Research On Commutation Torque Ripple And Sensorless Control Of Brushless DC Motor Used For Micro-flywheel

The micro flywheel control system is usually used in the satellite attitude control, which contains controller, driver circuit, driving motor and position sensor. Driving motor is the key component of micro flywheel control system. Brushless DC motor(BLDCM) has been more and more widely used, because of its advantages, such as good dynamic performance, long life, high power density and easy to control. This paper uses BLDCM as the driving motor. In recent years, small satellites have the higher and higher requirements of precision and reliability to the attitude control system, which means the requirements of BLDCM’s control performance and reliability is higher and higher.As the research object of this article, In this paper, firstly the composition of brushless dc motor control system is given, the simplified mathematical model of brushless DC motor is explained, its control principle is analyzed, and then the simulation model and experimental platform of the micro flywheel control system is built which is based on BLDCM.Secondly, in view of the micro flywheel based on BLDCM has the commutation torque ripple problem which affect the accuracy of attitude control system, the cause of commutation torque ripple is analyzed, a driver circuit based on ZETA converter for commutation torque ripple suppression is proposed, the control strategy of the driver circuit is studied, then its effectiveness is verified by simulation.The use of position sensor increases the size of the motor, at the same time because of the position sensor is easily affected by electromagnetic interference in space, which do’t match the volume and reliability requirements of attitude control system. This paper carried out deeply micro flywheel based on BLDCM with sensorless control research, using the rotor position detection method based on virtual neutral voltage to achieve the commutation signal extraction, and controlling the micro flywheel based on BLDCM by using the extraction of commutation signal. The experimental platform is built. The proposed method is verified by experiment comparision.