A sensor-less adaptive rotor parameter estimation method for three phase induction motor

Accurate online parameter estimation is very important for inverter driven induction motor drives. Among the motor parameters the rotor is more prone to high percentage of parameter change. An adaptive rotor parameter estimation method is proposed including a detailed motor model. When the motor reaches steady state under constant load the stator current is monitored. The stator current of the motor is compared with the stator current of the model and the error is used recurrently to reestablish the model. The adaptation process stops when a threshold of the error value is reached. The estimated rotor resistance is compared with the original value. The response of the model with different change of parameters is also analyzed.