摘  要：为了解决三电平直接转矩控制中的矢量与矢量切换时过高的线电压跳变问题，对中点电压实现了实时控制。提出了一种改进型的虚拟合成矢量三电平直接转矩控制方法。同时，针对异步电动机直接转矩控制中对定子电阻和转子时间常数这些重要参数的依赖性，设计了一种基于模型参考自适应律（MRAS）的参数辨识器。该辨识器同时还可以观测定子磁链及转子速度，仿真结果证明提出的方法的有效性和可行性。
关键词：无速度传感器；三电平；虚拟合成矢量；直接转矩控制；感应电动机

Abstract: Animproved dummy synthesized vectors were given in the paper.This method was good at restraining the neutral-point ripple and eliminate the vector shift problem when sector changes.For the serious dependence on the stator resistance and rotor time constant in the DTC control of induction motor,a parameter estimator was designed based MRAS.This estimator also can observe the stator flux and speed.Simulation results showed the feasibility of the proposed strategy.
Key Words: Speed-sensorless;Three-level inverter;Dummy synthesizing vectors;DTC;Induction motor