基于准PR的LC型并网逆变器双回路控制研究

Research on Dual-loop Control of LC Grid-connected Inverter Based on Quasi-PR

传统并网逆变器控制回路带宽较窄,易受电网电压扰动的影响。针对此问题,这里设计了具有宽带宽的准比例谐振(PR)控制器,大大提高了系统的鲁棒性,同时为抑制电网电压扰动,引入了电网电压前馈控制,大大降低了谐波含量。最后在PSIM平台上搭建了仿真与实验模型,结果表明:基于准PR控制器的双回路控制具有良好的跟踪效果和抗干扰能力,降低了并网电流畸变率,实现了单位功率因数,提高了系统的稳定性能和逆变器输出波形质量。

The control loop bandwidth of the traditional grid-connected inverter is relatively narrow,and it is easily affected by the grid voltage disturbance.To solve this problem,a quasi-proportional resonance(PR)controller with wide bandwidth is designed,which greatly improves the robustness of the system.At the same time,to suppress the grid voltage disturbance,the grid voltage feedforward control is introduced,which greatly reduces the harmonic content.A simulation and experimental model is built on the PSIM platform.The results show that the quasi-PR-based dual-loop control has good tracking effect and anti-interference ability,and it reduces the grid-connected current distortion rate,achieves unity power factor,and improves the stability of the system and output waveform quality of the inverter.