Performance Enhancement of Induction Motor Based on Three-Level T-Type Inverter Using DTC-SVM

Abstract

Induction motors (IM) that are driven using the conventional direct torque control algorithm (DTC) suffer from vital drawbacks which are high ripples in the torque and flux. These ripples result due to the use of a look-up table and hysteresis comparators which causes variable switching frequency. Moreover, the use of a traditional two-level inverter leads to the production of low-quality voltage and current. The work presented in this paper proposed a modified control system to overcome these drawbacks. The proposed control system is based on the use of the space vector modulation-based DTC algorithm (DTC-SVM) for driving three-phase IM via a three-level T-Type inverter. The conventional DTC-SVM algorithm has been modified to match the work of the proposed inverter. The modification process was based on the mapping of the standard DTC-SVM algorithm in the space vector of the three-level inverter. The conventional and the modified control systems are implemented using MATLAB/Simulink package. The comparison of the standard and the modified DTC-SVM has been performed by simulation. Simulation results showed the superiority of the proposed algorithm in terms of reducing ripple in torque and flux and improving the quality of current and voltage supplied to the motor.