Circuit ◽  
Global Minimum ◽  
Extraction Procedure ◽  
Equivalent Circuit Model ◽  
Optimization Method ◽  
Parameter Extraction ◽  
Circuit Model ◽  
Spiral Inductor ◽  
Rf Devices ◽  
Global Minimum Search

One major difficulty of parameter extraction for an equivalent circuit lies in applying an optimization algorithm to efficiently approach the global minimum. Traditional genetic algorithm (GA) is able to find the global minimum but it has very low convergence rate. On the other hand, direct search method may be easily trapped in local minima. In this work, an improved parameter extraction method which is capable of effectively performing the global minimum search is proposed. This method combines GA and Powell’s method to efficiently determine circuit elements of an equivalent circuit model. A spiral inductor and an interdigital capacitor are used as design examples to illustrate the extraction procedure and validate the proposed hybrid method.

scholarly journals Investigation of the effects of the equivalent circuit parameters on induction motor torque using three different equivalent circuit models

2018 ◽  
Vol 157 ◽  
pp. 01019
Author(s):  
Mehmet Murat Tezcan ◽  
Asim Gökhan Yetgin ◽  
Ali Ihsan Canakoglu ◽  
Bariş Cevher ◽  
Mustafa Turan ◽  
...  
Keyword(s):  
Equivalent Circuit ◽  
Induction Motor ◽  
Characteristic Curve ◽  
Equivalent Circuit Model ◽  
Circuit Model ◽  
Rotor Resistance ◽  
Equivalent Circuit Parameters ◽  
Torque Values ◽  
Cage Induction Motor ◽  
Equivalent Circuit Models

In this study, the most vital characteristic properties of induction motor, motor starting, maximum and nominal torque are analyzed for what are affected. For the analysis of torque, L type, T type and IEEE 112 equivalent circuit model is employed. Torque change is investigated with the help of codes developed in MATLAB to be used in electrical machines course. First, the slip-moment characteristic curve of the induction motor is divided into three working zones and it was determined which equivalent circuit model gave the best results in these study zones. Later, such parameters as stator and rotor resistance, stator and rotor reactance, magnetization reactance, core resistance and slip are researched for how torque values are affected from. The obtained values for each of the three equivalent circuit models are given and compared with experimental results. 50 HP squirrel cage induction motor parameters are used in analysis. In the analysis, the most influential parameters on the starting torque are found as rotor resistance and stator and rotor reactance. Change of other parameters’ impact ratio depending upon right proportion and inverse proportion is observed. When nominal torque variations are investigated, again rotor resistance is the most influential parameter and by selecting proper factor effecting rotor resistance during design, the result of acquiring desired rotor resistance is obtained. When the maximum torque variations are examined, it appears that the stator and rotor reactance values are effective. Starting, maximum and nominal torque expressions change with square of voltage alters the effect on them a lot. Therefore, triangle or star connection importance arises during machine design.

An Equivalent Circuit Model for Vertical Comb Drive MEMS Optical Scanner Controlled by Pulse Width Modulation

2012 ◽  
Vol 132 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Satoshi Maruyama ◽  
Muneki Nakada ◽  
Makoto Mita ◽  
Takuya Takahashi ◽  
Hiroyuki Fujita ◽  
...  
Keyword(s):  
Equivalent Circuit ◽  
Pulse Width ◽  
Pulse Width Modulation ◽  
Equivalent Circuit Model ◽  
Circuit Model ◽  
Comb Drive ◽  
Optical Scanner

scholarly journals A Novel, Improved Equivalent Circuit Model for Double-Sided Linear Induction Motor

Electronics ◽  
2021 ◽  
Vol 10 (14) ◽  
pp. 1644
Author(s):  
Qian Zhang ◽  
Huijuan Liu ◽  
Tengfei Song ◽  
Zhenyang Zhang
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Equivalent Circuit ◽  
Skin Effect ◽  
Equivalent Circuit Model ◽  
Element Model ◽  
Circuit Model ◽  
End Effects ◽  
3D Finite Element ◽  
Linear Induction

A novel, improved equivalent circuit model of double-sided linear induction motors (DLIMs) is proposed, which takes the skin effect and the nonzero leakage reactance of the secondary, longitudinal, and transverse end effects into consideration. Firstly, the traditional equivalent circuit with longitudinal and transverse end effects are briefly reviewed. Additionally, the correction coefficients for longitudinal and transverse end effects derived by one-dimensional analysis models are given. Secondly, correction factors for skin effect, which reflects the inhomogeneous air gap magnetic field vertically, and the secondary leakage reactance are derived by the quasi-two-dimensional analysis model. Then, the proposed equivalent circuit is presented, and the excitation reactance and secondary resistance are modified by the correction coefficients derived from the three analytical models. Finally, a three-dimensional (3D) finite element model is used to verify the proposed equivalent circuit model under varying air gap width and frequency, and the results are also compared with that of the traditional equivalent circuit models. The calculated thrust characteristics by the proposed equivalent circuit and 3D finite element model are experimentally validated under a constant voltage–frequency drive.

Mesh Dependency on a Partial Element Equivalent Circuit Model for an NI HTS Coil

2021 ◽  
Vol 31 (5) ◽  
pp. 1-5
Author(s):  
Chaemin Im ◽  
Geonyoung Kim ◽  
Jeseok Bang ◽  
Kibum Choi ◽  
Soobin An ◽  
...  
Keyword(s):  
Equivalent Circuit ◽  
Equivalent Circuit Model ◽  
Circuit Model ◽  
Mesh Dependency ◽  
Partial Element Equivalent Circuit ◽  
Partial Element
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