Zbigniew Gmyrek
University of Łódź
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Featured researches published by Zbigniew Gmyrek.
IEEE Transactions on Industrial Electronics | 2010
Zbigniew Gmyrek; Aldo Boglietti; Andrea Cavagnino
This paper intends to develop a more accurate approach for determining the no-load iron losses in pulse width modulation (PWM) inverter fed induction motors. The proposed method is validated by means of a prototype motor with a plastic rotor cage. The iron losses have been computed by the time-stepping finite element method, both with sinusoidal and PWM supply. The iron losses have then been estimated by adding up the contribution generated by orthogonal components of the flux density, as if the iron losses generated by these components were independent phenomena. The rotational hysteresis losses, as well as excess ones, have been calculated applying a correction factor based on experimental data. These factors are a function of the peak flux density and ellipticity of the B vector loci. Experimental validations are provided for several frequency and magnetic saturation values. In addition, this paper demonstrates the necessity to consider the harmonics initial phase in order to increase the accuracy in the iron loss prediction.
IEEE Transactions on Industrial Electronics | 2008
Zbigniew Gmyrek; Aldo Boglietti; Andrea Cavagnino
In this paper, two different methods for iron loss prediction are analyzed. The first method is based on the classical separation of loss contributions (hysteresis, eddy-current, and excess losses). The model requires loss contribution separation using iron loss measurements with sinusoidal supply. In this paper, this method will be called the ldquolow-frequency method.rdquo The second method, named the ldquohigh-frequency method,rdquo is based on the assumption that, under pulsewidth modulation supply, the higher order flux density harmonics do not influence the magnetic work conditions. These magnetic conditions depend only on the amplitude of the fundamental harmonic of the flux density. In this paper, both the proposed methodologies and the related measurements are described in detail, and the obtained results are compared with the experimental ones. The experimental results show that both methods allow getting excellent results. The high-frequency method is better than the lower one but requires a more complex test bench. Depending on the accuracy required by the user, the more handy method can be chosen, with the guarantee that the estimation errors will be lower than 5%.
IEEE Transactions on Industry Applications | 2013
Zbigniew Gmyrek; Andrea Cavagnino; Luca Ferraris
This paper presents a method to estimate the magnetic properties and width of a damaged area which is the result of the carried out punching process. Both a finite-element method (FEM) numerical model and a method for estimating the damaged area width are proposed based on data obtained from the noninvasive measurements as well as on an experimental study of the crystallographic structure. In addition, the authors propose an algorithm, using the FEM numerical model, to identify the equivalent magnetic properties of the material in the damaged area. The results obtained from the FEM model were compared with those obtained by the analytical formula proposed earlier.
conference of the industrial electronics society | 2011
Zbigniew Gmyrek; Andrea Cavagnino
The authors deal with the problem of estimating the zone width of damaged magnetic materials, which is the result of industrial processes adopted for the lamination sheet production. The authors propose two approaches: the former uses the 3D FEM model, while the latter proposes an analytical formula. Both approaches use the results of measurements performed on toroidal samples. The final result of the study is the comparison between the width of the damaged zone computed with the two proposed approaches and the comparison between the calculated and measured power losses.
conference of the industrial electronics society | 2006
Zbigniew Gmyrek; Aldo Boglietti; Andrea Cavagnino
In the paper two different methods for the iron loss prediction are analyzed. The first method is based on the classical separation of the loss contributions (hysteresis, eddy current and excess losses). The model requires the loss contribution separation using iron losses measurements with sinusoidal supply. In the following this method will be pointed out as low frequency method. The second method, in the following named high frequency method, is based on the assumption that, under PWM supply, the higher order flux density harmonics do not influence the magnetic work conditions. These magnetic conditions depend only on the amplitude of the fundamental harmonic of the flux density. In the paper both the proposed methodologies and the related measurements are described in detail and the obtained results are compared with the experimental ones. The experimental results show that both the methods allow to get excellent results. The high frequency method is better the lower one but required a more complex test bench. Depending on the accuracy required by the user, the more handy method can be chosen having the guarantee that the estimation errors will be lower than 5%
international conference on electrical machines | 2008
Zbigniew Gmyrek; Aldo Boglietti; Andrea Cavagnino
In this paper the iron losses in induction motors are estimated and analysed using time-stepping Finite Element Method (FEM) both with sinusoidal and PWM supply. The iron losses calculation has been carried out by add up the iron losses produced by orthogonal components of the flux density, as if the iron losses produced by these components were independent phenomena. The rotational hysteresis loss has been calculated applying a correction factor based on experimental data. This factor is a function of the peak flux density value and of the major and minor axis of the B loci. The experimental validations are provided for several frequencies and saturation levels.
