Auto-tuning Rotor Resistance Identification of Induction Motor Considering Iron Loss

The paper deals with rotor resistance identification of induction motor considering core loss. The rotor resistance can not be measured directly and easily varies with the increasing temperature. The problem of its identification bases on equivalent circuit. In the equivalent circuit, the equivalent resistance of core loss is in parallel with mutual inductance of induction motor in two-phase stationary frame. Based on the model, an algorithm of auto-tuning rotor resistance identification has been deduced in steady state. Then a case of induction motor considering iron loss has been simulated for rotor resistance identification. In steady-state operation, the auto-tuning identified result smoothly matches actual value. In dynamic-state operation, the identification algorithm is inaccuracy. Due to the large thermal time constant and temporary dynamic state, some measures have been taken to hold the identified output result. The rotor resistance identification is valid and feasible.