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Printed circuit board (PCB) stators in coreless axial flux permanent magnet (AFPM) machines have been proposed, designed, and studied for use in multiple industries due to their design flexibility and reduction of manufacturing costs, volume, and weight compared to conventional stators. This paper investigates mechanisms and methods of approximating open circuit losses in PCB stators within example wave and spiral winding topologies for a dual rotor, single stator configuration using 3D FEA, analytical hybrid techniques and experiments. The effect of rotor magnet shape, end winding, and active conductor geometry on eddy currents is studied, and some mitigation techniques are proposed. Through stator equivalent circuit analysis, circulating current losses caused by mechanical abnormalities and magnetic circuit asymmetry are assessed. Possible strategies and schemes to minimize circulating current losses are also described. The trade-off between stator loss components and some practical design considerations are outlined in detail. The open circuit power losses of a prototype coreless AFPM motor were experimentally tested using multiple example PCB stators and emulated rotor asymmetries, with the findings being comparable to the FEA and hybrid analytical methods results.

Interior permanent magnet (IPM) motors are increasingly being used to replace induction motors in electronically controlled variable speed applications. Brushless permanent magnet motors offer superior performance in terms of increased efficiency and noise reduction. IPM motors, on the other hand, the advantage of better demagnetization.

In the paper a comparison between the analytical and numerical method of no-load computation will be made taking into account the initial hypothesis and computational effort face to the concrete obtainable results. It is concluded that the reduced fixed-mesh FEM analysis of the induction motors is very suitable for no-load computation because it relates directly to the well known equivalent circuit parameters. The symmetry of the machine allows for the computation only on a small part of the magnetic circuit so that the time of computation can be reduced even when a relatively fine mesh is used. However, for the optimal design of the motor it appears that analytical methods are very suitable owing to the simplicity and accuracy of the design. [ABSTRACT FROM AUTHOR]