This paper proposes a nonlinear controller for brushless doubly fed induction motor (BDFIM) drives on the basis of input—output feedback linearization (IOFL). In the proposed control approach, firstly, the maximum torque per inverter ampere (MTPIA) control strategy is considered by applying a fifth order model for BDFIM. By realizing the MTPIA, the control winding current magnitude is minimized under the constraint of constant torque. To share the current between power and control windings fairly and minimizing the total stator currents magnitude for a given torque, the MTPIA idea should be extended. Since, the power winding of BDFIM in not controllable, obtaining this purpose is a challenge. Therefore, to solve this problem, the maximum torque per total ampere (MTPTA) strategy is introduced for BDFIM drives. In addition, using the fifth order model of BDFIM, a nonlinear controller is developed based on IOFL which is capable to force the deviation from realization criterion of both proposed strategies to zero while the torque is controlled with high accuracy. The overall stability of the proposed controller is proven using Lyapunov control theory. The validity of the proposed approach is finally verified by simulation and experimental results.

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