Improvement of Efficiency of a Three-Phase Induction Motor Using Robust Control

Slip power recovery scheme is widely used for controlling the speed of a three-phase induction motor, but this method can also be used for increasing the efficiency of an induction motor. Here, a three-phase induction motor has been designed using vector-controlled induction motor drive and then the controlled strategy is introduced in this induction motor. The control strategy is based on feeding the slip power back to the rotor of a slip ring induction motor. The efficiency and torque of a three-phase induction motor depend upon the slip of the motor. This controller monitors the speed of the motor from no load to full load and takes the appropriate control action to maintain the speed of the motor. After implementation of this control strategy, it has been seen that the induction motor is trying to maintain the no load speed and as a result, the power output of the motor has been increased considerably.