含零矢量作用的永磁同步电机直接转矩控制研究

通过对永磁同步电机直接转矩控制机理的分析,指出了永磁同步电机与异步电机在实施直接转矩控制上的某些差异,其中零电压矢量的作用有所不同.由于永磁同步电机控制变量中没有转差的概念,电磁转矩变化受控于功角与功角的增量,而零电压矢量对功角增量的作用很弱,因此一般从转矩的动态控制效果认为,零矢量不适合在永磁同步电机直接转矩控制中应用.文章对此作出了修正,从理论和实验角度都证明,零矢量可以参与永磁同步电机转矩的直接控制,在有效抑制转矩和磁链脉动及提高系统性能上有独特的作用.

Studies on Null Vector in a Direct Torque Control of Permasyn Motor

The paper gives an analysis of the control mechanism for direct torque control mechanism of a permasyn motor,which points out some differences between the permasyn motor and asynchronous motor in the implementation of direct torque control,especially the differences in the function of null-voltage-vector.Owing to the absence of the slip in the permasyn motor control variable,the electromagnetic torque is controlled by the incremental quantity of the torque angles while the effect of null vector on torque angle increment is very weak.Therefore,a general point of view is that the null vector is not suitable for direct torque control in the permasyn motor.This paper modifies this viewpoint and verifies both from theory and experiment that the null vector can directly control the torque of permasyn motor and possesses unique function in effectively restraining torque and flux ripples and improving the performances of the system.