Research On Suppression Of Commutation Torque Ripple Of BLDC Motor

Propulsion system is an important part of underwater vehicle.The propulsion system can ensure the efficient operation of the underwater vehicle,and the propulsion system of the underwater vehicle is of great significance to the protection of national maritime rights and the development of marine resources.The traditional underwater vehicle propulsion system adopts the thermodynamic propulsion method.The problems of the traditional underwater vehicle propulsion system are large noise,complicated structure,high maintenance cost,and poor concealment.The use of electric propulsion method can effectively make up for the above disadvantages.In this study,in order to solve the torque ripple of the brushless DC motor and to achieve the control of the dual motors,an algorithm to improve the control performance of the brushless DC motor was designed,and carried out experiments and simulations.A control method for suppressing torque ripple of BLDC motor is studied.The PWM-ON-PWM control mode is selected to achieve the suppression of non-conducting phase ripple current.Under this control mode,the cause of commutation torque ripple is further studied.During the commutation process,the off-phase adopts the PWM control method,and the on-phase and non-commutation phase adopt the constant-pass control method,which realizes the suppression of the commutation torque ripple.The effectiveness of the torque ripple suppression algorithm is verified by simulation and experiment.The torque ripple suppression algorithm depends on the motor parameters,which are susceptible to the operating environment.Therefore,the torque ripple suppression algorithm needs to be further improved.The principle of recursive least squares algorithm with forgetting factor and Kalman filter algorithm are analyzed,and an online parameter identification model of brushless DC motor based on these two algorithms is designed.By combining the parameter online identification data with the torque ripple suppression algorithm,a perfect torque ripple suppression algorithm is obtained.The performance of these two online parameter identification algorithms was compared through simulation.Finally,the recursive least squares algorithm with forgetting factor was selected to realize the online identification of motor parameters.An overall control scheme for dual motors is proposed.Considering that the structure of the inner shaft motor and the outer shaft motor are exactly the same,a completely consistent control algorithm is adopted for the inner shaft motor and the outer shaft motor.Through the timer polling control of DSP,the two motors achi eve the same speed and opposite directions.Finally,the consistency of the speed and the running performance with load of the inner shaft motor and the outer shaft motor were verified through experiments.