异步电动机低转矩脉动直接转矩控制研究

Research on Direct Torque Control of Induction Motor with Low Torque Ripple

针对异步电动机直接转矩控制中存在的转矩脉动问题,提出了一种基于多扇区的转矩脉动抑制策略。通过减小磁通在旋转过程中的空间角度,使磁通与电压矢量间的夹角趋向于连续,从而降低电压矢量步进式切换造成的脉振转矩,同时提取电压空间中的主矢量,以对称地改变定子磁通幅值并消除电流畸变引起的转矩脉动。仿真结果表明,该方案能有效降低异步电动机低速运行时的转矩脉动,提高直接转矩控制系统的响应特性。

Focusing on the problem of torque ripple in direct torque control of induction motor, a torque ripple restraint method based on multi-segment was proposed. Through reducing the space angle of the spinning flux, the angle between flux and voltage vector included tends to continuous, thus the torque vibration caused by step cut of voltage vector is reduced. Meanwhile the voltage main vectors, which are employed to change stator flux amplitude symmetrically, eliminates torque ripple due to current distortion. Simulation results show that this method can reduce torque ripple of induction motors at a low speed and improve repose behavior for direct torque control systems.