基于LCL滤波器的光伏并网逆变器控制策略

在并网逆变器中引入LCL滤波器取代单个电感滤波器.并针对采用LCL滤波器对并网逆变器系统带来的不稳定性,分别对比了以并网电流作为反馈变量和逆变器侧电流作为反馈变量的电流内环控制方法,提出了基于桥臂输出电流闭环与电压外环的双环控制策略.由于以并网电流为反馈变量的控制系统为三阶系统,所提控制系统稳定性和鲁棒性较好.搭建了三...

Control strategy of LCL-filter-based inverter for photovoltaic grid connection

LCL filter is introduced to replace the individual inductance filter of grid-connected inverter.Based on the comparison between grid-side current and inverter-side current taken as its feedback variable of the inner current loop control,a dual close-loop control of inner bridge current loop and outer voltage loop is proposed to remove the instability caused by the inverter system with LCL filter.The control loop with the grid current as its feedback variable is a three-order system,which has good system stability and robustness.A three-phase inverter system for photovoltaic grid connection is established and the performance of MPPT(Maximum Power Point Tracking) and high power factor are realized.The correctness of theoretical analysis and the feasibility of the proposed control strategy are both proved by simulative and experimental results.