A novel Direct Torque Control for Doubly Fed Induction Machine based on Indirect Matrix Converter

This paper presents a novel Direct Torque Control (DTC) of Doubly-Fed Induction Machine (DFIM) based on Indirect Matrix Converter (IMC). The matrix converter allows many advantages compared to the conventional voltage or current source inverters. Functionally the IMC is very similar to the Direct Matrix Converter (DMC) but it has separate line and load bridges. Indirect matrix converter has no electrolytic capacitors in the DC link, which results that volume and size of converter reduced and increased longevity. The indirect modulation technique used in indirect matrix converter is able to provide practically sinusoidal waveforms of the input and output currents with venial harmonics amplitude. In the inverter stage, the classical DTC method is employed. In the rectifier stage, in order to reduce losses caused by circuit snubber the rectifier four-step commutation method is employed. The simulation results of DTC system based on IMC confirms its effectiveness and accuracy.