中文摘要：

针对传统直接转矩控制系统存在低速运行时转矩脉动较大的问题，在对电压矢量和转矩脉动生成的关系进行分析和验证的基础上，提出了一种利用零矢量代替反向矢量的方案，同时对转矩和磁链的滞环控制器进行改进优化，用来解决转矩脉动大的问题.仿真结果表明：采用该方案后转矩脉动从4 N·m降至1.5 N·m左右，优化了系统性能，拓展了系统低速调节范围.

英文摘要：

Aiming at the problem of high torque ripple at low speed in traditional direct torque control system, a method of replacing reverse-vector with zero vector is proposed on the basis of analyzing and verifing the relationship between voltage vectors and torque ripple. Additionally, it is adopted to optimize the hysteresis controller of torque and flux linkage, both of which are utilized to solve the problem on high torque ripple. The simulation results indicate that this proposal can decrease torque from 4 N·m to 1.5 N·m, optimizes system performance and extends the low-speed range.