Reserch On Vibration Torque Inhibit Of Permanent Magnet Brushless DC Motor

Permanent-magnet brushless DC(PMBLDC)motors are widely used in various fields due to the excellent performance such as good speed control performance,high power density,and low noise.With the higher requirements on the motor performance,the pulsating torque problem of the PMBLDC motors is concerned.Therefore,the suppression of the pulsating torque of the PMBLDC motors has become the study of the industry and the majority of scholars.There are many factors that produce a pulsating torque in the PMBLDC motors.The main pulsating torque component is generated by the current commutation process.For the suppression of this pulsating torque,the current research methods and ideas are achieved through the optimization of control strategies.Many scholars have proposed some effective methods to reduce the pulsating torque,but many methods still remain at the theoretical simulation stage.Through the actual measurement of the pulsating torque of a typical PMBLDC motor,it has been found that the pulsating torque is still evident and still serious.In view of this situation,this paper proposes a method to suppress the pulsating torque of PMBLDC motor based on the principle of peak-valley complementarity.Starting from the study of the motor body,two PMBLDC motors generates two pulsating torques with the same amplitude and opposite phases,which are used to achieve the suppression of pulsating torque through peak-valley complementarity;This study presents a model of a PMBLDC motor with low pulsating torque based on this principle,and carries out related theoretical and experimental research.Firstly,The pulsating torque theory simulation study was carried out,and the commutating torque characteristics of the motor were experimentally studied.It was verified that the pulsating torque of the PMBLDC motor actually existed and the most important component of the pulsating torque was caused by current commutation.Secondly,an experiment platform was built based on the method of peak-valley complementary suppression of pulsating torque and the model of PMBLDC motor based on this principle.it is found that the commutating pulsating torque is greatly suppressed by measuring and analyzing the pulsating torque on the output shaft of a PMBLDC motor with low pulsating torque,thus verifying the correctness and feasibility of the method.Then,aiming at the asymmetric phenomenon of the pulsating torque waveform in the PMBLDC motor and the effect of the peak-valley complementarity suppression effect,a method to improve the symmetry of the pulsating torque waveform is proposed.Through experiments,it is verified that the symmetry of the output pulse torque waveform of the PMBLDC motor is effectively improved by adopting the improved method,the output torque of the motor is further significantly suppressed,and the suppression effect of the pulsating torque of the PMBLDC motor is improved.