Combined impact of iron loss and main flux saturation on operation of vector controlled induction machines

The paper analyses the combined impact of iron loss and main flux saturation on the behaviour of rotor flux-oriented induction machines. It discusses experimental identification of relevant parameters, evaluation of detuning in steady-states and transients and development of a modified rotor flux estimators aimed for compensation of the detuning. The experimental identification consists of a series of no-load tests conducted at various fundamental frequencies and flux levels. Utilising the developed procedure, variations of equivalent iron loss resistance with frequency and variations of magnetising inductance with magnetising current are calculated. A detailed detuning study is further performed on a 4 kW machine.