Torque ripple reduction and fast torque control in DTC of induction machine using overlapping triangular-based constant frequency torque controller

Constant frequency torque controller-based direct torque control (CFTC-DTC) becomes an attractive control scheme as it offers constant switching frequency and reduces torque ripple while retaining the simplicity of DTC. Nevertheless, when compared with the classical DTC algorithm, CFTC-DTC suffers from the limitation of torque bandwidth because of the time requirement for triangular waveform generation. In this paper, DTC with an overlapping triangular based constant frequency torque controller (OTCFTC) is proposed. The mean aspect of the proposed technique is that it utilizes the same execution time to generate two overlapping triangular waveforms rather than one. In this way, the torque will have higher bandwidth to achieve less torque ripples and better torque dynamic. The simulation results are presented to substantiate the effectiveness of the proposed motor drive.