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Article
Publication date: 4 September 2018

Lukasz Knypinski, Krzysztof Kowalski and Lech Nowak

The purpose of this paper is to elaborate algorithm and software for the optimization of the actuator–capacitor system taking the dynamics parameters into account. The…

Abstract

Purpose

The purpose of this paper is to elaborate algorithm and software for the optimization of the actuator–capacitor system taking the dynamics parameters into account. The system is applied for driving the valve of plasma gun. Two optimization strategies are proposed and pondered. The penalty function approach has been expanded in detail.

Design/methodology/approach

The field-circuit mathematical model of the dynamics operation consists of the strongly coupled equations of the transient electromagnetic fields and the equations of the electric circuit. The numerical implementation is based on finite element method and step-by-step Cranck–Nicholson procedure. The genetic algorithm has been used in the optimization procedure. The sigmoidal transformation has been applied to adjust the classical external penalty function method to the genetic algorithm.

Findings

The modification consists in adaptation of the penalty function to the genetic algorithm. In the proposed approach, operations involving successive iterations of increasing penalty function and operations containing genetic iterations are intertwined with each other. The differences between these two procedures are getting blurred. The proposed approach is very effective. It is possible to achieve optimal solution even more than ten times faster than using the classical method.

Originality/value

The proposed approach can be successfully applied to designing and optimization of different electromagnetic devices, including functional constraints.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 37 no. 5
Type: Research Article
ISSN: 0332-1649

Keywords

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Article
Publication date: 1 January 2006

Jacek Mikołajewicz and Lech Nowak

The aim of the paper is to find the effective methods of power loss reduction in axisymmetric electromagnetic devices and improve their dynamic parameters. As an example…

Abstract

Purpose

The aim of the paper is to find the effective methods of power loss reduction in axisymmetric electromagnetic devices and improve their dynamic parameters. As an example the linear tubular motor is considered.

Design/methodology/approach

The elaborated algorithm has been applied to analyze the dynamic operation of axisymmetric electromagnetic devices, especially tubular linear induction motors. The mathematical model of transients includes: the equation of electromagnetic field, the equations of electric circuits and the equation of motion. The model is based on the finite element method. For the time‐stepping, the Cranck‐Nicholson scheme is applied. In order to include non‐linearity, the Newton‐Raphson process is adopted.

Findings

In order to reduce the influence of eddy currents, it is suggested that the solid core should be equipped with one or several radial slots. In such a case, the radial component of eddy currents occurs near the slot and disturbs the axial symmetry of the system. However, when the width of the slot is small, the fields generated by the radial component of eddy currents on both sides of the slot practically cancel one another and the system can still be considered axisymmetric. Another solution given in the paper consists of replacing the cylindrical core with a system of flat laminated segments. In such a case, saturation of the ferromagnetic parts is greater than in the case of classical axisymmetric core.

Originality/value

In the paper, new quasi‐2D axisymmetrical field‐circuit methodology for electromagnetic device dynamics analysis has been elaborated. Proposed constructional solutions enable one to reduce the power losses in the primary core by half and total losses by 30 percent.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 25 no. 1
Type: Research Article
ISSN: 0332-1649

Keywords

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Article
Publication date: 14 August 2007

Jerzy Kołowrotkiewicz, Mariusz Barański, Wojciech Szelęg and Lech Długiewicz

The paper aims to elaborate the method and algorithm of analysis of induction motor working in cryogenic temperature.

Abstract

Purpose

The paper aims to elaborate the method and algorithm of analysis of induction motor working in cryogenic temperature.

Design/methodology/approach

This paper presents the design and investigation of performance characteristics of three‐phase high voltage squirrel‐cage submerged motor. The motor is intended to work at cryogenic temperature −161°C in liquefied natural gas (LNG). The time‐stepping finite element method of transients analysis in induction motor working in cryogenic temperature has been presented. The nonlinearity of the magnetic circuit, the movement of the rotor and skewed slots have been taken into account.

Findings

The study finds that presented method and elaborated software are used to determine the steady state and dynamic performance of the high voltage squirrel‐cage submerged motor. The results of simulations and measurements of constructed model motor have been presented.

Research limitations/implications

The problem has been considered as the 2D one. In order to take into account the skewed slots of the rotor the multi‐slice finite element method has been used.

Practical implications

Investigation presented in the paper has been performed in order to study the influence of the temperature on motor characteristics and to verify design calculations. No‐load current, starting torque and short‐circuit current during short‐circuit test, obtained on the basis of measurements and received from calculations, are in good concordance.

Originality/value

The paper proposes a method to determine the steady state and dynamic performance of the high voltage squirrel‐cage submerged motor working in cryogenic temperature.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 26 no. 4
Type: Research Article
ISSN: 0332-1649

Keywords

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Article
Publication date: 10 May 2011

Łukasz Knypiński and Lech Nowak

The purpose of this paper is to elaborate a mathematical model of dynamic operation of the permanent magnet brushless DC (BLDC) motor with outer rotor and investigate the…

Abstract

Purpose

The purpose of this paper is to elaborate a mathematical model of dynamic operation of the permanent magnet brushless DC (BLDC) motor with outer rotor and investigate the influence of magnets width on the dynamic parameters.

Design/methodology/approach

The mathematical model of the devices includes: the equation of the electromagnetic field, the electric circuit equations and equation of mechanical motion. In elaborated algorithm, all these equations are coupled – therefore they are solved simultaneously. The numerical implementation is based on finite element method and step‐by‐step algorithm. The non‐linear‐coupled field‐circuit equations have been solved by using the Newton‐Raphson algorithm. The computer code for dynamics simulation of the machine has been developed.

