Affiliations: [a] Electromagnetic Division, Istituto Nazionale di Ricerca Metrologica, Torino, Italy | [b] Dipartimento Energia, Politecnico di Torino, Torino, Italy | [c] Dip. Ing. dell'Energia Elettrica e dell'Informazione, Università di Bologna, Bologna, Italy
Correspondence:
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Corresponding author: Mauro Zucca, Electromagnetic Division, Istituto Nazionale di Ricerca Metrologica (INRIM), Strada delle Cacce 91, Torino, Italy. Tel./Fax: +39 011 3919827; E-mail:m.zucca@inrim.it
Abstract: This paper aims at analyzing electric motor-generators
specifically designed for the avionics application in More Electric Aircraft,
where the machine is included inside the main gas turbine. Because of the
harsh environment the problem of evaluating and reducing the losses produced
in these machines becomes crucial. For such a purpose, this paper presents
an accurate estimate of the magnetic and Joule losses produced inside the
machine, when operating as generator in a range of frequencies from 200 Hz
up to 400 Hz. Particular attention is paid to the investigation of the
effects introduced by the use of a high number (6 and 12) of phases, due to
fault tolerance reasons. The analysis is developed on a small (10 kW)
prototype, consisting of a four-pole twelve-phase induction machine. The
numerical computations are performed through a validated 2-D finite element
code, based on a step-by-step procedure and on the sliding mesh technique. A
sophisticated laminated dynamic Preisach model, whose parameters are
identified from a large set of measurements, provides an accurate estimate
of the iron losses and their separation into the three fundamental
components also under skin effect regime. The results show that six and
twelve phase configurations produce significant loss decrease.
Keywords: Electromagnetic modeling, fault tolerant systems, induction machines, magnetic losses
