基于改进重复控制的光伏并网逆变器综合控制策略

Integrated Control Strategy of PV Grid Inverter with Improved Repetitive Control

针对光伏并网逆变器系统的非线性特性,在固定参数准比例谐振(PR)控制方法的基础上,提出了一种准PR控制和重复控制相结合的综合控制策略;并对传统的重复控制进行了改进,在内模环节中引入低通FIR数字滤波器,简化了重复控制器的设计,提高了对系统谐波的抑制能力。Matlab/Simulink仿真实验结果表明:与准PR控制方法相比,准PR控制和重复控制相结合的综合控制策略并网电流具有较低的谐波含量,可以获得高质量的并网电流波形,且系统具有较好的动态和稳态性能。

For nonlinear characteristics of a PV grid-connected inverter, a comprehensive con-trol strategy combining quasi-proportional resonant （PR） control with repetitive control is proposed based on fixed parameters of the quasi-PR control. The conventional repetitive control is improved, an FIR low-pass digital filter introduced into the mold segment, the repetitive controller design sim-plified, and the ability of suppressing harmonics improved. Simulation with Matlab/Simulink shows that, compared with quasi-PR control, the proposed integrated control has a lower harmonic con-tent, and can get high quality of net current waveforms. The system has good dynamic and steady- state performance.