Optimization of magnets segmentation for eddy current losses reduction in permanent magnets electrical machines

Magnet segmentation is an effective and simple technique for eddy current losses reduction in high power permanent magnets electrical machines. This work aims to study the magnets segmentation effects on eddy current losses in magnets. First, an analysis of eddy currents and associated losses in magnets is made. After, the magnets segmentation effects on losses reduction in the range of the industrial frequencies from few Hz to dozen of kHz are investigated. To achieve these tasks, a 2D non linear model based on finite element analysis is developed under MATLAB environment. The developed model is applied to a synchronous machine with surface mounted permanent magnets. In a second part of the work, we have adopted an optimization process which consists to associate the finite element analysis to genetic algorithm. In this stage of the work, we aim to find the best parameters of magnets segmentation and avoid any segmentations anomaly that appears under some conditions such as skin effect, and which can leads to losses increases instead of their reduction.

[1]  D. Howe,et al.  Effect of Axial Segmentation of Permanent Magnets on Rotor Loss in Modular Permanent-Magnet Brushless Machines , 2007, IEEE Transactions on Industry Applications.

[2]  Mahdi Ashabani,et al.  Multiobjective Shape Optimization of Segmented Pole Permanent-Magnet Synchronous Machines With Improved Torque Characteristics , 2011, IEEE Transactions on Magnetics.

[3]  N. Takorabet,et al.  Effect of magnet segmentation on the cogging torque in surface-mounted permanent-magnet motors , 2006, IEEE Transactions on Magnetics.

[4]  Jean-Claude Vannier,et al.  Optimization of Magnet Segmentation for Reduction of Eddy-Current Losses in Permanent Magnet Synchronous Machine , 2010, IEEE Transactions on Energy Conversion.

[5]  P. Sergeant,et al.  Segmentation of Magnets to Reduce Losses in Permanent-Magnet Synchronous Machines , 2008, IEEE Transactions on Magnetics.

[6]  Yacine Amara,et al.  Analytical Prediction of Eddy-Current Loss in Armature Windings of Permanent Magnet Brushless AC Machines , 2010, IEEE Transactions on Magnetics.

[7]  K. Yamazaki,et al.  Effect of Eddy Current Loss Reduction by Segmentation of Magnets in Synchronous Motors: Difference Between Interior and Surface Types , 2009, IEEE Transactions on Magnetics.

[8]  Michel Bierlaire,et al.  Introduction à l"optimisation non linéaire , 2001 .

[9]  Damijan Miljavec,et al.  Eddy current losses in permanent magnets of the BLDC machine , 2007 .

[10]  K. Yamazaki,et al.  Loss Investigation of Interior Permanent-Magnet Motors Considering Carrier Harmonics and Magnet Eddy Currents , 2009, IEEE Transactions on Industry Applications.

[11]  A. Binder,et al.  3D analysis of circumferential and axial segmentation effect on magnet eddy current losses in permanent magnet synchronous machines with concentrated windings , 2010, The XIX International Conference on Electrical Machines - ICEM 2010.