中文摘要：

针对临近空间飞行器电驱动系统的高效控制问题，构建一种三电平逆变器供电永磁同步电机直接转矩控制系统，以减少输出电流的谐波含量，降低转矩脉动，提升驱动系统整体效率。针对三电平逆变器空间电压矢量调制（SVPWM）实现复杂的问题，通过对大、小电压矢量选择的归纳研究，利用矢量的对称性和归一化处理方法，提出一种易于通过可编程器件实现的简洁计算方法，实现不同扇区的统一计算；构建参考矢量的复数表达形式，利用极坐标相角信息简化扇角区间判别。采用Matlab／Simulink分别构建传统两电平逆变器和三电平逆变器直接转矩控制系统进行对比分析，仿真结果验证了该算法在减小电流谐波和削弱转矩脉动方面的有效性。

英文摘要：

Aiming to obtain high efficiency of electrical drives for near-space vehicle, we proposed a novel threelevel inverter DTC method for PMSM, to suppress current harmonic components and toque ripples. Sections 1 and 2 of the full paper explained the proposed method in detail. Their core consists of： ＂In order to bypass the implemen- ting complexity of space vector PWM （SVPWM） for three-level inverter, we have presented a relatively simple calculation method which is easy to implement with field small voltage sectors and through using the principle programmable gate arrays through choosing proper large and of symmetry and normalization. The reference voltage was presented under polar coordinates and vector phase was used to condense the decisions of sectors. The three-level inverter and traditional two-level inverter DTC simulation models were constructed respectively with Matlab/Simulink for comparative analysis＂. The simulation results, presented in Figs. 6 and 7, have shown preliminarily the validity of our proposed method in suppressing efficiently current harmonics and torque pulses.