Research On Torque Ripple Suppression Technique Of Brushless DC Motor

The brushless DC motor(BLDCM) is a DC motor using electronic commutation instead of the mechanical commutation, so it has excellent characteristics of DC motor, such as good start and timing performance, and on the other hand it overcomes the friction disadvantages of ordinary DC motor radically with its simple brushless structure. It has been extensively used in many industrial domains, such as aviations, robots, digital machine tools, and in medical or home appliances. But the BLDCM has the disadvantages of torque pulsation, which is in the way of achieving accurate position and speed of higher performance. The objective of this dissertation is to study the control technology to minimize the torque pulsation of BLDCM.Firstly, introduce the working principle and conducting mode of Brushless DC Motor (BLDCM), establish the dual-loop control of the MATLAB simulation through on the basis of mathematical model. Secondly, analysis the reasons and suppressions of torque ripple, the influence of commutation process, converter process, PWM control and commutation dead zone on the commutation torque ripple. At the same time, give the method of calculating the commutation time and current. Then, research the strategy of PWM modulation on Brushless DC Motor, introduce its techniques in BLDCM, detailed analysis the basic principles of PWM, as well as the application of different PWM modes which aims to decrease the commutation torque ripple, certificated the conclusion by simulation. Finally, proposed the hardware and software design options of BLDCM based on the TMS320LF2407ADSP.