单相LCL并网逆变器新型电流控制策略研究

Research on New Current Control Strategy of Single Phase LCL Grid-connected Inverter

LCL型并网逆变器是一个3阶多变量系统,并网电流单环控制难以满足系统的稳定性。为此提出了以电容电流为内环反馈,以并网电流为外环反馈的新型双环控制策略。内环采用比例调节增加系统阻尼以抑制高频谐振问题,外环采用模糊PR+重复控制在线调节系统干扰的影响,实现系统高电能质量并网。仿真和实验结果验证了该控制策略的可行性,并与PR+重复控制相比较,该控制策略具有良好的稳定性和鲁棒性。

LCL-type grid-connected inverter is a three-order multivariable systems,grid connected current single loop control is difficult to meet the stability of the system. A new double-loop control strategy which the inner-loop used capacitor current feedback and the outer-loop adopted grid-connected current feedback was proposed.The inner-loop used proportional regulation to increase the system damping,to suppress high frequency resonance problems;the outer-loop adopted fuzzy PR+repeat control to adjust the influence of system interference on-line,to achieve high power quality network of the system. Simulation and experiment results demonstrate the feasibility of the proposed control system,and compare with PR control and DR control combined with repetitive control to prove that the control method has good stability and robustness.