Factors Affecting the Accurate Prediction of Iron Losses in Electrical Machines

A model of core losses, in which the hysteresis coefficients are variable with the frequency and induction (flux density) and the eddy-current and excess loss coefficients are variable only with the induction, is proposed. A procedure for identifying the model coefficients from multi-frequency Epstein tests is described and examples are provided for three typical grades of non grain-oriented laminated steel suitable for electric motor manufacturing. Over a wide range of frequencies between 20 Hz and 400 Hz and inductions from 0.05 T up to 2 T the new model yielded much lower errors for the specific core losses than conventional models. The applicability of the model for electric machine analysis is also discussed and examples from an interior permanent and an induction motor are included

[1]  G. Slemon,et al.  Core losses in permanent magnet motors , 1990, International Conference on Magnetics.

[2]  Phil Mellor,et al.  Calculation of iron losses from time-stepped finite-element models of cage induction machines , 1995 .

[3]  Andrea Cavagnino,et al.  Predicting iron losses in soft magnetic materials with arbitrary voltage supply: an engineering approach , 2003 .

[4]  N. Takahashi,et al.  Investigation of benchmark model for estimating iron loss in rotating machine , 2004, IEEE Transactions on Magnetics.

[5]  F. Fiorillo,et al.  An improved approach to power losses in magnetic laminations under nonsinusoidal induction waveform , 1990 .

[6]  T.J.E. Miller,et al.  High-speed PC-based CAD for motor drives , 2002 .

[7]  Timothy J. E. Miller,et al.  Design of Brushless Permanent-Magnet Motors , 1994 .

[8]  K. Atallah,et al.  AN improved method for predicting iron losses in brushless permanent magnet DC drives , 1992, 1992. Digests of Intermag. International Magnetics Conference.

[9]  Tim C. Green,et al.  Estimating rotational iron losses in an induction machine , 2003 .

[10]  M. Chiampi,et al.  An improved estimation of iron losses in rotating electrical machines , 1991 .

[11]  Alexander C. Smith,et al.  Influence of manufacturing processes on iron losses , 1995 .

[12]  P. Pillay,et al.  An improved formula for lamination core loss calculations in machines operating with high frequency and high flux density excitation , 2002, Conference Record of the 2002 IEEE Industry Applications Conference. 37th IAS Annual Meeting (Cat. No.02CH37344).

[13]  G. Bertotti.  General properties of power losses in soft ferromagnetic materials , 1988 .

[14]  K. Blazek,et al.  New magnetic parameters to characterize cold-rolled motor lamination steels and predict motor performance , 2004, IEEE Transactions on Magnetics.

[15]  P. Biringer,et al.  A simple method of estimating the minor loop hysteresis loss in thin laminations , 1978 .