基于DSP的无刷直流电机新型转矩脉动抑制策略

New Torque Ripple Suppression Strategy for Brushless DC Motor Based on DSP

摘要:

无刷直流电机在换相时,非换相相绕组电流会产生脉动,绕组电流的脉动会引起输出转矩的脉动；研究无刷直流电机换相转矩脉动问题,是为了获得无刷直流电机更优的转矩输出特性,提高控制系统的稳定性和控制精度；通过分析换相转矩脉动的成因,在传统PWM_ON_PWM三相全桥调制方式的基础上,加入新型相电流预测控制算法,调节关断相和开通相电流下降和上升的速率,从而抑制相电流的脉动；利用DSP实现算法,验证了算法的可行性,通过实验数据和波形的对比分析,PWM_ON_PWM调制策略与电流预测算法相结合的控制算法可以有效抑制换相引起的转矩脉动。

Abstract:

The current of the non commutation phase will ripple when brushless DC motor commutates. The ripple of the phase current must cause the ripple of the torque.In order to obtain better brushless DC motor torque output characteristics, research of torque ripple for brushless DC motor is necessary.That can improve the control stability and precision of the system. Through the analysis of the reason of the torque ripple, joining the current predictive control algorithm on the basis of traditional PWM_ON_PWM modulation regulate current increase and decrease rate of off phase and open phase.Which can suppress the phase current ripple.Finally using the DSP implement such algorithm and verify the feasibility of the algorithm. Combining PWM_ON_PWM modulation strategywith the current prediction algorithm can effectively suppress commutation torque ripple by comparing the experimental data and waveform analysis.