Core Loss Prediction in Electrical Machine Laminations Considering Skin Effect and Minor Hysteresis Loops

This paper presents a method for the estimation of core losses in electrical machine laminations exposed to high-frequency and nonsinusoidal excitations by using only low-frequency measurements. The developed model takes into account the nonuniform distribution of the magnetic field inside the lamination. Accurate core loss prediction in the presence of minor loops is achieved using the energetic model to calculate the quasi-static hysteresis loops. The results are verified experimentally by comparing to the measured core losses in laminations exposed to the flux waveforms in different sections of an inset permanent magnet machine. The comparison between measured and calculated core losses shows excellent agreement, confirming the validity of the model.

[1]  T.J.E. Miller,et al.  On the variation with flux and frequency of the core loss coefficients in electrical machines , 2006, IEEE Transactions on Industry Applications.

[2]  C. Ragusa,et al.  Predicting loss in magnetic steels under arbitrary induction waveform and with minor hysteresis loops , 2004, IEEE Transactions on Magnetics.

[3]  Hans Hauser,et al.  Energetic model of ferromagnetic hysteresis: Isotropic magnetization , 2004 .

[4]  Yu Zhang,et al.  Magnetic Characteristics and Core Losses in Machine Laminations: High-Frequency Loss Prediction From Low-Frequency Measurements , 2012, IEEE Transactions on Industry Applications.

[5]  Paavo Rasilo,et al.  Model of laminated ferromagnetic cores for loss prediction in electrical machines , 2011 .

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

[7]  C. Steinmetz.  On the Law of Hysteresis , 1984, Transactions of the American Institute of Electrical Engineers.

[8]  M. Cheng,et al.  General core loss models on a magnetic lamination , 2009, 2009 IEEE International Electric Machines and Drives Conference.

[9]  P. Pillay,et al.  Physical Basis for the Variation of Lamination Core Loss Coefficients as a Function of Frequency and Flux Density , 2006, IECON 2006 - 32nd Annual Conference on IEEE Industrial Electronics.

[10]  P. Marketos,et al.  Loss Separation in Nonoriented Electrical Steels , 2010, IEEE Transactions on Magnetics.

[11]  F. Preisach.  Über die magnetische Nachwirkung , 1935 .

[12]  M. L. Hodgdon,et al.  Mathematical theory and calculations of magnetic hysteresis curves , 1988 .

[13]  G. Jewell,et al.  Prediction and measurement of core losses in a high-speed switched-reluctance Machine , 2005, IEEE Transactions on Magnetics.

[14]  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).

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

[16]  D. Jiles,et al.  Theory of ferromagnetic hysteresis , 1986 .

[17]  Todd Litman,et al.  Energy-Efficient Electric Motor Selection Handbook , 1990 .

[18]  W. F. Weldon,et al.  Determination of iron core losses under influence of third-harmonic flux component , 1991 .

[19]  Maurizio Repetto,et al.  Modeling of electromagnetic phenomena in soft magnetic materials under unidirectional time periodic flux excitations , 1999 .

[20]  P. Pillay,et al.  Novel equipment for the measurement of core losses in laminations for advanced machines , 2011, 2011 IEEE International Electric Machines & Drives Conference (IEMDC).

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