A simple induction machine model for predicting low frequency dynamics

Conventional models of induction machine for steady-state and dynamic analysis use fixed value of the rotor resistance; whereas for representing the deep-rotor-bar effect a second rotor branch is typically required therefore increasing the model complexity and order. This paper proposes a simple but very effective modification of traditional model, wherein a single-branch rotor resistance is changed as a function of speed. The new model parameters are readily identified using standard experiments and tests. Experimental results and simulation studies demonstrate the improved accuracy and advantage of the proposed model in predicting the low-frequency transients. More importantly, the improvement is achieved without increasing the model order.