Effects of PWM excitations on iron loss in electrical steels and machines

The iron loss in the ferromagnetic cores of electrical machines under PWM excitations could be many times higher than the loss under sinusoidal excitation. Therefore, the effects of the PWM waveforms, and their various characteristics (modulation index, switching frequency, and topology, etc.), on the iron loss must be understood and the ability to model these effects in the electrical machine design process is highly desired. In this work, the iron loss is reported for various electrical steels under PWM excitations and the effects of PWM waveform characteristics are studied. The iron loss measurements in a surface mounted permanent magnet motor under PWM excitations are also presented and are in agreement with the measured iron losses in electrical steels. The effect of the iron loss variations on the operating point of the machine is also discussed from the electric vehicle point of view. In the end, a computationally efficient approach based on the static Preisach model is presented to predict the iron loss in electrical steels. The proposed approach can model the effects of changing switching frequency, switching topology and modulation index on the iron loss with a reasonable accuracy.

[1]  Chas.P. Steinmetz,et al.  On the law of hysteresis , 1984, Proceedings of the IEEE.

[2]  Torsten Bertram,et al.  Use of Jiles–Atherton and Preisach Hysteresis Models for Inverse Feed-Forward Control , 2010, IEEE Transactions on Magnetics.

[3]  A. Boglietti,et al.  Iron Loss Prediction with PWM Supply: An Overview of Proposed Methods from an Engineering Application Point of View , 2007, 2007 IEEE Industry Applications Annual Meeting.

[4]  P. Pillay,et al.  Comparison of lamination iron losses supplied by PWM voltages: US and European experiences , 2005, IEEE International Conference on Electric Machines and Drives, 2005..

[5]  David A. Lowther,et al.  The prediction of iron losses under PWM excitation using the classical Preisach model , 2016 .

[6]  Anthony John Moses,et al.  Dynamic hysteresis modelling , 2004 .

[7]  Kieran Humphries,et al.  Design and optimization of fractional slot concentrated winding permanent magnet machines for class IV electric vehicles , 2016, 2016 IEEE Transportation Electrification Conference and Expo (ITEC).

[8]  Antero Arkkio,et al.  Inverted and forward preisach models for numerical analysis of electromagnetic field problems , 2006, IEEE Transactions on Magnetics.

[9]  G. Bertotti.  Hysteresis in Magnetism: For Physicists, Materials Scientists, and Engineers , 1998 .

[11]  R. Kaczmarek,et al.  Prediction of power losses in silicon iron sheets under PWM voltage supply , 1994 .

[12]  H. Trabelsi,et al.  Calculation of magnetic fields and iron losses in a SMPM by using vector Preisach model and transient finite element analysis , 2008, 2008 5th International Multi-Conference on Systems, Signals and Devices.

[13]  P. Marketos,et al.  Iron losses under PWM excitation using a dynamic hysteresis model and finite elements , 2006, IEEE Transactions on Magnetics.

[14]  I. Mayergoyz,et al.  Generalized Preisach model of hysteresis , 1988 .

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

[16]  Benoit Boulet,et al.  Implementation of a bidirectional DC-DC in electric powertrains for drive cycles used by medium duty delivery trucks , 2015, 2015 IEEE Energy Conversion Congress and Exposition (ECCE).

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

[18]  Kieran Humphries,et al.  Comparison of fractional-slot concentrated winding and PM-assisted synchronous reluctance motors for class IV electric vehicles , 2017, 2017 IEEE International Electric Machines and Drives Conference (IEMDC).

[19]  O. Bottauscio,et al.  Numerical Investigation of the Effects of Loading and Slot Harmonics on the Core Losses of Induction Machines , 2012, IEEE Transactions on Magnetics.

[20]  Rik W. De Doncker,et al.  Advantages of a variable DC-link voltage by using a DC-DC converter in hybrid-electric vehicles , 2010, 2010 IEEE Vehicle Power and Propulsion Conference.