Practical modelling of permanent magnet synchronous machines with rare-earth magnets

In high-field machines employing rare-earth magnets the effect of saturation is significant, and therefore appropriate modification to the classic two-reaction theory has to be considered to achieve more accurate and realistic prediction of the machine performance. Two approaches are described for modelling the steady-state operation of permanent magnet synchronous machines from the two-reaction equivalent circuit which take into account the effect of core loss. The nonlinearity of the machine´s performance due to saturation is taken into account by adjusting the values of the synchronous reactances. Experimental results confirm the validity and accuracy of the model. In addition, the sensitivity of the analysis to the values of the two-reaction equivalent circuit parameters is investigated.<>