Torque estimation using rotor slots harmonics on a three-phase induction motor

This work presents a new approach in order to estimate torque in an induction motor which drives a load without ever interrupting its operation. Rotor slot harmonics, that are present in the stator current of an induction motor with squirrel cage rotor, are applied to estimate the torque. In particular, the speed is obtained with the rotor slot harmonics methodology and it is employed on the linearized torque-speed curve to obtain the torque. Some experiments with induction motors have been conducted. Torque and speed of the motors have been estimated. Finally, the error curves of the torque and speed have been shown.