Z源三电平中点钳位逆变器的空间矢量调制方法

A Space Vector PWM Algorithm for Z-Source Three-Level NPC Inverters

为克服双Z源网络三电平中点钳位(NPC)逆变器所需储能元件多、硬件成本高的缺点,研究了一种单Z源网络三电平NPC逆变拓扑,该拓扑仅需要一个输入电源和Z源网络,但是具有与双Z源网络NPC逆变器相同的升压特性。提出了一种适用于Z源三电平NPC逆变器的空间矢量脉宽调制(SVPWM)方法。该方法基于原点变换思想,将三电平SVPWM等效为两电平SVPWM,简化了计算。通过在等效零矢量内合理配置直通矢量,实现了逆变器的升压输出,且最大程度减小了直通动作产生的开关损耗。最后,仿真及实验结果均证实了所提SVPWM方法的有效性。

Existing dual Z-source networks three-level neutral-point-clamped （NPC） inverters are costly with numerous passive elements. To overcome this disadvantage,a topology of Z-source three-level NPC inverter with single Z-source network is introduced. It only needs single input power source and LC impedance network,while achieving the same voltage-boost capability as the inverter using dual Z-source impedance networks. A suitable space vector PWM scheme for Z-source three-level NPC inverter is proposed,which is simple due to the use of two-level modulation principles based on the idea of origin shifting. By carefully inserting the shoot-through vectors into the equivalent zero vectors,the inverter not only maintains the desired boosted ac output voltage but also reduces the switching loss in a maximum extent. Last,simulation and experimental results are included for verifying the validity of the proposed SVPWM algorithm.