ArticleOriginal scientific text

Title

Estimation of coefficients of multivariable power series approximating magnetic nonlinearity of AC machines

Authors 1, 1

Affiliations

  1. Cracow University of Technology Institute of Electromechanical Energy Conversion ul. Warszawska 24, 31-155 Kraków, Poland

Abstract

Energy based approach was used in the study to formulate a set of functions approximating the magnetic flux linkages versus independent currents. The simplest power series that approximates field co-energy and linked fluxes for a two winding core of an induction machine are described by a set of common unknown coefficients. The authors tested three algorithms for the coefficient estimation using Weighted Least-Squared Method for two different positions of the coils. The comparison of the approximation accuracy was accomplished in the specified area of the currents. All proposed algorithms of the coefficient estimation have been found to be effective. The algorithm based solely on the magnetic field co-energy values is significantly simpler than the method based on the magnetic flux linkages estimation concept. The algorithm based on the field co-energy and linked fluxes seems to be the most suitable for determining simultaneously the coefficients of power series approximating linked fluxes and field co-energy.

Keywords

magnetism, magnetic field co-energy, mathematical modelling, parameters estimation

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