摘要：运用电机空间矢量分析法详细推导了异步电机电磁转矩的空间矢量表达式，剖析了电磁转矩产生的物理机理，说明了转矩系数与空间矢量定义系数的对应关系；以异步电机直接转矩控制（DTC）的基本原理和系统结构为基础，搭建了异步电机直接转矩（DTC）控制系统的Simulink仿真模型；仿真结果证明所建异步电机DTC系统仿真模型正确、参数设置合理，同时反映出DTC系统动态响应迅速、存在转矩和磁链脉动等性能特点。

关键词：电磁转矩表达式；空间矢量；异步电机；直接转矩控制

Abstract: The electromagnetic torque expressions expressed by space vectors were derivated in detail applying space vector analysis mothed. The physical mechanism of the electromagnetic torque were dissected, meanwhile the relation btween the value of torque constant and the constant used in space vector was explained. The theory and structure of direct torque control system（DTC）for asynchronous motor were searched. Then based on the Matlab/Simulink simulation platform, a simulation model of direct torque control system for asynchronous motor was built up. The result of the simulation indicates that the simulation model of DTC system for asynchronous motor is correct and its parameters are set reasonably. The performance characteristics of DTC system such as the quickly torque rsponse and the ripples of torque and flux are also demonstrated by the simulation results.

Key words: electromagnetic torque expressions; space vector; aynchronous motor; direct torque control