基于PR控制和虚拟阻抗的光伏并网逆变器的研究

设计了一种采用准比例谐振控制零稳态误差的光伏并网逆变器控制系统。与常规的PI控制相比,该控制方法可对正弦输入信号进行无静差跟踪,同时克服了常规比例谐振(PR)控制器抗电网频率波动能力差的缺点。此外,结合虚拟阻抗技术,改善了传统LCL输出滤波器的性能,实现对LCL滤波器高频谐振的有效抑制而又不带来系统功率损耗。仿真试验证明,基于准比例谐振控制和虚拟阻抗技术的光伏并网逆变器具有良好的稳态性能和抗干扰能力。

Research of PV Grid-Connected Inverter Based on Proportional-Resonant Control and Virtual Impedance

A zero steady-state error control system of photovoltaie grid-connected inverter was designed which adopts quasi-proportional resonant control. Compared with the conventional PI control, the method can do no static error tracking, while overcoming conventional proportional-resonant （PR） controller＇s poor-anti grid frequency fluctuations capability. In addition, the combination of virtual impedance technology improves the performance of traditional LCL output filter, and the high-frequency resonance of the LCL filter is effectively inhibited without bringing the system power loss. The simulation experiments show that the photovoltaic grid-connected inverter based on quasi- proportional resonant control and virtual impedance technology has good steady-state performance and anti- jamming capability.