A Modified Direct Torque Control Approach With Carrier‐Based Torque and Flux Controllers for Improvement of Steady‐State Performance of Five‐Phase Induction Motor

ABSTRACT The classical direct torque control (DTC) of five‐phase induction motors is a simple control technique and exhibits fast dynamics; however, it suffers from significant drawbacks like high flux ripple, torque ripple, current harmonic distortion, and variable switching frequencies. Several modified DTC control strategies have been proposed to address these issues by employing multiple lookup tables or multilevel hysteresis torque controllers, which increase the complexity of the system. In this paper, a novel approach is proposed that replaces the classical hysteresis torque and flux controllers with a triangular‐carrier‐based three‐level constant switching torque (CST) controller and a two‐level constant switching flux (CSF) controller. This approach, known as constant switching torque‐flux controllers‐based DTC (CSTF‐DTC), significantly enhances the steady‐state performance of the five‐phase induction motor by mitigating flux ripple, torque ripple, and current harmonic distortion without compromising dynamic behavior and without altering the generality of the classical DTC method for simplicity. The proposed CSTF‐DTC scheme also effectively eliminates harmonic plane components using virtual voltage vectors. Experimental results on a two‐level inverter‐fed five‐phase induction motor validate the superior performance of the proposed method over existing DTC techniques for a wide range of operating conditions and dynamics.