光伏微电网并网逆变器的反步控制研究

Backstepping control for grid-connected inverter in photovoltaic micro-grid

电力电子设备中存在较多非线性的开关元件。在并网逆变器的控制中,如果控制器的控制效果较差,将会对外界电网的稳定性造成影响。针对光伏微电网并网逆变器,基于矢量控制设计了一种反步控制器,意在提高逆变器的控制效果及微电网的并网电能质量。推导了并网模式下光伏微电网逆变器的数学模型,基于所推导的模型利用反步法设计了控制器,并采用李雅普诺夫稳定性理论证明了反步控制策略下系统的稳定性。利用MATLAB/SIMULINK软件环境对系统进行了仿真验证,并将反步控制器与传统PI控制器的控制效果行了对比,验证了反步控制的先进性。

There are many nonlinear switching elements in power electronic equipment. In the control of grid-connected inverter, if the controller has poor control performance, it will affect the stability of external power grid. A backstepping controller based on vector control is designed in this paper to improve the control effect of the inverter and the power quality of the grid-connected photovoltaic micro-grid. Then, the mathematical model of photovoltaic micro-grid inverter in grid-connected mode is deduced. Based on the model, the controller is designed by backstepping method, and the stability of the whole system under backstepping control strategy is proved by Lyapunov stability theory. The system is simulated in MATLAB/SIMULINK, and the control effect between backstepping controller and traditional PI controller are compared to verify the advancement of proposed backstepping controller.