直通物理分离型Z源逆变器并网

Grid-connection of isolated shoot-through Z-source inverter

提出一种直通物理分离型Z源逆变器,通过在传统阻抗网络拓扑结构上引入1个二极管、1个电容和1个全控型器件,有效降低了启动冲击电流和Z源网络电容电压应力,实现了升压因子和调制因子的解耦控制,提高了Z源网络的升压能力。基于直通物理分离型Z源逆变器数学模型,研究了以并网电流控制为内环、直流母线电压控制为外环的双闭环PI控制方案。在理论分析的基础上,对直通物理分离型Z源逆变器并网进行仿真及实验研究,结果表明:系统启动电流冲击小,并网功率因数高,鲁棒性强,动态性能稳定,验证了拓扑结构的正确性和控制策略的优越性。

An IST-ZSI（Isolated Shoot-Through Z-Source Inverter） topological structure is proposed,which adds a diode,a capacitor and an entirely-controllable device to the traditional impedance network to effectively reduce the startup inrush current and the voltage stress of Z-source network capacitor,realize the decoupling control between Boost factor and modulation index,and improve the Boost capability of Z-source network. A double close-loop PI control scheme,including the grid-connecting current control inner-loop and the DC-link voltage control outer-loop,is studied based on the mathematical model of IST-ZSI. The IST-ZSI grid- connection is studied based on the theoretical analysis via simulation and experiment,and the simulative and experimental results show that,the system with IST-ZSI has lower startup inrush current,higher grid- connection power factor,stronger robustness and better dynamic performance ,verifying the correctness of the proposed topology and the superiority of its control strategy.