The modeling and simulation of PWM mode for permanent magnet brushless DC motor

The paper builds the mathematical model of permanent magnet brushless DC motor(BLDCM), and adopts back electromotive force(EMF) of sensorless method to get rotor position information according to the requirements of the motor armature voltage signal with low harmonic requirements. Then the paper analyzes the impact that BLDCM adopts the PWM mode for the back EMF testing, at the same time builds the model and simulates in Pspice, and gives the motor armature voltage and current simulation waveforms for BLDCM in four different PWM mode. The simulation results show that the harmonic component of motor armature voltage is minimal in HPWM-LON modulation mode., so it is very important that selecting suitable PWM mode is stable operation for BLDCM. Therefore, it has very important role to select suitable PWM mode for stable operation of the BLDCM.