Continuous Fast Terminal Sliding Surface-Based Interrupt Free Operation of PMBLDCM Drive

This research proposes a sensorless Field Oriented Control (FOC) for Permanent Magnet Brushless DC Motor (PMBLDCM), employing a Continuous Fast Terminal (CFT) Sliding Mode Controller (SMC) which incorporates fault-tolerant operation for low cost electric vehicle. The approach presented here provides a robust quantitative design and execution of the speed controller, and integrates an estimation mechanism for total disturbances, including the effects of iron loss on electromagnetic torque. Initially, the rotor speed dynamics of the PMBLDCM drive system are studied, considering the lumped disruption which encapsulates interference, parametric complexities, and nonlinear dynamics. In this context, the applied Sliding Mode Observer (SMO) controller works to regulate real-time rotor speed and counteract lumped disruptions in rotor speed mechanics, thus ensuring fault-tolerant operation. The FOC scheme is then further enhanced to improve the generated torque while significantly minimizing ripple content. The proposed methodology eases the zero torque-pulsation restriction, thereby broadening the torque operation range. Furthermore, the technique can mitigate torque ripples throughout the complete torque operating spectrum for each reference value of torque. Ultimately, the introduction of the sliding mode control strategy increases the robustness of the PMBLDCM system, ensuring efficient and reliable operation under various disturbance conditions.