基于控制因子三电平空间矢量方法的研究

Research on Space Vector PWM based on Control Factor in Neutral-Point Clamped Three-level Inverter

介绍一种基于控制因子的三电平空间矢量方法。该控制方法通过检测直流侧电压和中点电流的方向来合理选择控制因子,从而合理分配小矢量P,N状态作用的时间,以解决三电平逆变器中点电位不平衡的问题。另外,在开关序列安排上采用典型的7段法,每相开关序列的变换都只有一次。因此,该方法还具有开关损耗小的特点。最后采用Matlab的Simulink工具,对基于控制因子的空间矢量方法进行了仿真,比较了典型控制因子情况下的等效载波以及对中点电位的影响。实验结果验证了该方法的特点。

A new Space Vector Pulse Width Modulation(SVPWM) method based on control factor is proposed. Base on judging the DC Voltage and the direction of Neutral-Point current. this method selects the control factor to solve the problem of the unbalance of Neutral-Point voltage in Neutral-Point Clamped Three Level Inverter(NPCTLI). Because switching sequence in every phase only changes once,switching losses are reduced.Consequently several typical cases of different control factor are simulated with Simulink tool of Matlab.The simulative and experimental results verify the characteristic of this SVPWM method.