Induction motor parameter identification based on T-model equivalent circuit

In this paper the relationship between induction motor port impedance and internal parameters including stator inductance, rotor inductance, magnetizing inductance and rotor resistance is deduced based on T-model equivalent circuit. The relationship explains the reason that every internal parameter can not be uniquely identified with the port impedance, and rotor speed or frequency. The minimum parameters set of T-model equivalent circuit is proposed based on this deduce. Two methods of calculating the minimum parameters set applied for rotation and locked-rotor conditions respectively are proposed. In order to analyze the influence of iron loss on the motor parameters, a simplified T-model equivalent circuit, suitable for low frequency environment, is presented. The effectiveness of the model and the two methods proposed are verified with the experimental results.