The point of view of motor and control, the paper expounds all kinds of cause of dcmotor’s ripple torque. especially ,analyzes the cause of commutaio torque ripple. mathematical model is presented based on the operating principle of BLDCM, which is analyzed indetail. This paper introduces software Matlab/Simulink and how to use it. Simulink model of three-phase BLDCM is set up and performed. The control system is virtually a dual closed-loop system with current controlleras inner loop and speed controlleras outer loop. speed controller adopts P regulator and current controller adopts PI regultor. We estimate rotation position through brushless domotor's emf.The simulation results are discussed, which are consistent with the theoretical analyse. thus the model is verified through simulation.
