Six‐switch inverter emulation based DTC strategy dedicated to three‐switch inverter‐fed induction motor drives

The aim of this paper is to propose a novel direct torque control (DTC) strategy for induction motor (IM) drives fed by three‐switch three‐phase inverter (TSTPI). The introduced strategy is based on the emulation of the operation of the conventional six‐switch three‐phase inverter (SSTPI).

The proposed strategy has been achieved thanks to suitable combinations of the six unbalanced voltage vectors intrinsically generated by the TSTPI, leading to the synthesis of the six balanced voltage vectors of the SSTPI. This approach has been adopted in the design of the vector selection table of the proposed DTC strategy which considers a subdivision of the Clarke plane into six sectors.

Simulation results have revealed that, thanks to the proposed DTC strategy, TSTPI fed IM drives exhibit interesting performance.

The results obtained by simulation should be validated by experiments.

The drawbacks associated with the application of unbalanced voltage vectors in previous DTC strategies dedicated to TSTPI have been eradicated thanks to the synthesis of six balanced voltage vectors using appropriate combinations of the TSTPI intrinsic ones.