Findings

The elaborated algorithm and the computer code have been applied for the 2D simulation of BLDC motor dynamics. The algorithm has a good convergence and its usefulness was proved. Various results of the analysis are presented and discussed.

Originality/value

The presented approach and computer code can be successfully applied to the design and optimization of different structure of the BLDC motors.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 30 no. 3
Type: Research Article
ISSN: 0332-1649

Keywords

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Article
Publication date: 14 August 2007

Lech Nowak and Kazimierz Radziuk

The paper seeks to present an algorithm for a dynamical field‐circuit coupled simulation of an electromagnetic linear actuator operating in automated control systems.

Abstract

Purpose

The paper seeks to present an algorithm for a dynamical field‐circuit coupled simulation of an electromagnetic linear actuator operating in automated control systems.

Design/methodology/approach

The mathematical model includes: a transient electromagnetic field formulation for a non‐linear conducting and moving medium, equations which describe the electric circuits of the converter and the supply system, the equation of mechanical motion, the equation describing closed‐loop control and models for the sensor and the PID controller. The numerical implementation is based on the finite element method and the step‐by‐step algorithm for time discretization. In order to account for the nonlinearity of the ferromagnetic core the Newton‐Raphson procedure has been applied. The influence of the PID controller settings on the operation of the controlled actuator is shown. Dynamic disturbances, e.g. step change of the set value of mover position or change of loading force, have been analyzed.

Findings

The elaborated algorithm and the computer code can be an effective tool for field‐circuit simulation of the dynamics of an electromagnetic linear actuator operating in an automatic control system. Only tapered plunger should be used as multi‐stable actuators.

Originality/value

The study provides information of value in electromagnetic research.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 26 no. 4
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 1 April 1995

Wojciech Szelag, Andrzej Demenko and Lech Nowak

The time‐stepping finite method of transient analysis in permanent magnet synchronous machines has been presented. This method has been used for determining the…

Abstract

The time‐stepping finite method of transient analysis in permanent magnet synchronous machines has been presented. This method has been used for determining the steady‐state and dynamic performance of the permanent magnet self‐starting synchronous motor. The movement of the rotor, the saturation of the ferromagnetic core, the properties of permanent magnet and eddy currents in the solid bars of the cage winding have been taken into account.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 14 no. 4
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 1 March 2001

Lech Nowak

An algorithm for the simultaneous solving of the equations of the 3D transient electromagnetic field and equations of electric circuits of an electromagnetic device…

Abstract

An algorithm for the simultaneous solving of the equations of the 3D transient electromagnetic field and equations of electric circuits of an electromagnetic device containing moving conducting parts has been elaborated. The A‐T formulation has been applied to the description of 3D eddy current problem. In order to solve the 3D problem, the iterative procedure, in which the 3D task is substituted with a sequence of 2D problems, has been applied. Different procedures for movement modelling have been considered. As an example, the dynamics of a linear induction motor have been investigated.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 20 no. 1
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 5 January 2010

Lech Nowak

The purpose of this paper is to present an algorithm of the optimization of the dynamic parameters of an electromagnetic linear actuator operating in error‐actuated control system.

Abstract

Purpose

The purpose of this paper is to present an algorithm of the optimization of the dynamic parameters of an electromagnetic linear actuator operating in error‐actuated control system.

Design/methodology/approach

The elaborated “unaided” software consists of two main parts: optimization solver and numerical model of the actuator. Genetic algorithm has been used for optimization. The coupled field‐circuit‐mechanical model for the simulation of the system dynamics has been applied. Different optimization problems have been considered. The shape of the steady‐state force‐displacement actuator characteristic has been imposed and its deviation has been minimised. Next, the total operation time of the actuator without feedback, and the setup time of the actuator with feedback are minimised. Finally, required trajectory of movement has been imposed and trajectory error is minimised.

Findings

The elaborated algorithm and the computer code can be an effective tool for field‐circuit simulation of the dynamics of an electromagnetic linear actuator that operates in an automatic control system. It enables optimal design of the electromechanical system in respect to its dynamic properties.

Originality/value

The elaborated algorithm and the computer code presented in this paper can be an effective tool for the field‐circuit simulation of the dynamics of an electromagnetic linear actuator that operates in an automation control system.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 29 no. 1
Type: Research Article
ISSN: 0332-1649

Keywords

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Article
Publication date: 1 January 1992

Lech Nowak

An electromechanical converter supplied with the special feed systems which accelerate its operation in transient states is investigated. To solve the problem the…

Abstract

An electromechanical converter supplied with the special feed systems which accelerate its operation in transient states is investigated. To solve the problem the field‐circuit procedure is applied. The transients in an axisymmetric plunger‐type actuator with conducting core, after the application of supply voltage, taking the movement of some core parts into account are considered. The converter winding is composed of two coils connected with a system of external elements: resistors, capacitors and transistors.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 11 no. 1
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 1 December 2004

Lech Nowak, Andrzej Demenko and Wojciech Szeląg

This paper deals with a coupled field‐circuit simulation of transients in a three‐phase, three‐limb power transformer taking non‐linearity into consideration. A…

Abstract

This paper deals with a coupled field‐circuit simulation of transients in a three‐phase, three‐limb power transformer taking non‐linearity into consideration. A comparative analysis of the results obtained from the application of 3D and 2D field models has been carried out. Owing to core saturation and the non‐periodic components of the magnetic fluxes, the magnetic field exists also within the space surrounding the core. Hence, three‐dimensional description is necessary. It has been proved that assuming the 2D model significantly overstated peak values of currents are obtained.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 23 no. 4
Type: Research Article
ISSN: 0332-1649

Keywords

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