Steady-state and transient performance evaluation of a DTC scheme in the low speed range

In this paper, a direct flux and torque control scheme for industrial application is analyzed in order to emphasis the drive performance at standstill and in the low speed range. The control strategy utilizes the torque and rotor flux commands to determine the reference value of the stator flux. In order to improve the low speed performance a closed loop estimator is employed to evaluate the rotor flux. The validity of the control scheme is verified by simulations and experimental tests of an induction motor drive system.