中文摘要：

将Z源逆变器应用到单级单相光伏并网系统中。该逆变器集成了最大功率跟踪（maximum—power—point—tracking，MPPT）、升／降直流侧电压和并阀发电三个功能。根据系统要求以及z源网络在直流侧表现出的非最小相位的特性，该文提出使用两个具有积分补偿的固定频率滑模控制器以保证系统的鲁棒性，以此消除非最小相位特性给系统带来的不良影响，保证Z源电容电压不产生超调和振荡，从而并网电流不发生畸变。该文利用小信号法分析了该闭环系统的稳定性。仿真和实验结果均验证文中提出的逆变器和控制方法的正确性和有效性。

英文摘要：

A Z-source inverter is used for the single-phase grid-connected photovoltaic （PV） system. The inverter integrates three functional blocks including maximumpower-point-tracking （MPPT）, step-up/down DC-side voltage and output grid-connected current. According to the non-minimum-phase characteristic presented in the DC-side and the functional demands of the system, two constant-frequency sliding-mode controllers （SMCs） with integral compensation are proposed to guarantee the system robustness. By using two controllers, the effects caused by the non-minimum-phase characteristic are mitigated. So the over-shoot/under-shoot and fluctuation of the voltage of the Z-source capacitor is eliminated and the quality of grid-connected current is ensured. A small-signal modeling method is employed to analyze the close-loop system. The correctness and validity of the inverter and proposed control algorithm are proved by simulation and experimental results.