Torque control of induction motor drives based on One-Cycle Control method

The first work on direct torque control (DTC) of induction motor (IM) was based on hysteresis controllers and Switching Tables. Although it has the advantage of simplicity, it has a few drawbacks such as current, torque and flux distortions, and variable frequency operation. Posterior DTC works have solved most of these problems, but with added complexity to the control algorithm. This paper presents a new flux and torque controllers, for DTC of IM drives, based on One Cycle Control (OCC). The proposed control method (DTC-OCC) is capable of solving most of the original problems of DTC such as operation at fixed frequency with reduced ripple on flux, torque and current, while recovering at the same time, the simplicity of the DTC algorithm. As OCC has been considered as a generalized PWM modulator, the theoretical foundations of the new method are provided from both PWM and OCC approaches. Simulation and DSP-based experimental results show good performance of the proposed control and confirm the theoretical analysis and assumptions.