Utilisation of grain-oriented electrical steel in permanent magnet fractional-slot modular machines

The performance improvement of using grain-oriented electrical steels (GOES) in the stator of PM fractional-slot modular machines is analysed in this study. Several models using a finite element tool are examined and it is concluded the techniques used in the actual software are not accurate for simulating anisotropic behaviour. Consequently, a simplified yet accurate modelling technique is proposed to simulate the performance of this type of electrical machines equipped with GOES. The advantages as well as the drawbacks of using GOES on the electromagnetic performance are investigated for different pole/slot combinations. It is concluded that the use of GOES is beneficial from an electromagnetic point of view mainly due to an increase on the radial component of the airgap flux density.