Abstract: In order to solve the problem of torque ripple during commutation of brushless DC motors, based on the analysis of the commutation process in a two-phase stationary coordinate system, a new method for suppressing torque ripple injected with a specific voltage vector in the freewheeling phase is proposed. Firstly, the motor phase voltage is virtually divided into two parts and the scope of its action is reconstructed: one part is still applied across the windings to generate an imaginary equivalent current; the other part is used to "change" the back electromotive force (EMF), which is artificially compensated for precisely keeping the torque constant. Secondly, using the different effects of specific voltage vectors on torque, an injection vector amplitude adjustment strategy with a negative feedback link is constructed to ensure strong stability. This algorithm simplifies the analysis process while avoiding complicated duty cycle calculations. The simulation results show the correctness of the theoretical analysis. The experimental results verify the effectiveness of the new method in suppressing commutation torque ripple under high and low speed conditions.