Computation of iron losses in permanent magnet machines by multi-domain simulations

Nowadays the majority of electric drives work at variable speeds. In this kind of drives the electrical machines are supplied by inverters which generate modulated voltages. It is widely known that these non sinusoidal voltages cause additional current harmonics dealing to higher iron losses than with sinusoidal voltages. The iron losses affect to several design constraints as the efficiency and the thermal behavior of electrical machine. Hence, the accurate computation of the iron losses under different supply voltage conditions is very important in order to optimize the machine design as much as possible. This work deals with multi-domain simulations in order to calculate the iron losses in permanent magnet synchronous machines (PMSM) under Pulse Width Modulated (PWM) voltages. The current supplies are implemented in the simulation system MATLAB-SIMULINK^reg. Whereas the electrical machine is simulated using the Finite Element Method (FEM). The iron losses are computed by a post-processing analysis carried out using the tool so called Loss Surface Model (LSM) which is integrated in the FEM software FLUX^reg of Cedrat. Finally, experimental tests are performed in order to validate the proposed methodology.