A nonlinear saturation model for salient-pole synchronous machines in high performance drive applications

This paper developed an enhanced saturation model for wound-rotor salient-pole synchronous machines based on experimental evaluation and analysis. The new model uses three nonlinear lumped-parameter impedances to fully characterize the magnetic saturation phenomenon. They characterize respectively the d-axis saturation, the q-axis saturation, and the nonlinear coupling between the field and the stator windings due to the saturation. Without losing the physical meaning inherent of d-q based model, the enhanced model is especially convenient for implementation and tuning in drive controllers based on the field-oriented algorithm. Simulation and experimental results showed improved drive control accuracy and dynamic performance. Finite element analysis confirmed adequacy of the modeling approach.