基于FB7桥的光伏并网滑模控制策略

Sliding Mode Control Strategy of Photovoltaic Grid Connected Based on FB7 Bridge

提出了一种基于FB7桥三相光伏逆变器的改进型双闭环滑模控制策略。电压外环采用准滑模控制,电流内环采用改进型快速终端滑模控制,减小系统抖振的同时使系统状态在有限时间内收敛为零。该控制策略克服了传统双闭环PI控制抗干扰性、快速性较差的缺点,提高了系统的并网电流质量和抗干扰能力。Matlab/Simulink仿真实验结果表明,与传统双闭环PI控制策略相比,双闭环滑模控制策略可有效降低并网电流的THD,改善了并网电流的质量,同时提高了系统的动态响应速度和抗干扰能力。实验验证了提出的控制策略的准确性和可行性。

An improved double closed-loop sliding mode control strategy based on FB7 bridge three-phase photovoltaic inverter is proposed. The quasi-sliding mode control is used in the voltage outer loop and the improved fast terminal sliding mode control is used in the current inner loop to reduce the system chattering and make the system state converge to zero in a limited time. The control strategy overcomes the shortcomings of traditional double closed-loop PI control such as poor anti-jamming and poor quickness,and improves the quality of grid-connected current and anti-jamming ability of the system. The simulation results of MATLAB/Simulink show that compared with the traditional double closed-loop PI control strategy,the double closed-loop sliding mode control strategy can effectively reduce the THD of grid-connected current,improve the quality of grid-connected current,and improve the dynamic response speed and anti-interference ability of the system. The accuracy and feasibility of the proposed control strategy are verified.