An improved control strategy for induction motor under unbalanced voltage source with torque loop

As one of the most commonly used electric motors, induction motor (IM) frequently encounters unbalanced voltage supply when being connected with power system supplies. The unbalanced voltage can cause issues such as unbalanced motor current, torque ripples, and motor speed pulsations, reducing both efficiency and lifespan of motors. This paper addresses these issues by proposing a compensatory torque loop strategy. The effectiveness of the proposed method is evaluated through a field-circuit-control co-simulation of motors under various operating scenarios. The results demonstrate that the proposed strategy can significantly improve key performance metrics, achieving a reduction in torque ripple of up to 66 %, and nearly 50 % even under more challenging conditions—all without the introduction of additional compensation hardware.