The Research On Brushless DC Motor Torque Ripple And Suppression Methods

The brushless DC motor is different from the traditional DC motor, it is to use electronic commutation technology replaces the traditional DC motor mechanical commutation, it not only inherites the mechanical brush DC motor commutation good performance, but also makes the motor starting and speed regulation characteristic more excellent, it mainly manifested in the good control performance, wide speed range, starting torque, smooth operation, high efficiency, and it can solve the result of the operation in the process of mechanical brush friction sparks, more suitable for application in some special occasions. Therefore, it is widely used in the computer peripherals, household electrical appliances, servo drive control, aerospace, medical equipment and other fields. The brushless DC motor torque ripple based on assisted expectoration instrument is studied in this paper.First of all, according to the working principle of the brushless DC motor, the mathematical model is deduced in the paper, research on the assisted expectoration instrument works and determine the matching brushless DC motor, design its mechanical structure size, connecting method, the parameters and external control signal of the drive. Secondly, the causes of the brushless DC motor commutation torque ripple and its inhibition method is analyzed, studies on the effect of PWM modulation on the electromagnetic the motor torque ripple and its control strategy, and gives the compensation control of PWM-ON-PWM modulation method of the non-commutation torque ripple. The fuzzy adaptive PID control strategy is introduced based on the traditional digital PID control strategy. Using MATLAB/Simulink software development platform, the paper completes the brushless DC motor double closed loop control system simulation model, simulates the brushless DC motor with the actual parameters of the assisted expectoration instrument. The simulation results show that the fuzzy adaptive PID control hold the on-line adaptive regulating ability, good dynamic performance, the stronger robustness and anti-interference ability, it can effectively suppress the Brushless DC motor torque ripple. Finally, the paper has carried on the summary to the full text and discusses the future work.