DSP-controlled Direct Torque Control of Induction Machines Based on Modified Integrator

In high performance variable speed drives, such as the vector control, in order to keep the synchronism between the rotor and the flux, a sensor is always required to detect the position of the rotor. However, the utilization of sensor will increase the cost and deteriorate the stability, or even be forbidden in some applications. In this paper, the direct torque control (DTC) scheme is employed to control the induction motor. A modified integrator is developed to solve some problems produced due to the pure integrator. The performance of this integrator is studied and verified through simulation and experiment. Finally, the experimental investigation on a DSP-based drive system is presented. It´s validated that the motor with the proposed control strategy has satisfactory starting and operating performance.