Modelling and simulating saturation in main and leakage flux paths of induction machines

This paper discusses a new nonlinear analytical model for induction machines that takes into account the variable magnetic state of main as well as leakage flux paths. For this purpose, magnetizing flux as well as rotor and stator leakage fluxes are given as nonlinear functions of the currents flowing in the stator and rotor. By using this model, the transient states of the induction machine can be modelled more accurately compared to the conventional linear model. This is of importance for sensorless control of heavy-loaded induction machines often operating in transient mode. To verify the model, a comparison is made of simulation results for a 3 kW series-produced induction machine. Simulations are performed at steady-state as well as transient state