【摘要】 文中提出了一种新的基于占空比控制技术的异步电机直接转矩控制方案。传统直接转矩控制的缺点之一是输出转矩波动较大。占空比控制技术通过在每个采样周期中插入零电压矢量来减小转矩的波动。文中将合成电压矢量的思想引入到占空比控制技术中。推导得出了瞬时转矩改变量与合成电压矢量的关系,合成电压矢量与所选电压矢量及其占空比的关系。联立这两个条件,求解出了占空比的计算公式。最后,对所提出的直接转矩控制算法进行了仿真试验。仿真结果表明,该方案可以大大减小输出转矩的波动。更多还原

【Abstract】 A new direct torque control (DTC) strategy based on duty ratio control technique of induction motor drives is presented.One of the disadvantages of conventional direct torque control is high torque ripple.In duty ratio control technique,a zero voltage vector is applied in each sampling period to reduce the torque ripple.In this paper,the concept of synthesized voltage vector is introduced into duty ratio control technique.The relation between the synthesized voltage vector and instantaneous torque increment is derived.At the same time,the synthesized voltage vector can be expressed as selected voltage vector and its duty ratio.Combining the two conditions,the duty ratio can be calculated.Finally,the proposed strategy is verified by simulations.Simulation results show that a great reduction of torque ripple is achieved.更多还原