FOC-Based Sensorless Control for Torque Ripple Reduction in PMSM Drives Using STM32 Platform

This paper presents the design and implementation of a Field Orientation Control (FOC) based speed controller for a three-phase Permanent Magnet Synchronous Motor (PMSM), aiming to reduce rotor torque ripple effectively. The system is developed using an STM32F401RE microcontroller along with a Simonk 30A Electronic Speed Controller (ESC), ACS712 current sensor, and TCRT IR sensor for effective motor control. The use of the FOC algorithm results in smoother operation and improves efficiency. The implementation is done on the STM32 Motor Control Workbench and validated through hardware testing. The initial torque is observed to be 0.15 N · m at 2500rpm, and the peak torque is 0.45 N · m at 9000rpm, respectively. The torque becomes constant at 0.05 N · m beyond 16000rpm. Whereas for a similar setup using a six-step computation strategy, the torque generated initially at 2500rpm is 0.6 N · m, and the peak torque is 1.3 N · m at 9000rpm. The obtained results are validated according to the IEEE standards (IEEE 181-2011) for safe operation of the motor within the prescribed operating region of torque ripples. The torque ripples using the FOC algorithm are observed to be 6.6% and six-step commutation is 20%. Therefore, comparative analysis with traditional six-step commutation reveals that the proposed FOC strategy significantly reduces torque ripple, improves speed stability, and enhances the dynamic response of the motor. This makes it a suitable solution for high-performance applications such as robotics, EVs, and industrial automation.