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Article
Publication date: 1 June 2000

K. Wiak

Discusses the 27 papers in ISEF 1999 Proceedings on the subject of electromagnetisms. States the groups of papers cover such subjects within the discipline as: induction…

Abstract

Discusses the 27 papers in ISEF 1999 Proceedings on the subject of electromagnetisms. States the groups of papers cover such subjects within the discipline as: induction machines; reluctance motors; PM motors; transformers and reactors; and special problems and applications. Debates all of these in great detail and itemizes each with greater in‐depth discussion of the various technical applications and areas. Concludes that the recommendations made should be adhered to.

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COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 19 no. 2
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 1 June 2000

A. Savini

Gives introductory remarks about chapter 1 of this group of 31 papers, from ISEF 1999 Proceedings, in the methodologies for field analysis, in the electromagnetic…

Abstract

Gives introductory remarks about chapter 1 of this group of 31 papers, from ISEF 1999 Proceedings, in the methodologies for field analysis, in the electromagnetic community. Observes that computer package implementation theory contributes to clarification. Discusses the areas covered by some of the papers ‐ such as artificial intelligence using fuzzy logic. Includes applications such as permanent magnets and looks at eddy current problems. States the finite element method is currently the most popular method used for field computation. Closes by pointing out the amalgam of topics.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 19 no. 2
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 10 April 2007

G.B. Kumbhar, S.V. Kulkarni, R. Escarela‐Perez and E. Campero‐Littlewood

This paper aims to give a perspective about the variety of techniques which are available and are being further developed in the area of coupled field formulations, with…

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Abstract

Purpose

This paper aims to give a perspective about the variety of techniques which are available and are being further developed in the area of coupled field formulations, with selective bibliography and practical examples, to help postgraduate students, researchers and designers working in design or analysis of electrical machinery.

Design/methodology/approach

This paper reviews the recent trends in coupled field formulations. The use of these formulations for designing and non‐destructive testing of electrical machinery is described, followed by their classifications, solutions and applications. Their advantages and shortcomings are discussed.

Findings

The paper gives an overview of research, development and applications of coupled field formulations for electrical machinery based on more than 160 references. All landmark papers are classified. Practical engineering case studies are given which illustrate wide applicability of coupled field formulations.

Research limitations/implications

Problems which continue to pose challenges to researchers are enumerated and the advantages of using the coupled‐field formulation are pointed out.

Practical implications

This paper gives a detailed description of the application of the coupled field formulation method to the analysis of problems that are present in different electrical machines. Examples of analysis of generators and transformers with this formulation are presented. The application examples give guidelines for its use in other analyses.

Originality/value

The coupled‐field formulation is used in the analysis of rotational machines and transformers where reference data are available and comparisons with other methods are performed and the advantages are justified. This paper serves as a guide for the ongoing research on coupled problems in electrical machinery.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 26 no. 2
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 5 May 2015

Mykhaylo Zagirnyak, Mariia Maliakova and Andrii Kalinov

Analytical determination of harmonic components of current in electric circuits containing semiconductor converters with the use of a small parameter method (SPM) in…

Abstract

Purpose

Analytical determination of harmonic components of current in electric circuits containing semiconductor converters with the use of a small parameter method (SPM) in frequency domain. The paper aims to discuss these issues.

Design/methodology/approach

A SPM realized in frequency domain was used in the analytical analysis of electric circuits with semiconductor converters. An automated method of formation of orthogonal harmonic components of electrical values on the basis of discrete convolution algorithm was used to provide the possibility of realization of calculation in frequency domain. A nonlinear characteristic of a semiconductor converter was presented by the method of numerical approximation. A numerical structured simulation method was applied to determination of the reference values of current in the analyzed circuit. Laws of theoretical electrical engineering were used for formation of the equations of voltage balance in the circuit with a nonlinear element.

Findings

It is shown that application of a SPM with its realization in frequency domain enables significant simplification of the process of the analysis of electric circuits with semiconductor converters in an analytical form and facilitation of calculation automation. Analytical and numerical calculation of a circuit with a diode under active-inductive load demonstrated efficiency and sufficient accuracy of the proposed method. It is shown that increase of the order of approximating polynomial and of the number of the analyzed harmonics provides the improvement of the accuracy of numerical calculations.

Practical implications

The results of the work can be used in calculation of electrotechnical devices containing semiconductor appliances and electric devices with nonlinear characteristics. Moreover, the obtained results enable studying the processes of compensation of current higher harmonics in electric networks with a nonlinear load containing semiconductor converters.

Originality/value

For the first time it was proposed to apply a SPM with its realization in frequency domain to the analysis of nonlinear electric circuits. The significance of the paper consists in the fact that the offered method makes it possible to carry out both circuit analytical and numerical analysis with the possibility of its automation.

Details

COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering, vol. 34 no. 3
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 17 March 2021

André Oksas

This paper aims to show how a sociological description – a swarm analysis of the Nazi dictatorship – initially made with the means borrowed from George Spencer-Brown’s…

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Abstract

Purpose

This paper aims to show how a sociological description – a swarm analysis of the Nazi dictatorship – initially made with the means borrowed from George Spencer-Brown’s Calculus of Indications, can be transformed into a digital circuit and with which methods and tools of digital mathematics this digital circuit can be analyzed and described in its behavior. Thus, the paper also aims to contribute to a better understanding of Chapter 11 of “Laws of Form.”

