Direct torque control of induction machine under square wave conditions

The authors of this paper present direct torque control (DTC) under square wave conditions. After describing the principles of the control system at high speed, they propose a control structure under square wave operation to optimize power and losses in the inverter and the machine. A transition method allowing transient problems between the two control modes to be minimized, is presented. Finally, they estimate the structure of the proposal by simulating good results on torque control obtained during square wave passage and up to very high machine speeds. They validate the control system at high speed by DSP implementation and experimental results.