A nonlinear control scheme is proposed for real-time tracking of maximum torque per Ampere trajectory of the surface mounted brushless DC motor with non-sinusoidal back-EMF. The strategy employs the Lagrange\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\'s Theorem to obtain the optimum stator current, at which both torque ripple and corresponding current magnitude become minimized. A new criterion is introduced in such a way that, when forced to zero, guarantees MTPA realization. The input-output feedback linearization (IOFL) control scheme is employed to improve tracking of the applied optimum currents. In the suggested approach, the magnitude of the stator current vector is minimized effectively in each instant. The performance of the control system is validated through experimental results.

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