Modelling and stability analysis of a permanent-magnet synchronous machine taking into account the effect of cage bars

Several methods have been investigated for the computational and experimental determination of static and dynamic parameters of permanent-magnet synchronous machines, based on a sixth-order-transient two-axis model including the effect of cage bars. In addition to reviewing and comparing established methods, some new techniques are proposed with special emphasis on the determination of stator leakage inductance and cage-bar parameters, by computation and experiment. The equivalent-circuit model developed is suitable for the analysis of both steady-state and dynamic behaviour. The results from different methods are compared. The model is used to investigate the open-loop stability of the machine´s operation by means of computer simulation and experiment. The good agreement between simulated and experimental results for stability boundaries confirms the validity of the proposed modelling methods