Improved modelling of PMSMs taking into account conductive rotor parts

Abstract

Permanent-magnet synchronous machines (PMSMs) are increasingly being used, not only in robotics but also in many other drives such as for traction, heat, ventilation and air-conditioning applications as an alternative for the induction machine. Advanced control of those PMSMs can require a machine model and a appropriate method to identify the model parameters. In conventional models, the only conductive part modelled is the stator winding. In this paper, a model for the PMSM is proposed that takes into account the conductive parts in the rotor as well, such as the electric steel laminations and the permanent magnets itself. These parts are represented by an equivalent winding. Further, the parameter identification of this model is discussed and the results are presented. As PMSMs operate at a variable magnetic state, the influence of magnetic saturation on the estimated electrical parameters is discussed.