A calculation of the magnetic characteristics of surface mounted PMSMs under heavy load conditions considering the cross-magnetizing effect

Resumen:
In this paper, an analytical method to obtain the magnetic flux in the air gap and the flux densities in surface mounted permanent magnet synchronous machines is described. The particularity of the method, which is based on the magnetic lumped parameter circuit approach, is that it is capable of predicting the magnetic decrease in the air gap due to the cross coupling between the d-axis and the q-axis (cross-magnetizing effect), shifting the angle of the magnetic axis. Moreover, the presented method can also evaluate the local flux density level at the sides of the pole magnets, which is very useful for preventing local magnet demagnetization at load conditions. The methodology is compared with Finite Element Method based simulations, with very good results.