Preventing Magnetic Saturation and Reducing Torque Ripples in Induction Motors Using an Improved Field-Oriented Control System Based on Sliding Mode Technology

Abstract Field-oriented control (FOC) is a widely used strategy that allows independent control of torque and flux in induction motor systems. By applying Park transforms to convert three-phase signals into a dq reference frame, accurate motor speed regulation is achieved while maintaining constant flux for optimal performance and efficiency. Traditional field-oriented control (TFOC) assumes constant rotor resistance; however, variations in this parameter can degrade control accuracy and stability. This research presents an enhanced field-oriented control (EFOC) system that effectively compensates for rotor resistance variations by directly regulating the flux vector in the dq frame, ensuring flux stability and reducing reactive power consumption. Additionally, sliding mode control (SMC) is applied to the outer and inner loops to enhance system robustness, minimise torque ripples and improve dynamic response. Simulation results confirm that the proposed EFOC maintains the flux at its nominal value under resistance changes, achieving a 20% reduction in reactive power, approximately 6% improvement in power factor and reducing torque ripples from 13 N · m −1 to 0.3 N · m −1 , demonstrating superior performance compared with conventional proportional-integral (PI)-based FOC systems.