Experimental Study of Iron Losses Generated by a Uniform Rotating Field

Alix Bernot (1) , Alexandre Giraud (1, 2, 3) , Yvan Lefèvre (3) , Jean-François Llibre (3)

1 IRT Saint Exupéry - Institut de Recherche Technologique
2 LAPLACE - LAboratoire PLasma et Conversion d'Energie
3 LAPLACE-GREM3 - Groupe de Recherches en Electrodynamique

This paper introduces a mock-up with a solid iron cylinder rotating in a fixed excitation frame powered by dc current. A uniform field is created in the rotating cylinder, which is driven by an external motor. The braking torque is measured, allowing the study of iron losses generated by a uniform rotating field. The aim is to advance toward a vector iron loss model that takes into account different magnetization directions and their interdependency. The eddy current losses are the dominant loss source in the mock-up, rendering it easier to model. A standard eddy currents model is proposed. It models well the losses at low and medium magnetic flux density, but lower losses are measured near saturation levels. This could be due to the high thickness to radius ratio changing the eddy current paths near the edges of the rotor, which can be later analyzed by a full 3-D finite-element method analysis. A 2-D finite-element method simulation is performed, which estimates the magnetic flux heterogeneity in the rotor. Several lessons are drawn from this mock-up, which prepares a second version with a higher speed and a longer laminated stack rotor. A higher air gap will decrease the voltage fluctuation in the primary winding, a smaller angular opening of the excitation frame will improve the uniformity of the flux in the rotor.

Mots clés: Eddy currents; Iron losses; Rotating field; Rotational losses

Domaines: Electromagnétisme; Energie électrique; Plasmas

Alix Bernot, Alexandre Giraud, Yvan Lefèvre, Jean-François Llibre. Experimental Study of Iron Losses Generated by a Uniform Rotating Field. IEEE Transactions on Magnetics, 2017, 53 (11), pp.6300705. ⟨10.1109/TMAG.2017.2707542⟩. ⟨hal-01652370⟩