Performance analysis of sensorless SM-DTC using MRAS-sliding mode observer for induction motor fed by two different topologies of inverter

The installation studied in this work consists on applying the direct torque control (DTC) based on the sliding mode (SM) to an induction motor which will be supplied once by a conventional two-level inverter and a second time by an NPC three-level inverter, with an estimator based on the model reference adaptive system (MRAS) combined with the sliding mode method. The application of the sliding mode control strategy acquires great robustness to the system, whereas the adoption of the NPC three-level inverter considerably reduces ripples while improving waveforms. Finally, the conjunction of the MRAS estimator with the SM accentuates the system performance and reduces the sensibility to the various disturbances. A comparison study with the same control and observing strategies of the motor fed by the classical two-level inverter and the NPC three-level inverter through MATLAB/SIMULINK software is presented.