基于三相光伏并网系统的比例谐振重复控制研究

在分析LCL型的光伏并网系统的运行状态的前提下,针对三相光伏并网系统的稳定性能、输出波形质量的好坏以及电网的抗干扰能力等问题,提出了一种基于比例谐振的重复控制的控制策略。该控制策略利用比例谐振(PR)在其谐振频率处增益无穷大的特点,消除稳态误差,实现电流的无静差跟踪,提高系统的稳态性能;利用传统的重复控制在并网系统稳定以后可以抑制电网的周期性扰动,从而提高系统的动态性能、电网的抗干扰能力以及获得高质量的并网电流波形。最后通过Matlab/Simulink进行仿真验证,结果显示这种改进的重复控制策略能够很好地解决光伏并网的稳定性能、输出波形质量的好坏以及电网的抗干扰能力这类问题。

Study of Three-phase Photovoltaic Grid System Based on the Proportional Resonance Repetitive Control

For the three-phase photovoltaic （pv） grid system stable performance, the output waveform quality, and the anti-interference ability of the power grid, a control strategy based on proportional resonance repetitive control is put forward after analyzing the running state of LCL type photovohaic grid system. The proposed control strategy e- liminates the steady-state error, realizes the current zero steady-state error tracking, and improves the steady-state performance of the system by using the characteristic that the proportional resonant controller has infinite gain at its resonant frequency; Using conventional repetitive control after the interconnection system stability can suppress the periodic disturbance of power grid, so as to improve the dynamic performance of system, the anti-interference ability of the power grid, and obtain high quality grid current waveform. Finally simulation by Matlab/Simulink is conducted, the result shows that the improved repetitive control strategy can be a very good solution to solve the photovoltaic grid stable performance, the anti-interference ability of the output waveform quality and power grid.