改进型Z源并网逆变器

The improved Z source grid-connected inverter

针对传统Z源并网逆变器升压能力有限、启动冲击较为严重、输入电流断续造成直流电压利用率低等方面的不足,对传统的阻抗网络进行改进,提出一种改进型Z源并网逆变器拓扑。该拓扑在传统的阻抗网络的基础上增加一个有源开关及电感,与传统阻抗网络中的输入二极管在前级构成一个等效Boost电路,提高了传统Z源逆变器的升压能力,电感的加入也限制了启动冲击电流,并保证了输入电流的连续。在理论分析的基础上,对基于改进型Z源逆变器的单相并网系统进行了仿真及实验研究,结果均表明该拓扑能够以实现单位功率因素并网,且启动过程平缓,输出电能质量好,系统效率高,验证了该拓扑的可行性及性能的优越性。

As for the traditional Z-source inverter has the disadvantages of low boost capacity, serious start impact, the input current intermittent and DC voltage low utilization deficiencies, this paper optimizes the impedance network of the traditional Z-source inverter and proposes a simplified Z-source grid-connected inverter topology. By adding an active switch and inductor, the topology constituted an equivalent Boost circuit in the former class with the input diode in traditional impedance network, so the boost capacity of traditional Z-source inverter was improved; the startup impact current was limited and the input current was maintained continuously. Based on the theoretical analysis, the simulation and experiment on single- phase grid-connected systems with the improved Z-source inverter have been done, and the simulation and experimental results verify the superiority and the feasibility of the tooolo~~.