Robust position control of synchronous reluctance motor drives using linear variable structure and adaptive input-output feedback linearization approaches

A nonlinear robust position tracking controller is presented for a three-phase synchronous reluctance motor (SynRM) considering the control strategy of maximum torque control (MTC) related to this motor. Ignoring the motor iron losses, the proposed controller is designed based on combination of linear variable structure and adaptive input-output feedback linearization (AIOFL) techniques. At first step, a sliding mode-plus-PI controller is designed for prediction of the stator current reference signal. The proposed position controller is fast response and robust against mechanical parameter uncertainties and load torque disturbance. At Second step, the proposed sliding mode based AIOFL controller estimates the unknown electrical uncertainties without using sign(.) or sat(.) function. Hence, it reduces chattering or steady state error phenomenon. Finally, the effectiveness and feasibility of the proposed control approach is demonstrated by computer simulation. The results obtained confirm that the desired position reference command is perfectly tracked in spite of motor parameter uncertainties and load torque disturbance.