三相LCL光伏并网逆变器的新型入网控制策略

A Novel Admission Control Strategy for Three-phase Photovoltaic Grid-connected Inverters Based on LCL Filter

针对基于状态变量反馈的有源阻尼来抑制LCL滤波器谐振的方法会额外增加系统成本和控制复杂度的问题,在系统前向回路中串联陷波滤波器以阻尼LCL的谐振峰,确保系统稳定。入网电流控制采用比例-谐振调节器,减小系统稳态误差并且提高动态响应速度。系统仿真结果验证了该方法的可行性,仿真结果表明陷波器阻尼同样具有理想的阻尼效果,且与PR控制器结合,提高了并网波形的质量。

For the active damping coefficient based on the state variable feedback inhibition of LCL filter resonance method will increase the system cost and control complexity, a control model in series notch filter in front of the system is established to suppress the resonant peak of LCL and guarantee the stability of the system by adjusting the notch filter parameters. The proportional-resonant regulator is used to control the grid-connected current for reducing steady-state errors and improving the dynamic response. The feasibility of the method is verified by the simulation results. The simulation results show that the notch filter has the same ideal damping effect and improves the quality of current waveform by combining with PR controller.