In this paper, a nonlinear controller capable of high dynamic torque regulation is introduced for Synchronous Reluctance Motor (SynRM) drive on the basis of input-output feedback linearization considering the different strategies related to this motor. The control strategies considered are: maximum torque per Ampere (MTPA), minimum KVA rating for the inverter and efficiency-optimized control. The proposed nonlinear controller is capable of regulating the motor torque by selecting the product of d and q axes torque currents as one of the output variables. As a result, the nonlinear and crosscoupling aspects between the d and q axes torque currents and the terminal currents can be eliminated. Hence, the linear torque-speed characteristics can be achieved. In addition, absolute implementation of strategies needs motor parameters with sufficient accuracy. The stator direct axis inductance (Ld) and iron loss resistance (Ri) are regarded and a PI estimator is presented to estimate the stator resistance variation. Finally, simulation and practical results are included throughout the paper to illustrate and verify the theoretical considerations.

Keywords