基于占空比调制的无刷双馈电机转矩脉动最小化控制研究

RESEARCH ON TORQUE RIPPLE MINIMUM OF BRUSHLESS DOUBLY-FED MACHINES BASED ON DUTY RATIO MODULATION

针对无刷双馈电机采用传统直接转矩控制方法存在着转矩和磁链脉动大、开关频率不固定等问题,在分析传统直接转矩控制产生脉动原因的基础上,提出一种基于占空比调制的脉动最小化直接转矩控制策略,根据无刷双馈电机的状态方程,结合预测控制思想,根据当前电流、转矩和磁链预测下一时刻的转矩和磁链,采用一个控制周期内转矩脉动最小化原则计算出非零电压矢量作用的时间,从而减小转矩脉动。实验验证表明,该控制方法在保持传统直接转矩控制优点的基础上,能有效减小转矩脉动,改善直接转矩控制的性能。

To deal with the large torque ripple and inconstant switch frequency of the traditional direct torque control for Brushless Doubly-fed Machines （BDFM） control system, a torque ripple minimization of the direct torque control for BDFM with optimal duty ratio control strategy was proposed. In the proposed strategy, according to state equation of BDFM and the idea of predictive control, the torque and flux of next sampling time was predicted based on present current, voltage, torque and flux and calculate the duration time of active voltage vector with the error of torque and flux in the next control period. Experimental results showed that the proposed strategy has the advantages of traditional DTC and reduces torque and flux ripple effectively which improve the performance of traditional DTC.