Robust Optimal Speed Tracking Control of a Current Sensorless Synchronous Reluctance Motor Drive using a New Sliding Mode Controller

This paper describes the robust optimal incremental motion control of a current  sensorless synchronous reluctance motor (SynRM), which can be specified by any desired speed profile. The control scheme is a combination of conventional linear quadratic (LQ) feedback control method and sliding mode control (SMC). A novel sliding switching surface is employed first, that makes the states of the SynRM follow the nominal trajectories (controlled by any type of nominal controller) when the motor parameter uncertainties and the disturbance load torque exist. The SM controller has no reaching phase and produces small SMC chattering. Then, using the above tracking controller, the well-known torque control schemes, maximum torque (MTC), constant current inductive axis control (CCIAC) and maximum power factor control (MPFC) related to the SynRM are examined below and above the base speed. Finally the validity of our proposed control scheme is verified by computer simulation results.