Research On Key Technologies Of Suppression Torque Ripple For Brushless DC Motor

Since the advent of the motor become the main power output device,after many years of development,it has extensively used in all aspects of daily production and everyday life.Different applications and different control precision requirements put forward different requirements on the performance of the motor.At present,the motor industry is mainly divided into three major categories of motors,that is,DC motors,synchronous motors and asynchronous motors.Among them,the DC motor`s starting characteristics,wide speed range,make it widely used in electric drive system.Sensorless BLDCM has many advantages such as simple control algorithm,large motor power density,high efficiency,nice dynamic performance and good environment adaptability.Although position sensorless control technology has made good progress from its introduction to now,the industry's workers have never stopped moving forward in seeking more reliable,stable and precise g sensorless control technology in commutation.At the same time,the torque ripple suppression of the square wave brushless square wave brushless DC motor is still the bottleneck of the brushless DC motor in the application of high torque performance,and based on the control of the sensorless control statagy,the commutation torque Pulse suppression is even more challenging.After reading a lot of literature about brushless DC motor,this paper briefly illustrates the structure and operating mechanism of brushless DC motor,and analyzes the principle of double closed-loop control of classic brushless DC motor.Then through light upon various reasons leads to the commutation electromagnetic torque ripple.Followed by the analysis of motor commutation process match the equivalent circuit topology,find out the physical parameters related to the commutation torque,then put forward a profound expression of the current phase commutation torque ripple causes.Based on this,several typical commutation torque ripple suppression methods are analyzed.after hving a great idea of thses control stratagem,a commutation torque ripple control strategy based on PWM chopper control is proposed.Then the dual closed-loop simulation model of the sensorless brushless DC motor and the torque ripple suppression model based on the PWM chopper method are built in the Matlab / Simulink module to verify the correctness of the back-EMF zero-crossing detection commutation.The square wave Brushless DC commutation torque ripple indeed exists the theoretical correctness get verified.The simulation results show that the PWM chopper torque ripple suppression method of dual current regulator can restrain the commutation torque ripple,and the effect is slightly better than the high speed phase while it works in the low speed stage.All of these verify the effectiveness of the proposed theory.Finally,according to the idea of this paper,the hardware system plan and software implementation strategy of hardware physics experiment platform are drawn up.Combined with the actual production and everyday life,it indicates the direction of further research work in the end.