A constrained optimization based torque control approach for inverter-fed induction motors

In this paper, a constrained optimization based approach is proposed for the control of inverter-fed induction motors. This approach has many distinguished features: the measurements are motor velocity and currents, the tracking of torque command is optimized, the switching signal of inverter is determined directly from the feedback signals. This approach may be viewed as an improved SVM (space vector modulation) method, but instead of the tracking of a voltage command we track the current and flux commands directly which is equivalent to the tracking of torque and flux commands. This method greatly simplifies the control structure and computation complexity, and the optimality is guaranteed even in the overmodulation region.