The research of different pulse width modulation strategies used in control moment gyro gimbal motor

Regarding the brushless direct current motor(BLDC) used in control moment gyro (CMG) gimbal, different pulse width modulation (PWM) strategies of the drive circuit have different influences on the torque ripple of the system. An analysis is made on the different PWM strategies in the view of two aspects, including the commutation torque ripple and the non commutation torque pulsation, and a conclusion is given that the best PWM strategy for high precision control requirements is the PWM_ON_PWM strategy. This strategy can be implemented using the conventional three way Hall signals in combination with the field programmable gate array(FPGA) hardware programming, and it is verified through experiments, furthermore the torque ripple is decreased by 10% with respect to the other strategies.