A Two-Dimensional Analytic Thermal Model for a High-Speed PMSM Magnet

Permanent-magnet synchronous machines (PMSMs) are well suited for high-speed (HS) applications due to their high efficiency, power density, and dynamic response capability. The heat extraction area decreases as the speed increases, making thermal effects more dominant at high speed. The temperature-dependent properties of permanent magnets necessitate high-detail thermal models. This paper presents a 2-D analytical model for a HS PMSM magnet. The diffusion equation is solved where three of the PM boundaries experience convection heat flow; as the case is in radial flux machines. The heat generated on the rotor surface due to eddy currents is also taken into account. The model is verified using numerical techniques and shows good correlation (within 1.5%). The model is also validated through experiments performed on a 4 kW, 30 000 r/min PMSM.

[1]  Frank P. Incropera,et al.  Fundamentals of Heat and Mass Transfer , 1981 .

[2]  Andrea Cavagnino,et al.  Conjugate Heat Transfer Analysis of Integrated Brushless Generators for More Electric Engines , 2014 .

[3]  Jan Abraham Ferreira,et al.  On the Speed Limits of Permanent-Magnet Machines , 2010, IEEE Transactions on Industrial Electronics.

[4]  D. R. Turner,et al.  Lumped parameter thermal model for electrical machines of TEFC design , 1991 .

[5]  Andre J. Grobler,et al.  Thermal modelling of a high speed permanent magnet synchronous machine , 2013, 2013 International Electric Machines & Drives Conference.

[6]  S. R. Holm,et al.  Analytical Modeling of a Permanent-Magnet Synchronous Machine in a Flywheel , 2007, IEEE Transactions on Magnetics.

[7]  N. Bianchi,et al.  Potentials and limits of high-speed PM motors , 2003, IEEE Transactions on Industry Applications.

[8]  N. Bianchi,et al.  Analysis and design of a PM Brushless Motor for high-speed operations , 2005, IEEE Transactions on Energy Conversion.

[9]  Antonios G. Kladas,et al.  Thermal Investigation of Permanent-Magnet Synchronous Motor for Aerospace Applications , 2014, IEEE Transactions on Industrial Electronics.

[10]  Yan Zhang,et al.  Production and Properties of Soft Magnetic Cores Made From Fe-Rich FeSiBPCu Powders , 2015, IEEE Transactions on Magnetics.

[11]  A. Binder,et al.  Analytical Calculations of Induced Eddy Currents Losses in the Magnets of Surface Mounted PM Machines With Consideration of Circumferential and Axial Segmentation Effects , 2012, IEEE Transactions on Magnetics.

[12]  A. Mebarki,et al.  Improved synchronous machine thermal modelling , 2008, 2008 18th International Conference on Electrical Machines.

[13]  J. C. Jaeger,et al.  Conduction of Heat in Solids , 1952 .

[14]  D. Rodger,et al.  Coupled electromagnetic-thermal modeling of electrical machines , 2003 .

[15]  Antonio Griffo,et al.  Derivation and Scaling of AC Copper Loss in Thermal Modeling of Electrical Machines , 2014, IEEE Transactions on Industrial Electronics.

[16]  David G. Dorrell,et al.  Linked electromagnetic and thermal modelling of a permanent magnet motor , 1988 .

[17]  Andrea Cavagnino,et al.  Evolution and Modern Approaches for Thermal Analysis of Electrical Machines , 2009, IEEE Transactions on Industrial Electronics.

[18]  Rafal Wrobel,et al.  Thermal Design of High-Energy-Density Wound Components , 2011, IEEE Transactions on Industrial Electronics.

[19]  B. Laporte,et al.  A combined electromagnetic and thermal analysis of induction motors , 2005, IEEE Transactions on Magnetics.

[20]  Andrea Cavagnino,et al.  Thermal model and analysis of wound rotor induction machine , 2012, 2012 IEEE Energy Conversion Congress and Exposition (ECCE).

[21]  C. Gerada,et al.  Electro-thermal combined optimization on notch in air cooled High Speed Permanent Magnetic Generator , 2016 .

[22]  D. Hong,et al.  Ultra High Speed Motor Supported by Air Foil Bearings for Air Blower Cooling Fuel Cells , 2012, IEEE Transactions on Magnetics.

[23]  Andrea Cavagnino,et al.  High-Speed Electrical Machines: Technologies, Trends, and Developments , 2014, IEEE Transactions on Industrial Electronics.

[24]  Hashem Oraee,et al.  Electromagnetic-Thermal Design Optimization of the Brushless Doubly Fed Induction Generator , 2014, IEEE Transactions on Industrial Electronics.

[25]  C. Gerada,et al.  Electrothermal Combined Optimization on Notch in Air-Cooled High-Speed Permanent-Magnet Generator , 2015, IEEE Transactions on Magnetics.

[26]  A. Boglietti,et al.  Impact of different end region cooling arrangements on endwinding heat transfer coefficients in electric motors , 2009, 2009 35th Annual Conference of IEEE Industrial Electronics.