A switching adaptive controller for the reduction of commutation torque ripple in BLDCM drives

A switching adaptive controller with commutation delay compensation is proposed to control the torque output and to reduce commutation torque ripple in uncertain brushless DC motor (BLDCM) drives. After deriving the error dynamics, the conduction and commutation periods of the drive is taken into account separately, and two different controllers are designed for each operation region of the current loop of BLDCM drives. All the system constants in the mathematical model of the drive are considered uncertain, and adaptation rules are derived for these unknown parameters. The stability of the closed-loop system is shown by a common Lyapunov function, and the convergence of the current error to zero is proved as well. Finally, a commutation delay compensation scheme is introduced and added to the controller structure. Various numerical simulations are performed for different working conditions to test the viability of the proposed controller.