基于离散占空比控制的异步电机直接转矩控制

Direct Torque Control of Induction Motors Based on Discrete Duty Ratio Control Technology

传统直接转矩控制方法在启动和低速运行阶段存在转矩脉动较大的问题。本文基于异步电机数学模型推导出引起转矩脉动的主要因素,分析了基本电压矢量和零矢量对转矩的作用效果,提出了一种新的离散占空比控制技术。该技术对传统方法中的转矩调节器加以改进,并根据改进后的转矩调节器制定新的电压矢量表。仿真和实验结果表明所用方法有效抑制了转矩脉动,实现了更好的控制性能。

There exists a large torque ripple in the start-up and low speed operation stage of induction motors based on traditional direct torque control technology. On the basis of the mathematical model of induction motors, the paper deduces the main factors causing torque ripple, analyzes the effects of active vector and zero vector on torque and proposed a new discrete duty ratio control technique. This technique improves the torque regulator in the traditional method and develops a new voltage vector table according to the improved torque regulator. Simulation and experiment results demonstrate the method can largely decrease torque ripptes and achieve better torque control performance.