A Three-Level Inverter Based Direct Torque Control Scheme With Reduced Common-Mode Voltage For Induction Motor Drive

A Direct Torque Control Scheme with reduced common mode voltage for an Induction Motor drive fed by a three-level inverter is proposed in this paper. This scheme serves to reduce the common-mode voltage, by optimally selecting voltage space vectors in such a way that the common-mode voltage magnitude is either $\displaystyle \frac {V_{DC}}{6}$ or 0 where VDC is the maximum magnitude of the realizable voltage space vector. To validate the proposed scheme extensive simulations are carried out on MATLAB-Simulink platform. The proposed DTC scheme is experimentally verified on an induction motor fed by a three-Ievel inverter using TMS320F28335 digital signal processor for control algorithm implementation.