conference of the industrial electronics society | 2011
Zbigniew Gmyrek; Aldo Boglietti; Andrea Cavagnino
In the paper an accurate analysis of the different loss contributions active during no-load operations of PWM inverter fed induction motors is presented. In particular, the paper is focused onto the understanding and quantification of the loss growth passing from sinusoidal to PWM supply. Standard no-load tests have been performed on an 11kW, squirrel cage, induction motor to collect reference loss data to be compared with the computed one. The loss estimations have been done using two different approaches. The former is a 3D, time-stepping, FEM model, while the latter is a simplified analytical, experimental data-based approach recently proposed by the authors. Both numerical and semi-analytical methodology lead to accurate results with estimation percentage errors lower than 5 % in the considered voltage range.
Compel-the International Journal for Computation and Mathematics in Electrical and Electronic Engineering | 2009
Zbigniew Gmyrek
Purpose – The purpose of this paper is to discuss a new method of iron loss estimation under pulse width modulation (PWM) converter supply. The proposed method concerns the longitudinal magnetisation.Design/methodology/approach – A novel method of iron loss estimation applies values of iron losses that come from a single higher harmonic coexisting with a DC‐bias field. This method considers non‐linearity of ferromagnetic. Results of estimation are validated using experimental results.Findings – The paper formulates that the dependence of iron losses come from harmonics, on DC‐bias field. Moreover, it formulates possibilities of their utilization to iron loss estimation in case of deformed flux. On the other hand, it discusses the influence of DC‐bias field on static hysteresis and classical eddy current losses.Research limitations/implications – Experimental verification will still be needed as to the accuracy of the proposed model and applicability to various magnetic materials.Practical implications – T...
Archive | 2005
Jan Anuszczyk; Zbigniew Gmyrek
A special problem is the calculation of power loss in the core of rotating electrical machines because the magnetic fields occuring in the core are neither unidirectional nor sinusoidal. This paper discusses the calculation of rotational power losses. Several methods have been proposed for this purpose. Among these, the method based on calculation of the field quantities Bx and By is described. In this method the rotational power losses are calculate employing empirical approach directly from these quantities. The main point of presented method is creating of calculation model to calculate components of the flux density vector ( module and argument ) in every elements of the mesh representing the magnetic circuit of tested material. Beside this, the excess losses are calculate using statistical theory proposed by Bertotti.
Compel-the International Journal for Computation and Mathematics in Electrical and Electronic Engineering | 2007
Jan Anuszczyk; Zbigniew Gmyrek; Grzegorz Zwoliński
Purpose – The calculation of the power loss in the core of the electrical machines is a special problem. In some areas of the electrical machine core the magnetic fields are neither unidirectional nor sinusoidal. This paper seeks to discuss the rotational power loss calculation methodology.Design/methodology/approach – The proposed methodology is based on the calculation of the field quantities Bx and By. In this methodology the rotational power losses are calculated employing the empirical approach directly from these quantities. Moreover, the computational model is the most important element of the proposed methodology because it utilises the FEM to the calculations of the hodographs of the flux density vector in each mesh element.Findings – The paper formulates the dependence of the rotational power losses from the B vector hodograph shape.Research limitations/implications – Experimental verification will still be needed as to the accuracy of the model and the applicability to the various magnetic mate...