Direct torque control of induction machines with constant switching frequency and improved stator flux estimation

Direct torque control (DTC) of induction machines is known to have a simple control structure yet has comparable performance to that of the field oriented control (FOC). To maintain this simple control structure while at the same time improving the performance of the DTC drive in terms of switching frequency and stator flux estimation, two simple techniques are proposed. The effectiveness of the proposed techniques are verified experimentally which is centered around a TMS320C31 digital signal processor.