Main flux‐saturation modelling ind‐qaxis models of induction machines using mixed current‐flux state‐space models

Abstract Main flux saturation in induction machines is most frequently modelled by selecting either stator and rotor d‐q axis currents or stator and rotor d‐q axis flux linkages as state‐space variables. This paper deals with so‐called mixed current‐flux state‐space models where either stator or rotor current space phasor is selected as one state‐space variable. The other state‐space variable is one of the three flux‐linkage space phasors in the machine (stator, magnetizing or rotor), so that six different state‐space models are encompassed. A generalised derivation procedure for all the six models is at first presented. Models are further given in developed form. It is shown that cross‐saturation effect is explicitly present in all the models. Derivation procedure and the models are verified by simulation and experimental investigation of induction generator self‐excitation.