光伏Z源并网逆变器的非线性无源控制研究

RESEARCH ON NONLINEAR PASSIVITY-BASED CONTROL FOR PHOTOVOLTAIC Z-SOURCE GRID-CONNECTED INVERTER

将无源控制（passivity-based control，PBC）这种非线性控制方法首次引入到光伏Z源并网逆变器的控制上，它无需线性化处理就能直接实现有效并网控制，且系统的控制性能优良。首先，根据光伏z源并网逆变器的E-L（Euler—Lagrange）数学模型分析其无源性，并计算得到并网侧幽轴电流解耦的无源控制律；然后，采用注入阻尼方法对控制器进行优化设计，提高系统的动态性能，并实现对给定电压及最大功率点快速跟踪；最后，在Matlab／Simulink软件仿真和硬件样机上实验验证PBC应用到光伏Z源并网逆变器控制上的可行性和有效性，相比于传统电压矢量定向的双闭环控制策略，该系统具有调节时间和上升时间都短、动态性能好、并网功率因数高等特点。

The nonlinear passivity-based control （PBC） method is firstly introduced into the control strategy of photovohaic Z-source grid-connected inverter, it can directly realize effectively grid-connected control without linearization processing, and the system has excellent control performance. Firstly, the passivity is analyzed according to the Euler-Lagrange （E-L） mathematical model of the PV Z-source grid-connected inverter, and the passive control law of the dq-axis current decoupling on the grid-connected side is calculated. Then the controller is optimally designed by injection damping method, the dynamic performance of system is improved, and the fast tracking of the given voltage and the maximum power point is realized. Finally, the feasibility and effectiveness of PBC application to the control of PV Z source grid-connected inverter are verified through experiment on Matlab/Simulink software simulation and hardware prototype, compared to the double-closed loop control strategy of traditional voltage vector orientation, the proposed system has shorter adjusting time and the rising time, better dynamic performance, and higher grid connected power factor.