Comparison between Direct Torque Control based on Space Vector Modulation with Conventional Direct Torque Control Technique for Speed Control of Three-phase Induction Motor

This paper represents comparative performance analysis between switching table based direct torque control (ST-DTC) and direct torque control with space vector modulation (DTC-SVM) for different torque and speed pattern for three-phase induction motor. One of the modern control methods used to regulate AC motor speed is DTC. Basically, DTC is control scheme which directly control the stator flux and torque. Conventional DTC uses switching table for selection of voltage vector. In conventional DTC there is some disadvantages like high torque ripple, machine vibration and noise which are overcome in DTC-SVM technique. In DTC-SVM technique space vector modulation used to improve efficiency of motor by selecting the appropriate voltage vector. Two-level inverter is used for both DTC and DTC-SVM technique. Moreover, in DTCSVM technique have many more advantages like low ripple torque in transient state, lower current distortion, lower switching losses etc. Both the proposed techniques are implemented using MATLAB/ SIMULINK software. DTC-SVM technique provide better results as compare to ST-DTC technique.