Bus clamped Space Vector Pulse Width Modulated Direct Torque Control of Induction Motor

Quick torque response, robustness and simple control scheme of classical direct torque control (DTC) make them a suitable choice for electric drive applications. However, in classical DTC, the switching frequency is not constant and there is considerable amount of torque ripple unless the switching frequency is very high. To improve the performance, classical DTC with space vector modulation (DTC-SVPWM) is sometimes used to reduce the torque ripple and make the drive operate at constant switching frequency albeit increased complexity. This paper proposes a new carrier based DTC scheme with bus clamped space vector modulation (DTC-BCSVPWM). The advantage of using carrier based SVPWM is to minimise the computational burden whereas bus clamping is employed to reduce switching losses. The effectiveness of the proposed scheme is illustrated using MATLAB simulations and hardware results.