Impact of mechanical stresses on the magnetic performance of non-oriented electrical steels and its relation to electric machine efficiency

In the search for higher efficiency machines, the use of new topologies and better electrical steels in the rotor and/or stator stack are part of the solutions envisaged. ArcelorMittal has developed a range of low loss and high permeability grades that can fit this purpose. This paper quantifies the effect of mechanical stresses on the magnetic properties of such an electrical steel stack. These stresses can be due to electromagnetic phenomena, but also due to production methods of the machine. Both the impact of elastic and plastic stresses are being verified on the magnetic property degradiation. Such information is important to maximise the electrical steels' potential, hence to find a globally optimised machine solution, in terms of the chosen electromagnetic core materials and their utilisation method.