This paper proposes a new modified direct torque control for induction machine fed by three phase indirect matrix converter. The goal is to improve the performance of the control to reach three levels NPC inverter performances (flux, torque and speed) and to reduce the low frequency harmonics of the input current. The input power factor is fixed to one. Both the inversion stage and the rectification stage are controlled symmetrically to perform the same table as three levels NPC inverter. This method is simulated in Matlab/Simulink software with 1.5 kW induction machine. The results obtained are compared to the classical DTC. This method gives good performance in torque and flux in both transient and permanent mode and also it reduces the total harmonic distortion (THD) of the input filtered current.

Keywords: Indirect matrix converter (IMC), Direct torque control (DTC), Induction machine, Three levels neutral point clamped (NPC) inverter