Measurement and Modeling of No-Load Losses of an Axial Flux Machine with Round and Flat Wires

This paper addresses the measurement and modeling of no-load losses of a double stator-single rotor axial flux permanent magnet machine. An 18-slot/12-pole configuration with open slots and tooth coils is considered. Several configurations are tested to evaluate different no-load losses such as mechanical losses, magnet losses, rotor holder losses, stator iron losses as well as AC losses due to the proximity effect caused by the external magnetic field generated by the rotation of the magnets. The rotor losses in the magnet and rotor holder are evaluated by measuring the rotor temperature with an infrared sensor. Using both experimental and simulation methods, round and flat wire winding configurations are studied and compared in terms of AC losses. To achieve the best prediction of iron losses, the specific iron losses are evaluated using the stator yoke of the axial flux machine as a torus test. Finally, the simulated losses obtained by 3D and 2D finite element analysis are compared with the measured losses.