Design/methodology/approach

The analysis uses methods of automata theory for finite, deterministic automata. Basic set operations of digital mathematics and special set operations of the Boolean Differential Calculus are used to calculate digital circuits. The software used is based on ternary logic, in which the binary Boolean logic of the elements {0, 1} is extended by the third element “Don’t care” to {0, 1, −}.

Findings

The paper confirms the method of transforming a form into a digital circuit derived from the comparative functional and structural analysis of the Modulator from Chapter 11 of “Laws of Form” and defines general rules for this transformation. It is shown how the indeterminacy of re-entrant forms can be resolved in the medium of time using the methods of automata theory. On this basis, a refined definition of the degree of a form is presented.

Originality/value

The paper shows the potential of interdisciplinary approaches between sociology and information technology and provides methods and tools of digital mathematics such as ternary logic, Boolean Differential Calculus and automata theory for application in sociology.

Details

Kybernetes, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0368-492X

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Article
Publication date: 14 July 2021

Taochen Gu, Fayu Wan, Jamel Nebhen, Nour Mohammad Murad, Jérôme Rossignol, Sebastien Lallechere and Blaise Ravelo

The aim of this paper is to provide the theoretical conceptualization of a bandpass (BP) negative group delay (NGD) microstrip circuit. The main objective is to provide a…

Abstract

Purpose

The aim of this paper is to provide the theoretical conceptualization of a bandpass (BP) negative group delay (NGD) microstrip circuit. The main objective is to provide a theorization of the particular geometry of the microstrip circuit with experimental validation of the NGD effect.

Design/methodology/approach

The methodology followed in this work is organized in three steps. A theoretical model is established of equivalent S-parameters model using Y-matrix analysis. The GD analysis is also presented by showing that the circuit presents a possibility to generate NGD function around certain frequencies. To validate the theoretical model, as proof-of-concept (POC), a microstrip prototype is designed, fabricated and tested.

Findings

This work clearly highlighted the modelled (analytical design model), simulated (ADS simulation tool) and measured results are in good correlation. Relying on the proposed theoretical, numerical and experimental models, the BP NGD behaviour is validated successfully with GD responses specified by the NGD centre frequency: it is observed around 2.35 GHz, with an NGD value of about −2 ns.

Research limitations/implications

It is to be noticed the proposed GD analysis requires limitations of the theoretical NGD model. It is depicted and validated through a POC demonstrating that the circuit presents a possibility to generate NGD function around certain frequencies (assuming constraints around usable frequency and bandwidth).

Practical implications

The NGD O-shape topology developed in this work could be exploited in the future in the microwave and radiofrequency context. Thus, it is expected to develop GD equalization technique for radiofrequency and microwave filters, GD compensation of oscillators, filters and communication systems, design of broadband switch-less bi-directional amplifiers, efficient enhancement of feedforward amplifiers, design method of frequency independent phase shifters with negligible delay, synthesis method of arbitrary-angle beamforming antennas. The BP NGD behavior may also be successfully used for the reduction of resonance effect for the electronic compatibility (EMC) of electronic devices.

Social implications

The non-conventional NGD O-circuit theoretical development and validation through experimental POC could be exploited by academic and industrial developers in the area of wireless communications including, but not restricted to, 5-generation communication systems. The use of the remarkable NGD effect is also useful for the mitigation of electromagnetic interferences between electronic devices and more and more complex electromagnetic environment (current development of Internet of Things[ IoT]).

Originality/value

The originality of this work relies on the new NGD design proposed in this work including the extraction of S-matrix parameters of the microstrip novel structure designed. The validation process based upon an experimental POC showed very interesting levels of NGD O-circuit (nanosecond-GD duration).

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering , vol. 40 no. 3
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 28 October 2014

Alexander Zemliak

The purpose of this paper is to define the process of analog circuit optimization on the basis of the control theory application. This approach produces many different…

Abstract

Purpose

The purpose of this paper is to define the process of analog circuit optimization on the basis of the control theory application. This approach produces many different strategies of optimization and determines the problem of searching of the best strategy in sense of minimal computer time. The determining of the best strategy of optimization and a searching of possible structure of this strategy with a minimal computer time is a principal aim of this work.

Design/methodology/approach

Different kinds of strategies for circuit optimization have been evaluated from the point of view of operations’ number. The generalized methodology for the optimization of analog circuit was formulated by means of the optimum control theory. The main equations for this methodology were elaborated. These equations include the special control functions that are introduced artificially. This approach generalizes the problem and generates an infinite number of different strategies of optimization. A problem of construction of the best algorithm of optimization is defined as a typical problem of the control theory. Numerical results show the possibility of application of this approach for optimization of electronic circuits and demonstrate the efficiency and perspective of the proposed methodology.

