改进型Z源逆变器

Improved Z-source inverter

针对传统Z源逆变器的直流升压因子较小、启动冲击严重、直流侧的电压利用率较低等缺点,提出了一种改进型的Z源逆变器拓扑。在传统拓扑中加入一个电感和一个全控开关,提高了直流升压因子,利用该电感上的电流不能突变的特性,使得启动时阻抗网络上的电容的冲击电流大幅减小,从而不需要采用软启动策略;同时该拓扑还保证了输入电流连续,减小了对直流源使用寿命的影响,提高了直流侧电压利用率。在理论研究的基础上,基于简单升压控制下的仿真结果验证了该拓扑的正确性与优越性。

Aiming at the low DC boost capacity,serious starting-up inrush current and low DC voltage utilization of traditional Z-source inverter,an improved topology of Z-source inverter is proposed.An inductor and an entirely-controllable switch are added to enhance the DC boost capacity and to reduce the inrush current of capacitor during startup.Soft start strategy is thus unnecessary.Continuous input current is ensured,which mitigates the impact on DC source and improves DC voltage utilization.Based on the theoretical analysis,the simulative results for simple boost control demonstrate the correctness and superiority of the improved topology.