This paper deals with an induction machine whose squirrel cage is made of copper obtained by die casting process. The major issue of this process is the thermal shock suffered by the laminations, leading to the deterioration of insulation coating as well as the generation of interbar currents, those currents being responsible for addition stray losses. This issue can be counteracted by using grain oriented laminations on the rotor. In particular, the paper highlights that due to the specificity of the insulation coating of that kind of electrical steel it does not suffer from the thermal shock. It is shown that using a squirrel cage made of copper combined to grain oriented laminations in the rotor leads to a decrease of both core losses and stray load losses and an increase of the efficiency of 1.6%.

This paper deals with Life Cycle Assessment (LCA) of induction machines and try to determine whether a coppercage rotor is better than an aluminium-cage one, for a given using time and considering the global environmental footprint. The paper focuses on induction motors directly connected to the power grid, without electronic converters. The LCA takes into account the materials extraction, the machine construction, the use and the end of life for several criteria. In the first part, a copper conductor is compared to an aluminium one and results are discussed considering the part of recycled material in the rotor manufacturing process. In a second part, two machines with the same efficiency are compared. The environmental impacts differences are discussed. In the third part, two machines of the same sizes, but with a different rotor, are compared considering various usage times. The lower losses of the copper-rotor machine yield a significant advantage for the efficiency but the gains are smaller when the global life cycle is considered.

In order to increase energy efficiency of AC rotating machines, one possibility is the use of Grain-Oriented steel sheets to build stator magnetic circuits in order to reduce iron losses. After presenting the general concept considering a non-segmented-shifted sheets prototype recently developed in our laboratory, a segmented structure is introduced. Experimental comparisons between these structures are performed using static machines. The main results are analysed using Finite Element modelling that leads to extract the particular physical concepts which govern these associations.

This paper deals with an induction machine whose squirrel cage is made of copper obtained by die casting process. The major issue of this process is the thermal shock suffered by the laminations, leading to the deterioration of insulation coating as well as the generation of interbar currents, those currents being responsible for addition stray losses. This issue can be counteracted by using grain oriented laminations on the rotor. In particular, the paper highlights that due to the specificity of the insulation coating of that kind of electrical steel it does not suffer from the thermal shock. It is shown that using a squirrel cage made of copper combined to grain oriented laminations in the rotor leads to a decrease of both core losses and stray load losses and an increase of the efficiency of 1.6%.