中文摘要：

针对三电平逆变器控制策略复杂以及存在中点电位不平衡的问题,对其电压空间矢量脉宽调制（SVPWM）原理进行了研究。采用了一种新的方法———首发矢量为正小矢量的SVPWM算法,将所有扇区都变换到第一扇区,简化了控制算法,给出了第一扇区各个小区间的判断规则,推导了合成参考电压矢量的各个基本电压矢量的作用时间,并介绍了SVPWM信号的产生方法。采取了一种新的控制策略———改变小矢量作用时间的方法解决了中点电位不平衡问题。此外,对系统进行了MATLAB仿真,证实了采取SVPWM算法的有效性和控制策略的优越性。

英文摘要：

Aiming at control strategy complication of three-level inverter and potential unbalancing problem of middle point,the principle of space vector pulse width modulation（SVPWM）is deeply refearched.A new method of SVPWM algorithm is adopted by using positive small vector as first active vector.All sectors are transformed to the first sector,which makes the algorithm simple.The judgment rule of the small intervals is given,the action time of basic voltage vectors that compose the reference voltage vectors is derived,and the method of generating SVPWM signal is introduced.Moreover,a new control strategy of action time for changing small vectors is adopted.Furthermore,MATLAB simulation for system is carried out,it indicates the effectiveness of SVPWM algorithm and the superiority of control strategy.