Findings

Examples show that the better optimization strategies that are appeared in limits of developed approach have a significant time gain with respect to the traditional strategy. The time gain increases when the size and the complexity of the optimized circuit are increasing. An additional acceleration effect was used to improve the properties of presented optimization process.

Originality/value

The obtained results show the perspectives of new approach for circuit optimization. A large set of various strategies of circuit optimization serves as a basis for searching the better strategies with a minimum computer time. The gain in processor time for the best strategy reaches till several thousands in comparison with traditional approach.

Details

COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering, vol. 33 no. 6
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 1 April 1991

Michael Schröter

A program for numerical simulation of two‐dimensional semiconductor devices coupled with an external circuit is described. The circuit equations are formulated using…

Abstract

A program for numerical simulation of two‐dimensional semiconductor devices coupled with an external circuit is described. The circuit equations are formulated using modified nodal analysis to allow an arbitrary configuration of elements like, e.g., also semiconductor compact models. Coupling to the numerical devices is attained via their admittance matrix leading to a two‐level Newton method. To calculate this matrix two methods are compared: (a) a linearization scheme and (b) a secant method. The comparison shows a significant speed advantage of the secant method despite its lower rate of convergence. The linearization scheme, however, is the more stable and robust method and should be used in critical cases where convergence problems can occur. An efficient bypassing scheme was developed for the linearization scheme leading to a computation speed comparable to that of the secant method, but maintaining the better convergence properties. A further advantage of the two‐level Newton method used in this work is that the CPU‐time consuming solution for the numerical devices can be done in parallel on different processors. Several examples are given to demonstrate the capabilities of the developed simulator.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 10 no. 4
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 24 November 2021

Rawid Banchuin

The purpose of this paper is to present the analyses of electrical circuits with arbitrary source terms defined on middle b cantor set by means of nonlocal fractal…

Abstract

Purpose

The purpose of this paper is to present the analyses of electrical circuits with arbitrary source terms defined on middle b cantor set by means of nonlocal fractal calculus and to evaluate the appropriateness of such unconventional calculus.

Design/methodology/approach

The nonlocal fractal integro-differential equations describing RL, RC, LC and RLC circuits with arbitrary source terms defined on middle b cantor set have been formulated and solved by means of fractal Laplace transformation. Numerical simulations based on the derived solutions have been performed where an LC circuit has been studied by means of Lagrangian and Hamiltonian formalisms. The nonlocal fractal calculus-based Lagrangian and Hamiltonian equations have been derived and the local fractal calculus-based ones have been revisited.

Findings

The author has found that the LC circuit defined on a middle b cantor set become a physically unsound system due to the unreasonable associated Hamiltonian unless the local fractal calculus has been applied instead.

Originality/value

For the first time, the nonlocal fractal calculus-based analyses of electrical circuits with arbitrary source terms have been performed where those circuits with order higher than 1 have also been analyzed. For the first time, the nonlocal fractal calculus-based Lagrangian and Hamiltonian equations have been proposed. The revised contradiction free local fractal calculus-based Lagrangian and Hamiltonian equations have been presented. A comparison of local and nonlocal fractal calculus in terms of Lagrangian and Hamiltonian formalisms have been made where a drawback of the nonlocal one has been pointed out.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering , vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 2 May 2017

Vadimas Verdingovas, Salil Joshy, Morten Stendahl Jellesen and Rajan Ambat

The purpose of this study is to show that the humidity levels for surface insulation resistance (SIR)-related failures are dependent on the type of activators used in…

Abstract

Purpose

The purpose of this study is to show that the humidity levels for surface insulation resistance (SIR)-related failures are dependent on the type of activators used in no-clean flux systems and to demonstrate the possibility of simulating the effects of humidity and contamination on printed circuit board components and sensitive parts if typical SIR data connected to a particular climatic condition are available. This is shown on representative components and typical circuits.

Design/methodology/approach

A range of SIR values obtained on SIR patterns with 1,476 squares was used as input data for the circuit analysis. The SIR data were compared to the surface resistance values observable on a real device printed circuit board assembly. SIR issues at the component and circuit levels were analysed on the basis of parasitic circuit effects owing to the formation of a water layer as an electrical conduction medium.

Findings

This paper provides a summary of the effects of contamination with various weak organic acids representing the active components in no-clean solder flux residue, and demonstrates the effect of humidity and contamination on the possible malfunctions and errors in electronic circuits. The effect of contamination and humidity is expressed as drift from the nominal resistance values of the resistors, self-discharge of the capacitors and the errors in the circuits due to parasitic leakage currents (reduction of SIR).

Practical/implications

The methodology of the analysis of the circuits using a range of empirical leakage resistance values combined with the knowledge of the humidity and contamination profile of the electronics can be used for the robust design of a device, which is also important for electronic products relying on low current consumption for long battery lifetime.

Originality/value

Examples provide a basic link between the combined effect of humidity and contamination and the performance of electronic circuits. The methodology shown provides the possibility of addressing the climatic reliability of an electronic device at the early stage of device design by using typical SIR data representing the possible climate exposure.

Details

Circuit World, vol. 43 no. 2
Type: Research Article
ISSN: 0305-6120

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