A novel DTC-SVM approach for two parallel-connected induction motors fed by matrix converter

AC machines fed by a single inverter are widely used in industries such as railroad electrification systems where speed synchronization does not have to be exact. The low cost and volume and the small number of power electronic components are attractive aspects of single-inverter multi-motor systems. This paper proposes a novel approach to controlling the speed and torque of two induction motors connected in parallel and fed by a matrix converter under unbalanced load condition. This single-inverter dual-motor (SIDM) drive uses average and differential values of speed and torque together with stator and rotor flux parameters based on the flux dead-beat scheme. An advantage of the proposed approach, compared with the conventional direct torque control (DTC) method, is that it eliminates the lookup table and lowers the torque and current ripple through the use of the PI controller instead of hysteresis blocks. Combining DTC and space vector modulation (SVM) with a matrix converter (MC) and achieving the unit input power factor are other advantages of the present study. The main purpose of this study was to propose a new drive system with an MC for two parallel-connected induction motors using the DTC method and SVM consisting of a flux dead-beat scheme.