Reduction of Torque Ripples of Three-Phase Induction Motors Using Hybrid Vector Control Based on Space Vector Modulation

Three-phase induction motors as widely used electric drives in industry, automation, transportation and electric vehicles are mainly controlled by two conventional methods, vector control (VC) and direct torque control (DTC). The vector control method has a suitable steady state response, but in terms of dynamics and time to reach the steady state, it provides a relatively slower response. In contrast, the direct torque control method works almost the opposite way and provides a better dynamic response. Therefore, providing a control strategy that combines the advantages of the two mentioned methods as much as possible improves the driving performance of the induction motor. This paper presents a hybrid control method based on the optimal keying table to select the appropriate keying modes for the induction motor drive converter to improve the output dynamic response. To reduce current and torque ripples in different operational states, the space vector modulation technique has been used in the proposed drive system. The efficiency of the drive system presented with the hybrid control strategy has been compared with the conventional DTC and VC control methods, and the results illustrate a faster dynamic response of the proposed drive system with less steady-state ripples than the two conventional methods. Modeling and implementation of the proposed drive system have been performed in MATLAB/Simulink software.